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A case series of dermoids in the middle ear
International Journal of Pediatric Otorhinolaryngology xxx (xxxx) xxx
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A case series of dermoids in the middle ear Shubin Chen *, Yanran Huang, Yongxin Li Department of Otolaryngology Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China
A R T I C L E I N F O
A B S T R A C T
Keywords: Case series Dermoid Endoscope Eustachian tube Microscope Middle ear
Objective: Dermoid is a rare disease located in the head and neck and only sporadic cases were previously re ported. Surgery with different operational paths is the best solution to the disease. We aimed to analyze the clinical characteristics and outcomes of surgical approach for treating dermoid originated from the middle ear and Eustachian tube. Methods: In this retrospective case series, four cases of dermoids of the middle ear and Eustachian tube, treated by endoscopic-assisted surgical approach were reviewed and analyzed. Results: Patients’ ages ranged from 7 months to 16 years. All cases involved the middle ear, eustachian tube, and the parapharyngeal space. Postoperative follow-up ranged from 6 months to 11 years. No facial nerve paralysis was observed during or after surgeries. Treatment was efficient in the four cases, with no residual symptoms during post-operative follow-up. Conclusions: Dermoid of the middle ear involving the eustachian tube usually appears in children of early age. Surgical resection with assistance of endoscope has satisfying outcome for these cases.
1. Introduction Dermoid is benign mass consisted of disorganized mesodermal and ectodermal constituents, consisting heterogeneous elements such as squamous epithelium and skin adnexal (hair, hair follicles, sebaceous glands, sweat glands, etc.) [1]. As a relatively rare disease, dermoid accounts for about 7% tumours of head and neck [2]. What’s more, it is extremely rare in the middle ear and Eustachian tube. Only sporadic cases have been previously reported [3,4]. The aetiology of dermoid is still unclear, which is considered to be associated with the aberrant embryologic development in the third to sixth week of gestation [5], such as the failure of ectoderm separating from the neural tube and erroneous fusion between the first and second branchial arches of the head and neck region [2,6]. As benign lesion, dermoid tends to grow at a slow rate over time asymptomatically until it eventually leads to clinical symptoms when it becomes so large that surrounding structures were obstructed or compressed [3]. So far, the surgical intervention has been the mainstay of treatment. In recent years, the use of endoscopy has become more and more com mon in otologic surgeries. Endoscopy is beneficial for accomplishment of satisfying operative field with less invasiveness. In 2014, Presutti et al. [7] advocated combined lateral microscopic/endoscopic surgery to
the lateral skull base. Thus, the aim of this study is to present four cases of this rare disease in the middle ear and Eustachian tube, discuss the clinical characteristics of the disease, and to highlight the surgical approach of combined microscopic/endoscopic procedure with less destruction. 2. Material and methods The clinical records of patients with dermoid in the middle ear at Beijing TongRen Hospital were retrospectively reviewed from January 2009 to January 2020. Only cases of dermoids which were histopatho logically confirmed were enrolled into this study. The study protocol was approved by the Institutional Review Board of Beijing TongRen Hospital. As this was a case series, consents were exempt. We analyzed the clinical characteristics of the four cases, such as gender, age, clinical manifestations, images, pathological data, surgical approach and recurrence. We compared the characteristics of dermoid according to their location. Postoperative follow-ups were also documented.
* Corresponding author. Department of Otolaryngology Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, No.1, Dongjiaominxiang, DongCheng District, Beijing, 100730, PR China. E-mail address: [email protected] (S. Chen). https://doi.org/10.1016/j.ijporl.2020.110472 Received 14 August 2020; Received in revised form 25 October 2020; Accepted 25 October 2020 Available online 4 November 2020 0165-5876/© 2020 The Authors. Published by Elsevier B.V. This is an open
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Please cite this article as: Shubin Chen, International Journal of Pediatric Otorhinolaryngology, https://doi.org/10.1016/j.ijporl.2020.110472
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3. Results
caseous-like material in the cavity, but a niche-like structure with skin, hair and cartilage was found at the inferior part of the lesion (Fig. 2A and B). Thus, the lesion was diagnosed as dermoid cyst. On macroscopic examination, the lesion was a cystic mass composed of cartilage and focal calcification, covered by hair-bearing skin with skin appendage (Fig. 5A). A histopathologic analysis revealed that the lesion was morphologically consistent with dermoid cysts. The patient was dis charged at the 7th day after surgery. The follow-up at 15 months revealed no recurrence of the tumor or otorrhea. No eustachian tube dysfunction such as muffled hearing and a feeling of fullness in the ear, was mentioned.
3.1. Clinical manifestation 3.1.1. Case 1 Case one was a 16-year-old adolescence female presented with recurrent right-sided foul-smelling otorrhea for two months. Three weeks ago, the discharge became hemorrhagic. One week ago, the pa tient developed fever, neck swelling and trismus. The above symptoms were partly alleviated by topical and oral antibiotics. Otoscopic exam ination revealed that the patient’s right ear was occluded with muco purulent debris, so the tympanic membrane could not be observed through external auditory canal (EAC). The nasopharynx, larynx and vocal cords were normal. A conductive hearing loss was found. Com plete blood and platelet counts were normal. Temporal bone computed tomography (CT) showed complete opacification of the right middle ear and mastoid with extension into parapharyngeal space and diffuse erosion of the ossicles (Fig. 1A). Also, destruction of carotid artery canal and erosion of facial nerve canal could be observed. Magnetic resonance imaging (MRI) showed a mass in the right middle ear cavity and para pharyngeal space. The mastoid is full of inflammation signal. The mass appeared low signal intensity on T1-weighted MRI, high signal intensity on T2-weighted MRI, and intense enhancement around the mass (Fig. 1B, C, D). Diffusion weighted imaging (DWI) showed significant higher signals. The preoperative diagnosis of congenital cholesteatoma with parapharyngeal abscess was made. A wall-down mastoidectomy and parapharyngeal mass excision assisted by endoscope were per formed. Most of the mass appeared as cholesteatoma with abundant
3.1.2. Case 2 Case 2 was a 1-year-old male presented to our department com plaining for a history of right-sided otorrhea for eight months. Otoscopic examination revealed a pale mass of right EAC. ABR revealed a mild conductive hearing loss for the left ear. CT scan (Fig. 3A) was performed and showed opacification of the left middle ear and mastoid, enlarge ment of the left eustachian tube with soft tissue, and extension to the left parapharyngeal space. The ossicular chain was partially eroded. On MRI, a well-defined lesion with a maximum diameter of 26 mm was found in Eustachian tube and parapharyngeal space on the right side. The lesion was hyperintense on T1-and T2-weighted sequences, did not enhance with administration of a gadolinium-based contrast agent, and showed a marked signal loss on a fat-saturated T1-weighted sequence (Fig. 3B–D). A wall-down mastoidectomy and parapharyngeal mass excision assisted by endoscope were performed. The lesion was a polypoid, hairy, skin-covered, pedunculated mass in the dilated
Fig. 1. Imaging findings in Case 1. A Results of CT. Neoplasms located in eustachian tube and parapharyngeal space. B-D Magnetic resonance imaging. The lesion in the parapharyngeal space showed a hyperintensity on axial T1 -weighted sequences (B), hyperintensity on axial-T2-weighted sequences (C), intense enhancement around the mass on coronal enhanced T1-weighted sequences (D). 2
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dysfunction were complained. 3.1.4. Case 4 Case 4 was a 7-month-old female presented with a history of inter mittent right otorrhea for 4 months. Otoscopic examination showed a narrowed swollen left EAC, the tympanic membrane was not seen clearly. The ABR revealed a right-sided mild-to-moderate conductive hearing loss. Temporal bone CT scans showed opacification of the right middle ear and mastoid involving the EAC and bony portion of the Eustachian tube. On MRI, the right mastoid was filled with inflammation signals, but a well-demarcated lesion with a maximum diameter of 22 mm was found in the right middle ear and eustachian tube area. The lesion showed the signal intensity of fat on T1-and T2-weighted images. A wall-down mastoidectomy and parapharyngeal mass excision assisted by endoscope were performed. The mass was a polypoid, skin-covered neoplasm, located in the antrum, middle ear and the dilated eusta chian tube, the mass lied underneath the malleus and incus. After removal the malleus and incus, the surgeon tried to pull the tumor from the eustachian tube to the middle ear slightly, but the root of the mass cannot be seen clearly. Then with endoscope, the mass was put into the Eustachian tube again, and very interestingly, it easily slipped into the nasopharynx. The pedicle was found near the pharyngeal orifice in the Eustachian tube. The pedicle was cut off and the mass was removed from the mouth under the endoscope. The tympanic membrane was repaired without ossicular reconstruction. The pathology showed that the mass was skin-covered and with a fibroadipose tissue and cartilage core (Fig. 5B). The focal salivary gland was also found. The squamouscolumnar epithelium junction was seen at the stalk of the tumor (Fig. 5B). The lesion was diagnosed as dermoid (hairy polyps). The pa tient was discharged at the 7th day after surgery. The postoperative course was satisfying. A follow-up at 6 months revealed no recurrence of the mass or otorrhea. The summary of demographical and clinical features of 4 cases were presented as Table 1 and Table 2. All of the four patients underwent a microscope wall-down mastoidectomy and endoscopic-assisted eusta chian tube/or parapharyngeal mass excision instead of transcervical or transparotid surgery. Postoperative pathological examination proved that the neoplasm was dermoid mass with skin, cartilage, and hair. According to the gross appearance and the pathologic characteristics the dermoid masses were divided into two subtypes, dermoid cyst and hairy polyps. One case was dermoid cyst, the other three cases were hairy polyps.
Fig. 2. Surgical findings in Case 1. A Microscope view of the lesion after mastoidectomy showed cholesteatoma-like mass in the eustachian tube and parapharyngeal space. B. Endoscopic view of the lesion after removing cholesteatoma-like mass, showing hairy mass within a niche just before the tip of the styloid process.
eustachian tube. The attachment site was in the cartilage portion of the eustachian tube and very close to the pharyngeal orifice (Fig. 4A and B). The pathology showed as a dermoid (hairy polyps).The patient was discharged at the 7th day after surgery. A follow-up at 10 years revealed no recurrence and normal facial nerve function. No otorrhea or patulous eustachian tube symptoms occurred. 3.1.3. Case 3 Case 3 was a 11-month-old female presented with a history of intermittent left otorrhea for one month. Otoscopic examination showed a left EAC mass, which was white obscuring tympanic membrane. The ABR revealed a left-sided mild-to-moderate conductive hearing loss. Temporal bone CT scans showed opacification of the left middle ear and mastoid involving the EAC and bony portion of the eustachian tube. On MRI, a well-defined lesion with a maximum diameter of 24 mm was found in parapharyngeal space on the left side. The lesion was hyper intense on T1-and T2-weighted sequences without enhancement with administration of a gadolinium-based contrast agent, and showed a marked signal loss on a fat-saturated T1-weighted sequence. A walldown mastoidectomy and parapharyngeal mass excision assisted by endoscope were performed. The mass was a polypoid, pediculate, skincovered neoplasm, located in the anterior tympanum and the dilated eustachian tube. Slightly extract the tumor from the eustachian tube towards the middle ear cavity, extend the endoscope into the expanded eustachian tube, and look for the tumor origin under the endoscope. The mass emanated from a pedicle near the pharyngeal orifice of the eustachian tube. The pedicle was cut off and the mass was removed from the eustachian tube. The pathology showed that the mass was skincovered and with a fibroadipose tissue and cartilage core. The lesion was diagnosed as dermoid (hairy polyps). The patient was discharged at the 7th day after surgery. A follow-up at 5 years revealed no recurrence and normal facial nerve function. No symptoms of eustachian tube
3.2. Surgical procedure Combined microscopic/endoscopic approaches were performed in all cases. Lesions were managed to be removed successfully avoiding transcervical approach without mobilizing the internal carotid artery (ICA). Three patients with hairy polyps underwent radical mastoidec tomy under the microscope, and then the tumor pedicle was found under the endoscope. The tumor pedicle was located in the eustachian tube. After cutting off the pedicle, the tumor can be removed through the middle ear or oral cavity. The tympanic membrane was reconstructed with the temporal muscle. Thus, we only provide the detailed surgical procedure of case one with dermoid cyst. After the retroauricular incision was made, a pedicled temporal musculoperiosteal flap was prepared. A wall-down mastoidectomy was performed. On surgical intervention, it was found perforation of the tympanic membrane, and granulations protruding into EAC. After removing granulations, it was seen that a white mass resembling epidermoid cysts filling the whole middle ear cavity and bony portion of eustachian tube. The ossicle chain was partially eroded, surrounding by granulations. The malleus and incus were removed. The stape was found intact. The tympanic portion of the facial nerve was fully exposed. After most of the tympanic bone was removed, it was noted that the epider moid cyst (cholesteatoma) protruded into the parapharyngeal space 3
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Fig. 3. Imaging findings in Case 2. A Results of CT. Neoplasms located in the eustachian tube and parapharyngeal space. B-D Magnetic resonance imaging, a welldefined lesion with a maximum diameter of 26 mm was found in eustachian tube and parapharyngeal space on the right side. The lesion was a T1-hyperintense (B) and T2-hyperintense (C), and a marked signal loss on a fat-saturated T1-weighted sequence (D).
with pus (Fig. 2A). Then temporomandibular joint was pulled forward to fully expose the bony part of the eustachian tube. The bone tube of the eustachian tube was destroyed, and the bony part of the eustachian tube was ground to the cartilage part of the eustachian tube. Under the mi croscope, destruction of vertical segment of carotid artery canal was confirmed, and the pulsation of the carotid artery could be seen. The facial nerve and parotid gland were exposed. For the lesions in the parapharyngeal space could not be shown clearly by microscope, then the space was examined by endoscopy (0degree and 30-degree). Meticulous dissection between the mass capsule and surrounding tissues was performed under endoscopic magnified visualization. On the medial side, the carotid artery sheath was identi fied and the mass capsule was separated carefully from the vital struc tures of the carotid artery sheath from the top to the bottom. On the lateral side, the mass was dissected from the fascia of medial pterygoid muscle. At last, a 30-degree endoscope showed a niche-like structure consisted of hair, skin and cartilage, it was located just before the tip of the styloid process at the bottom of prestyloid parapharyngeal space (Fig. 2B). The main point of endoscope surgery was to identify the in ternal carotid artery as early as possible and then carefully separate tumor along the surface of the carotid sheath. After completely removing neoplasm, the pedicled temporal mus culoperiosteal flap was inserted into the parapharyngeal cavity. Fascia musculus temporalis was placed on the surface of the stape. The mea toplasty was made after excision of concha cartilage.
4. Discussion Dermoid is rare in the middle ear cleft. Because of its slow-growing nature, it usually remains symptom-free until it is large enough to involve the surrounding structures, which makes it usually difficult to access during surgery [1]. In this study, we performed four cases of such lesion which were successfully removed through combined-microscopy/endoscopy approach achieving a satisfying operative field and adequate operative space without further re currences. What’s more, the invasiveness of surgery was limited through microscopic/endoscopic resection avoiding transcervical approach. As mentioned above, the aetiology of dermoid is considered to be associated with the aberrant embryologic development, which makes it possible to be relatively common in paediatric patients. Three out of the four cases we reported were infants, while one was adolescent female. Our finding is in line with previous reports [8–12]. The clinical symp toms were relatively mild, such as intermittent otorrhea, mild conduc tive hearing loss and so on. It could be explained by the latent development of the disease. It only came to symptomatic with expansion to parapharyngeal space and eustachian tube. Symptoms worsen when parapharyngeal space infection occurs, as case 1. Histopathologically, dermoid is comprised of ectodermal and mesodermal derivatives [13]. The mesodermal components often include fat, cartilage and muscle, while the ectodermal layer is comprised of a keratinizing squamous epithelial layer with adnexal structures, such as hair follicles. In the previous literature, terms such as dermoid [3,5], dermoid cyst [1,14], hairy polyps [15], hamartomas [9, 16], teratoma [8], and cholesteatoma have been used interchangeably 4
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Fig. 4. Surgical findings in Case 2. An Endoscopic view of the lesion, showing a polypoid, skin-covered, hairy mass within the eustachian tube. B Endoscopic view of the lesion after partly resection of the mass, the pedicle (origin) of the mass is at the pharyngeal orifice of eustachian tube (asterisk), the nasopharynx can be seen through the dilated eustachian tube (arrow).
Fig. 5. Characteristically pathological image (100× magnified) in Case 1 (A) and 4 (B), manifesting skin (white arrow), sebaceous glands (black arrow), cartilage (asterisk), adipose tissue (triangular) and hair follicles (diamond).
to describe the dermoid lesion in the middle ear and eustachian tube. According to the 2016 WHO classification of tumours of the central nervous system [17], teratoma is defined as a germ cell tumour composed of somatic tissues derived from two or three of the germ layers (i.e. the ectoderm, endoderm, and mesoderm). Thus, dermoid can be regarded as to be a bigeminal teratomas derived from both ectodermal and mesodermal elements. Based on the literature review and our cases, we suggest dermoid in the middle ear and Eustachian tube can be classified into 2 subtypes according to gross appearance: (1) Dermoid cyst, which presents as a cystic mass without a stalk, and which has a lumen lined by keratinized and stratified squamous epithelium and containing keratin and hair in it, just as in our case 1. (2) Hairy polyp, which appear as a sausage-like polyp with a pedicle, the cover is skin and hair, and the inside is fat, cartilage and muscle, just as our case 2,3,4. According to article reviews [18–20] the salivary gland tissue might be found in some cases, just as in our cases 4. In our cases, the stalk of hairy polyps is at the Eustachian tube, which is lined with respiratory ciliated mucosa, thus the squamous-columnar junction can be found at the stalk. The two subtypes of dermoid can have different imaging signs, especially on MRI. Dermoid cyst in the middle ear cleft may have similar imaging features with cholesteatoma, thus preoperative diagnose of the cholesteatoma was made in case 1.Hairy polyps in the middle ear and Eustachian tube may show occlusion inflammation signs in the mastoid and middle ear, enlargement of bony part of Eustachian tube, and the mass itself may show similar imaging characteristics as hairy polyps in the oral-nasopharynx. Upon MRI scan, a hairy polyp in the oralnasopharynx is usually shown as polyp-like, well-circumscribed, pedunculated mass with a fat density or signal which can be approved by fat-suppression technique [21–24]. The mass in oral-nasopharynx is usually not enhanced and the stalk of it is clearly identified on MRI imaging. Otherwise, when the hairy polyp was located in the middle ear and Eustachian tube, the stalk was not easily identified and the surface might be enhanced due to inflammation on MRI imaging.
According to the literature, dermoid in the middle ear cleft usually appeared as hairy polyps on the gross appearance. The dermoid appearing as cyst-like mass in the middle ear was extremely rare, not well-documented in the literature. The Eustachian tube might be the most common attachment site of the dermoid in the middle ear cleft. Three of our cases originated from Eustachian tube, the other one originated from the prestyloid parapharyngeal space. The surgical excision is the best solution to these lesions. Surgical routes described in the literature are classified as transoral, transnasal, transtympanic, transmastoid approach, or combined transmastoid/ transcervical approach [4,5,10,11,25]. The use of endoscopy is extremely beneficial for better preservations of the important structures such as the ICA and the facial nerve [26]. For the dermoid mass in the nasopharynx arising from the eustachian tube, which usually presents as a hairy polyp with a stalk near the pharyngeal ostium in the eustachian tube, the endoscopic transoral or transnasal approach is the first choice [27,28]. If its origination in the eustachian tube could not be detected accurately by transnasal endo scope, part of tumour in the eustachian tube may be spared during surgery. In that case, an addition surgery would be needed to further remove the residual tumour. For those whose principal part locating in the middle ear or in the Eustachian tube, transmastoid approach is a good choice. In 1992, Vrabec [29] described a dermoid mass involving the middle ear and eustachian tube. In that case, after the tumor was delivered from the eustachian tube through the middle ear, a rigid telescope was passed from the middle ear to the nasopharynx to ensure complete tumor removal. In recent years, thanks to the development of endoscopy and visualization system, the exact origin of the tumour in the dilated eustachian tube or parapharyngeal space and the relationship to the 5
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Table 1 Demographics and baseline disease characteristics. Case
Age
Sex
Side
Otorrhea
Hearing loss
ICA
Eustachian tube
Parapharyngeal space
Follow-up
1 2 3 4
16Y 1Y 11 M 7M
F M F F
R R L R
2M 8M 1M 4M
Mild Mild Mild-to-moderate Mild-to-moderate
Yes Yes No No
Yes Yes Yes Yes
Yes Yes Yes No
15 M 10Y 5Y 6M
ICA, internal carotid artery. Table 2 Clinical characteristics of 4 cases. Case
Subtype
Tumor involvement
Mass origination
Gross appearance
Pathological examination
1
Middle ear,ET, parapharyngeal space Middle ear,ET
No stalk was found.
Cyst with skin-covered cavity Hairy polyps with a stalk
skin, fat, cartilage
2
Dermoid cyst Hairy polyps
skin, fat, cartilage, fibrous tissues
3
Hair polyps
Middle ear,ET
Hairy polyps with a stalk
skin, fat, cartilage, fibrous tissues
4
Hairy polyps
Antrum, Middle ear,ET
Hairy polyps with a stalk
skin, fat, cartilage, fibrous tissues, glandular tissue
Stalk in the cartilage part of ET Stalk in the cartilage part of ET Stalk in the cartilage part of ET
ET, Eustachian tube.
Ethics statement
carotid canal could be seen clearly. The deep location of the eustachian tube and parapharyngeal space, the proximity of internal carotid artery characterizes the treatment of these lesions as particularly challenging. In our experience, at the beginning, we finished the mastoidectomy under microscope and remove the bony barrier around the bony portion of the eustachian tube and the tympanic part of the temporal bone. If necessary, the anterior wall of the external auditory canal should be removed and the mandible was retracted anteriorly. Then we used the endoscope to examine and removed the tumour in the eustachian tube or parapharyngeal space. The surgeon should keep in mind that the masses might arise closely to the carotid artery and erode the vertical part of carotid canal. As in our cases, there was erosion to the vertical canal in two of them. For the carotid artery in this area is vulnerable, the mass should be removed gently and carefully around the carotid artery. For the hairy polyps usually have a pedicle, it is important to identified the attachment site. After the pedicle was sectioned, the mass can be pulled out through the protympanium or through oro-nasopharynx. As for the dermoid of the ear or eustachian tube, which invading to the parapharyngeal space, only 2 cases were found in the English liter ature [5]. It is reported to be removed through transmastoid approach combined with transcervical or transparotid neck dissection was re ported. In our case 1, the mass was massive, invading into the prestyloid compartment, expanding to the deep lobe of the parotid and beneath the tip of the styloid process. In this case, surgical treatment is very chal lenging. We use the transmastoid approach combined with endoscope, avoiding transcervical parotidectomy. As far as we know, it is firstly reported to successfully treat such lesion involving the parapharyngeal space with endoscopic-combined transmastoid approach.
This retrospective case series was approved by the Review Board of Beijing TongRen Hospital. As this was a case series, consent was exempt. Declaration of competing interest All authors declare no financial or commercial conflicts of interest. Acknowledgement Not applicable. References [1] H.S. Al-Muhaimeed, H.Y. Abdelwahed, E.A. Elgamal, G.M. Alokby, A.M. Binnasser, M.M. Ashraf, Extradural dermoid cyst of mastoid bone: a case report, Case Rep Otolaryngol (2012) 548340, https://doi.org/10.1155/2012/548340, 2012. [2] Y. Cho, D.H. Lee, Clinical characteristics of idiopathic epidermoid and dermoid cysts of the ear, J Audiol Otol 21 (2) (2017) 77–80, https://doi.org/10.7874/ jao.2017.21.2.77. [3] B.R. Campbell, R.J. Yawn, B.P. O’Connell, A. Rivas, Dermoid tumor of the middle ear: a case report and review of the literature, Otolaryngology Case Reports 4 (2017) 18–20, https://doi.org/10.1016/j.xocr.2017.08.003. [4] S. Nalavenkata, C. Meller, M. Forer, N.P. Patel, Dermoid cysts of the Eustachian tube: a transnasal excision, Int. J. Pediatr. Otorhinolaryngol. 77 (4) (2013) 588–593, https://doi.org/10.1016/j.ijporl.2012.12.026. [5] S.S. Kollias, W.S. Ball Jr., E.C. Prenger, C.M. Myers 3rd, Dermoids of the eustachian tube: CT and MR findings with histologic correlation, AJNR American journal of neuroradiology 16 (4) (1995) 663–668. [6] T. Minatogawa, M.N. Node, I. Fukuda, T. Kumoi, Dermoid cyst in the middle ear, J. Laryngol. Otol. 107 (4) (1993) 335–338, https://doi.org/10.1017/ s0022215100122960. [7] L. Presutti, M. Alicandri-Ciufelli, A. Rubini, F.M. Gioacchini, D. Marchioni, Combined lateral microscopic/endoscopic approaches to petrous apex lesions: pilot clinical experiences, Ann. Otol. Rhinol. Laryngol. 123 (8) (2014) 550–559, https:// doi.org/10.1177/0003489414525342. [8] A. Alqurashi, E. Bakry, M. Straube, C.H. Rickert, P. Mir-Salim, Mature teratoma of the temporal bone in 3.5-month-old baby girl, Case Reports in Otolaryngology 2015 (2015) 1–3, https://doi.org/10.1155/2015/372089. [9] S. Baget, A. François, J. Andrieu-Guitrancourt, J.P. Marie, D. Dehesdin, Hamartoma of the middle ear: a case study, Int. J. Pediatr. Otorhinolaryngol. 67 (3) (2003) 287–291, https://doi.org/10.1016/s0165-5876(02)00376-2. [10] J.L. Wang, Z.H. Hou, L. Chen, J. Yuan, S.M. Yang, Combined application of otoendoscopes and nasal endoscopes for resection of dermoid tumor in eustachian tube, Acta Otolaryngol. 131 (2) (2011) 221–224, https://doi.org/10.3109/ 00016489.2010.504738. [11] G. Cantarella, M. Gaffuri, L. Pugni, L. Pignataro, F. Mosca, Severe respiratory distress at birth caused by a hairy polyp of the Eustachian tube: transoral endoscopy-guided treatment, Congenital. Anom. 55 (3) (2015) 158–160, https:// doi.org/10.1111/cga.12100.
5. Conclusions In conclusion, our study showed that dermoid of the middle ear usually appear in children of early ages involving the eustachian tube. The dermoid may appear as hairy polyps or dermoid cyst. The dermoid may originated from eustachian tube or parapharyngeal space. Surgical resection with assistance of endoscope has satisfying outcome for these cases. Funding Not applicable.
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International Journal of Pediatric Otorhinolaryngology xxx (xxxx) xxx [21] S.C. Kochanski, E.M. Burton, F.G. Seidel, L.R. Chanin, S. Hensley, J.D. Acker, Neonatal nasopharyngeal hairy polyp: CT and MR appearance, J. Comput. Assist. Tomogr. 14 (6) (1990) 1000–1001, https://doi.org/10.1097/00004728199011000-00027. [22] L. Cerezal, C. Morales, F. Abascal, A. Canga, J. Gomez, M. Bustamante, Magnetic resonance features of nasopharyngeal teratoma (hairy polyp) in an adult, Ann. Otol. Rhinol. Laryngol. 107 (11 Pt 1) (1998) 987–990, https://doi.org/10.1177/ 000348949810701115. [23] J.K. Kraft, L.C. Knight, C. Cullinane, US and MRI of a pharyngeal hairy polyp with pathological correlation, Pediatr. Radiol. 41 (9) (2011) 1208–1211, https://doi. org/10.1007/s00247-011-2064-9. [24] M. Sheng, Y. Mi, F. Gao, J. Liang, H. Zhou, Imaging features of pharyngeal hairy polyps in infants, Oral Radiol. (2020), https://doi.org/10.1007/s11282-02000430-5. [25] J.L. Roh, Transoral endoscopic resection of a nasopharyngeal hairy polyp, Int. J. Pediatr. Otorhinolaryngol. 68 (8) (2004) 1087–1090, https://doi.org/10.1016/j. ijporl.2004.03.005. [26] H. Kojima, Y. Tanaka, Y. Yaguchi, H. Miyazaki, S. Murakami, H. Moriyama, Endoscope-assisted surgery via the middle cranial fossa approach for a petrous cholesteatoma, Auris Nasus Larynx 35 (4) (2008) 469–474, https://doi.org/ 10.1016/j.anl.2007.09.010. [27] J. Wu, J. Schulte, C. Yang, F. Baroody, D.T. Ginat, Hairy polyp of the nasopharynx arising from the eustachian tube, Head and Neck Pathology 10 (2) (2015) 213–216, https://doi.org/10.1007/s12105-015-0632-2. [28] N. Agrawal, D. Kanabar, G.A. Morrison, Combined transoral and nasendoscopic resection of an eustachian tube hairy polyp causing neonatal respiratory distress, Am. J. Otolaryngol. 30 (5) (2009) 343–346, https://doi.org/10.1016/j. amjoto.2008.06.001. [29] J.T. Vrabec, M.K. Schwaber, Dermoid tumor of the middle ear: case report and literature review, Am. J. Otol. 13 (6) (1992) 580–581.
[12] D. Lepera, L. Volpi, F. De Bernardi, S.A. Shawkat, L. Cimetti, M. Bignami, P. Castelnuovo, Endoscopic transnasal resection of Eustachian-tube dermoid in a new-born infant, Auris Nasus Larynx 42 (3) (2015) 235–240, https://doi.org/ 10.1016/j.anl.2014.10.015. [13] M. Dutta, S. Roy, S. Ghatak, Naso-oropharyngeal choristoma (hairy polyps): an overview and current update on presentation, management, origin and related controversies, Eur. Arch. Oto-Rhino-Laryngol. 272 (5) (2015) 1047–1059, https:// doi.org/10.1007/s00405-014-3050-2. [14] O.C. Luz, L.C. Raquel, S.D.O. Marimar, D.M. Carola, P.L. Carolina, R.M.J.P. D. Ramon, Dermoid cysts: a report of 75 pediatric patients, Pediatr. Dermatol. 30 (6) (2013) 706–711. [15] P. Walker, Dilated Eustachian tube orifice after endoscopic removal of hairy polyp, Otolaryngol. Head Neck Surg. 139 (1) (2008) 162–163, https://doi.org/10.1016/j. otohns.2007.07.032. [16] A.R. Hulsmann, N. de Bont, J.C. den Hollander, J.A. Borgstein, Hamartomas of the oro- and nasopharyngeal cavity in infancy: two cases and a short review, Eur. J. Pediatr. 168 (8) (2009) 999–1001, https://doi.org/10.1007/s00431-008-0865-0. [17] D.N. Louis, A. Perry, G. Reifenberger, A. von Deimling, D. Figarella-Branger, W. K. Cavenee, H. Ohgaki, O.D. Wiestler, P. Kleihues, D.W. Ellison, The 2016 world health organization classification of tumors of the central nervous system: a summary, Acta Neuropathol. 131 (6) (2016) 803–820, https://doi.org/10.1007/ s00401-016-1545-1. [18] P.E. Farris, W.L. Meyerhoff, F. Vuitch, Congenital dermoid cyst of the middle ear, Skull Base Surg. 8 (2) (1998) 77–80, https://doi.org/10.1055/s-2008-1058579. [19] C.G. Gourin, R.A. Sofferman, Dermoid of the eustachian tube, Otolaryngol. Head Neck Surg. 120 (5) (1999) 772–775, https://doi.org/10.1053/hn.1999.v120. a86475. [20] B.M. Cone, M. Taweevisit, S. Shenoda, S. Sobol, E. Schemankewitz, B.M. Shehata, Pharyngeal hairy polyps: five new cases and review of the literature, Fetal Pediatr. Pathol. 31 (3) (2012) 184–189, https://doi.org/10.3109/15513815.2011.648722.
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International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
A case series of dermoids in the middle ear Shubin Chen *, Yanran Huang, Yongxin Li Department of Otolaryngology Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, Beijing, 100730, China
A R T I C L E I N F O
A B S T R A C T
Keywords: Case series Dermoid Endoscope Eustachian tube Microscope Middle ear
Objective: Dermoid is a rare disease located in the head and neck and only sporadic cases were previously re ported. Surgery with different operational paths is the best solution to the disease. We aimed to analyze the clinical characteristics and outcomes of surgical approach for treating dermoid originated from the middle ear and Eustachian tube. Methods: In this retrospective case series, four cases of dermoids of the middle ear and Eustachian tube, treated by endoscopic-assisted surgical approach were reviewed and analyzed. Results: Patients’ ages ranged from 7 months to 16 years. All cases involved the middle ear, eustachian tube, and the parapharyngeal space. Postoperative follow-up ranged from 6 months to 11 years. No facial nerve paralysis was observed during or after surgeries. Treatment was efficient in the four cases, with no residual symptoms during post-operative follow-up. Conclusions: Dermoid of the middle ear involving the eustachian tube usually appears in children of early age. Surgical resection with assistance of endoscope has satisfying outcome for these cases.
1. Introduction Dermoid is benign mass consisted of disorganized mesodermal and ectodermal constituents, consisting heterogeneous elements such as squamous epithelium and skin adnexal (hair, hair follicles, sebaceous glands, sweat glands, etc.) [1]. As a relatively rare disease, dermoid accounts for about 7% tumours of head and neck [2]. What’s more, it is extremely rare in the middle ear and Eustachian tube. Only sporadic cases have been previously reported [3,4]. The aetiology of dermoid is still unclear, which is considered to be associated with the aberrant embryologic development in the third to sixth week of gestation [5], such as the failure of ectoderm separating from the neural tube and erroneous fusion between the first and second branchial arches of the head and neck region [2,6]. As benign lesion, dermoid tends to grow at a slow rate over time asymptomatically until it eventually leads to clinical symptoms when it becomes so large that surrounding structures were obstructed or compressed [3]. So far, the surgical intervention has been the mainstay of treatment. In recent years, the use of endoscopy has become more and more com mon in otologic surgeries. Endoscopy is beneficial for accomplishment of satisfying operative field with less invasiveness. In 2014, Presutti et al. [7] advocated combined lateral microscopic/endoscopic surgery to
the lateral skull base. Thus, the aim of this study is to present four cases of this rare disease in the middle ear and Eustachian tube, discuss the clinical characteristics of the disease, and to highlight the surgical approach of combined microscopic/endoscopic procedure with less destruction. 2. Material and methods The clinical records of patients with dermoid in the middle ear at Beijing TongRen Hospital were retrospectively reviewed from January 2009 to January 2020. Only cases of dermoids which were histopatho logically confirmed were enrolled into this study. The study protocol was approved by the Institutional Review Board of Beijing TongRen Hospital. As this was a case series, consents were exempt. We analyzed the clinical characteristics of the four cases, such as gender, age, clinical manifestations, images, pathological data, surgical approach and recurrence. We compared the characteristics of dermoid according to their location. Postoperative follow-ups were also documented.
* Corresponding author. Department of Otolaryngology Head and Neck Surgery, Beijing TongRen Hospital, Capital Medical University, No.1, Dongjiaominxiang, DongCheng District, Beijing, 100730, PR China. E-mail address: [email protected] (S. Chen). https://doi.org/10.1016/j.ijporl.2020.110472 Received 14 August 2020; Received in revised form 25 October 2020; Accepted 25 October 2020 Available online 4 November 2020 0165-5876/© 2020 The Authors. Published by Elsevier B.V. This is an open
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Please cite this article as: Shubin Chen, International Journal of Pediatric Otorhinolaryngology, https://doi.org/10.1016/j.ijporl.2020.110472
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3. Results
caseous-like material in the cavity, but a niche-like structure with skin, hair and cartilage was found at the inferior part of the lesion (Fig. 2A and B). Thus, the lesion was diagnosed as dermoid cyst. On macroscopic examination, the lesion was a cystic mass composed of cartilage and focal calcification, covered by hair-bearing skin with skin appendage (Fig. 5A). A histopathologic analysis revealed that the lesion was morphologically consistent with dermoid cysts. The patient was dis charged at the 7th day after surgery. The follow-up at 15 months revealed no recurrence of the tumor or otorrhea. No eustachian tube dysfunction such as muffled hearing and a feeling of fullness in the ear, was mentioned.
3.1. Clinical manifestation 3.1.1. Case 1 Case one was a 16-year-old adolescence female presented with recurrent right-sided foul-smelling otorrhea for two months. Three weeks ago, the discharge became hemorrhagic. One week ago, the pa tient developed fever, neck swelling and trismus. The above symptoms were partly alleviated by topical and oral antibiotics. Otoscopic exam ination revealed that the patient’s right ear was occluded with muco purulent debris, so the tympanic membrane could not be observed through external auditory canal (EAC). The nasopharynx, larynx and vocal cords were normal. A conductive hearing loss was found. Com plete blood and platelet counts were normal. Temporal bone computed tomography (CT) showed complete opacification of the right middle ear and mastoid with extension into parapharyngeal space and diffuse erosion of the ossicles (Fig. 1A). Also, destruction of carotid artery canal and erosion of facial nerve canal could be observed. Magnetic resonance imaging (MRI) showed a mass in the right middle ear cavity and para pharyngeal space. The mastoid is full of inflammation signal. The mass appeared low signal intensity on T1-weighted MRI, high signal intensity on T2-weighted MRI, and intense enhancement around the mass (Fig. 1B, C, D). Diffusion weighted imaging (DWI) showed significant higher signals. The preoperative diagnosis of congenital cholesteatoma with parapharyngeal abscess was made. A wall-down mastoidectomy and parapharyngeal mass excision assisted by endoscope were per formed. Most of the mass appeared as cholesteatoma with abundant
3.1.2. Case 2 Case 2 was a 1-year-old male presented to our department com plaining for a history of right-sided otorrhea for eight months. Otoscopic examination revealed a pale mass of right EAC. ABR revealed a mild conductive hearing loss for the left ear. CT scan (Fig. 3A) was performed and showed opacification of the left middle ear and mastoid, enlarge ment of the left eustachian tube with soft tissue, and extension to the left parapharyngeal space. The ossicular chain was partially eroded. On MRI, a well-defined lesion with a maximum diameter of 26 mm was found in Eustachian tube and parapharyngeal space on the right side. The lesion was hyperintense on T1-and T2-weighted sequences, did not enhance with administration of a gadolinium-based contrast agent, and showed a marked signal loss on a fat-saturated T1-weighted sequence (Fig. 3B–D). A wall-down mastoidectomy and parapharyngeal mass excision assisted by endoscope were performed. The lesion was a polypoid, hairy, skin-covered, pedunculated mass in the dilated
Fig. 1. Imaging findings in Case 1. A Results of CT. Neoplasms located in eustachian tube and parapharyngeal space. B-D Magnetic resonance imaging. The lesion in the parapharyngeal space showed a hyperintensity on axial T1 -weighted sequences (B), hyperintensity on axial-T2-weighted sequences (C), intense enhancement around the mass on coronal enhanced T1-weighted sequences (D). 2
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dysfunction were complained. 3.1.4. Case 4 Case 4 was a 7-month-old female presented with a history of inter mittent right otorrhea for 4 months. Otoscopic examination showed a narrowed swollen left EAC, the tympanic membrane was not seen clearly. The ABR revealed a right-sided mild-to-moderate conductive hearing loss. Temporal bone CT scans showed opacification of the right middle ear and mastoid involving the EAC and bony portion of the Eustachian tube. On MRI, the right mastoid was filled with inflammation signals, but a well-demarcated lesion with a maximum diameter of 22 mm was found in the right middle ear and eustachian tube area. The lesion showed the signal intensity of fat on T1-and T2-weighted images. A wall-down mastoidectomy and parapharyngeal mass excision assisted by endoscope were performed. The mass was a polypoid, skin-covered neoplasm, located in the antrum, middle ear and the dilated eusta chian tube, the mass lied underneath the malleus and incus. After removal the malleus and incus, the surgeon tried to pull the tumor from the eustachian tube to the middle ear slightly, but the root of the mass cannot be seen clearly. Then with endoscope, the mass was put into the Eustachian tube again, and very interestingly, it easily slipped into the nasopharynx. The pedicle was found near the pharyngeal orifice in the Eustachian tube. The pedicle was cut off and the mass was removed from the mouth under the endoscope. The tympanic membrane was repaired without ossicular reconstruction. The pathology showed that the mass was skin-covered and with a fibroadipose tissue and cartilage core (Fig. 5B). The focal salivary gland was also found. The squamouscolumnar epithelium junction was seen at the stalk of the tumor (Fig. 5B). The lesion was diagnosed as dermoid (hairy polyps). The pa tient was discharged at the 7th day after surgery. The postoperative course was satisfying. A follow-up at 6 months revealed no recurrence of the mass or otorrhea. The summary of demographical and clinical features of 4 cases were presented as Table 1 and Table 2. All of the four patients underwent a microscope wall-down mastoidectomy and endoscopic-assisted eusta chian tube/or parapharyngeal mass excision instead of transcervical or transparotid surgery. Postoperative pathological examination proved that the neoplasm was dermoid mass with skin, cartilage, and hair. According to the gross appearance and the pathologic characteristics the dermoid masses were divided into two subtypes, dermoid cyst and hairy polyps. One case was dermoid cyst, the other three cases were hairy polyps.
Fig. 2. Surgical findings in Case 1. A Microscope view of the lesion after mastoidectomy showed cholesteatoma-like mass in the eustachian tube and parapharyngeal space. B. Endoscopic view of the lesion after removing cholesteatoma-like mass, showing hairy mass within a niche just before the tip of the styloid process.
eustachian tube. The attachment site was in the cartilage portion of the eustachian tube and very close to the pharyngeal orifice (Fig. 4A and B). The pathology showed as a dermoid (hairy polyps).The patient was discharged at the 7th day after surgery. A follow-up at 10 years revealed no recurrence and normal facial nerve function. No otorrhea or patulous eustachian tube symptoms occurred. 3.1.3. Case 3 Case 3 was a 11-month-old female presented with a history of intermittent left otorrhea for one month. Otoscopic examination showed a left EAC mass, which was white obscuring tympanic membrane. The ABR revealed a left-sided mild-to-moderate conductive hearing loss. Temporal bone CT scans showed opacification of the left middle ear and mastoid involving the EAC and bony portion of the eustachian tube. On MRI, a well-defined lesion with a maximum diameter of 24 mm was found in parapharyngeal space on the left side. The lesion was hyper intense on T1-and T2-weighted sequences without enhancement with administration of a gadolinium-based contrast agent, and showed a marked signal loss on a fat-saturated T1-weighted sequence. A walldown mastoidectomy and parapharyngeal mass excision assisted by endoscope were performed. The mass was a polypoid, pediculate, skincovered neoplasm, located in the anterior tympanum and the dilated eustachian tube. Slightly extract the tumor from the eustachian tube towards the middle ear cavity, extend the endoscope into the expanded eustachian tube, and look for the tumor origin under the endoscope. The mass emanated from a pedicle near the pharyngeal orifice of the eustachian tube. The pedicle was cut off and the mass was removed from the eustachian tube. The pathology showed that the mass was skincovered and with a fibroadipose tissue and cartilage core. The lesion was diagnosed as dermoid (hairy polyps). The patient was discharged at the 7th day after surgery. A follow-up at 5 years revealed no recurrence and normal facial nerve function. No symptoms of eustachian tube
3.2. Surgical procedure Combined microscopic/endoscopic approaches were performed in all cases. Lesions were managed to be removed successfully avoiding transcervical approach without mobilizing the internal carotid artery (ICA). Three patients with hairy polyps underwent radical mastoidec tomy under the microscope, and then the tumor pedicle was found under the endoscope. The tumor pedicle was located in the eustachian tube. After cutting off the pedicle, the tumor can be removed through the middle ear or oral cavity. The tympanic membrane was reconstructed with the temporal muscle. Thus, we only provide the detailed surgical procedure of case one with dermoid cyst. After the retroauricular incision was made, a pedicled temporal musculoperiosteal flap was prepared. A wall-down mastoidectomy was performed. On surgical intervention, it was found perforation of the tympanic membrane, and granulations protruding into EAC. After removing granulations, it was seen that a white mass resembling epidermoid cysts filling the whole middle ear cavity and bony portion of eustachian tube. The ossicle chain was partially eroded, surrounding by granulations. The malleus and incus were removed. The stape was found intact. The tympanic portion of the facial nerve was fully exposed. After most of the tympanic bone was removed, it was noted that the epider moid cyst (cholesteatoma) protruded into the parapharyngeal space 3
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Fig. 3. Imaging findings in Case 2. A Results of CT. Neoplasms located in the eustachian tube and parapharyngeal space. B-D Magnetic resonance imaging, a welldefined lesion with a maximum diameter of 26 mm was found in eustachian tube and parapharyngeal space on the right side. The lesion was a T1-hyperintense (B) and T2-hyperintense (C), and a marked signal loss on a fat-saturated T1-weighted sequence (D).
with pus (Fig. 2A). Then temporomandibular joint was pulled forward to fully expose the bony part of the eustachian tube. The bone tube of the eustachian tube was destroyed, and the bony part of the eustachian tube was ground to the cartilage part of the eustachian tube. Under the mi croscope, destruction of vertical segment of carotid artery canal was confirmed, and the pulsation of the carotid artery could be seen. The facial nerve and parotid gland were exposed. For the lesions in the parapharyngeal space could not be shown clearly by microscope, then the space was examined by endoscopy (0degree and 30-degree). Meticulous dissection between the mass capsule and surrounding tissues was performed under endoscopic magnified visualization. On the medial side, the carotid artery sheath was identi fied and the mass capsule was separated carefully from the vital struc tures of the carotid artery sheath from the top to the bottom. On the lateral side, the mass was dissected from the fascia of medial pterygoid muscle. At last, a 30-degree endoscope showed a niche-like structure consisted of hair, skin and cartilage, it was located just before the tip of the styloid process at the bottom of prestyloid parapharyngeal space (Fig. 2B). The main point of endoscope surgery was to identify the in ternal carotid artery as early as possible and then carefully separate tumor along the surface of the carotid sheath. After completely removing neoplasm, the pedicled temporal mus culoperiosteal flap was inserted into the parapharyngeal cavity. Fascia musculus temporalis was placed on the surface of the stape. The mea toplasty was made after excision of concha cartilage.
4. Discussion Dermoid is rare in the middle ear cleft. Because of its slow-growing nature, it usually remains symptom-free until it is large enough to involve the surrounding structures, which makes it usually difficult to access during surgery [1]. In this study, we performed four cases of such lesion which were successfully removed through combined-microscopy/endoscopy approach achieving a satisfying operative field and adequate operative space without further re currences. What’s more, the invasiveness of surgery was limited through microscopic/endoscopic resection avoiding transcervical approach. As mentioned above, the aetiology of dermoid is considered to be associated with the aberrant embryologic development, which makes it possible to be relatively common in paediatric patients. Three out of the four cases we reported were infants, while one was adolescent female. Our finding is in line with previous reports [8–12]. The clinical symp toms were relatively mild, such as intermittent otorrhea, mild conduc tive hearing loss and so on. It could be explained by the latent development of the disease. It only came to symptomatic with expansion to parapharyngeal space and eustachian tube. Symptoms worsen when parapharyngeal space infection occurs, as case 1. Histopathologically, dermoid is comprised of ectodermal and mesodermal derivatives [13]. The mesodermal components often include fat, cartilage and muscle, while the ectodermal layer is comprised of a keratinizing squamous epithelial layer with adnexal structures, such as hair follicles. In the previous literature, terms such as dermoid [3,5], dermoid cyst [1,14], hairy polyps [15], hamartomas [9, 16], teratoma [8], and cholesteatoma have been used interchangeably 4
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Fig. 4. Surgical findings in Case 2. An Endoscopic view of the lesion, showing a polypoid, skin-covered, hairy mass within the eustachian tube. B Endoscopic view of the lesion after partly resection of the mass, the pedicle (origin) of the mass is at the pharyngeal orifice of eustachian tube (asterisk), the nasopharynx can be seen through the dilated eustachian tube (arrow).
Fig. 5. Characteristically pathological image (100× magnified) in Case 1 (A) and 4 (B), manifesting skin (white arrow), sebaceous glands (black arrow), cartilage (asterisk), adipose tissue (triangular) and hair follicles (diamond).
to describe the dermoid lesion in the middle ear and eustachian tube. According to the 2016 WHO classification of tumours of the central nervous system [17], teratoma is defined as a germ cell tumour composed of somatic tissues derived from two or three of the germ layers (i.e. the ectoderm, endoderm, and mesoderm). Thus, dermoid can be regarded as to be a bigeminal teratomas derived from both ectodermal and mesodermal elements. Based on the literature review and our cases, we suggest dermoid in the middle ear and Eustachian tube can be classified into 2 subtypes according to gross appearance: (1) Dermoid cyst, which presents as a cystic mass without a stalk, and which has a lumen lined by keratinized and stratified squamous epithelium and containing keratin and hair in it, just as in our case 1. (2) Hairy polyp, which appear as a sausage-like polyp with a pedicle, the cover is skin and hair, and the inside is fat, cartilage and muscle, just as our case 2,3,4. According to article reviews [18–20] the salivary gland tissue might be found in some cases, just as in our cases 4. In our cases, the stalk of hairy polyps is at the Eustachian tube, which is lined with respiratory ciliated mucosa, thus the squamous-columnar junction can be found at the stalk. The two subtypes of dermoid can have different imaging signs, especially on MRI. Dermoid cyst in the middle ear cleft may have similar imaging features with cholesteatoma, thus preoperative diagnose of the cholesteatoma was made in case 1.Hairy polyps in the middle ear and Eustachian tube may show occlusion inflammation signs in the mastoid and middle ear, enlargement of bony part of Eustachian tube, and the mass itself may show similar imaging characteristics as hairy polyps in the oral-nasopharynx. Upon MRI scan, a hairy polyp in the oralnasopharynx is usually shown as polyp-like, well-circumscribed, pedunculated mass with a fat density or signal which can be approved by fat-suppression technique [21–24]. The mass in oral-nasopharynx is usually not enhanced and the stalk of it is clearly identified on MRI imaging. Otherwise, when the hairy polyp was located in the middle ear and Eustachian tube, the stalk was not easily identified and the surface might be enhanced due to inflammation on MRI imaging.
According to the literature, dermoid in the middle ear cleft usually appeared as hairy polyps on the gross appearance. The dermoid appearing as cyst-like mass in the middle ear was extremely rare, not well-documented in the literature. The Eustachian tube might be the most common attachment site of the dermoid in the middle ear cleft. Three of our cases originated from Eustachian tube, the other one originated from the prestyloid parapharyngeal space. The surgical excision is the best solution to these lesions. Surgical routes described in the literature are classified as transoral, transnasal, transtympanic, transmastoid approach, or combined transmastoid/ transcervical approach [4,5,10,11,25]. The use of endoscopy is extremely beneficial for better preservations of the important structures such as the ICA and the facial nerve [26]. For the dermoid mass in the nasopharynx arising from the eustachian tube, which usually presents as a hairy polyp with a stalk near the pharyngeal ostium in the eustachian tube, the endoscopic transoral or transnasal approach is the first choice [27,28]. If its origination in the eustachian tube could not be detected accurately by transnasal endo scope, part of tumour in the eustachian tube may be spared during surgery. In that case, an addition surgery would be needed to further remove the residual tumour. For those whose principal part locating in the middle ear or in the Eustachian tube, transmastoid approach is a good choice. In 1992, Vrabec [29] described a dermoid mass involving the middle ear and eustachian tube. In that case, after the tumor was delivered from the eustachian tube through the middle ear, a rigid telescope was passed from the middle ear to the nasopharynx to ensure complete tumor removal. In recent years, thanks to the development of endoscopy and visualization system, the exact origin of the tumour in the dilated eustachian tube or parapharyngeal space and the relationship to the 5
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Table 1 Demographics and baseline disease characteristics. Case
Age
Sex
Side
Otorrhea
Hearing loss
ICA
Eustachian tube
Parapharyngeal space
Follow-up
1 2 3 4
16Y 1Y 11 M 7M
F M F F
R R L R
2M 8M 1M 4M
Mild Mild Mild-to-moderate Mild-to-moderate
Yes Yes No No
Yes Yes Yes Yes
Yes Yes Yes No
15 M 10Y 5Y 6M
ICA, internal carotid artery. Table 2 Clinical characteristics of 4 cases. Case
Subtype
Tumor involvement
Mass origination
Gross appearance
Pathological examination
1
Middle ear,ET, parapharyngeal space Middle ear,ET
No stalk was found.
Cyst with skin-covered cavity Hairy polyps with a stalk
skin, fat, cartilage
2
Dermoid cyst Hairy polyps
skin, fat, cartilage, fibrous tissues
3
Hair polyps
Middle ear,ET
Hairy polyps with a stalk
skin, fat, cartilage, fibrous tissues
4
Hairy polyps
Antrum, Middle ear,ET
Hairy polyps with a stalk
skin, fat, cartilage, fibrous tissues, glandular tissue
Stalk in the cartilage part of ET Stalk in the cartilage part of ET Stalk in the cartilage part of ET
ET, Eustachian tube.
Ethics statement
carotid canal could be seen clearly. The deep location of the eustachian tube and parapharyngeal space, the proximity of internal carotid artery characterizes the treatment of these lesions as particularly challenging. In our experience, at the beginning, we finished the mastoidectomy under microscope and remove the bony barrier around the bony portion of the eustachian tube and the tympanic part of the temporal bone. If necessary, the anterior wall of the external auditory canal should be removed and the mandible was retracted anteriorly. Then we used the endoscope to examine and removed the tumour in the eustachian tube or parapharyngeal space. The surgeon should keep in mind that the masses might arise closely to the carotid artery and erode the vertical part of carotid canal. As in our cases, there was erosion to the vertical canal in two of them. For the carotid artery in this area is vulnerable, the mass should be removed gently and carefully around the carotid artery. For the hairy polyps usually have a pedicle, it is important to identified the attachment site. After the pedicle was sectioned, the mass can be pulled out through the protympanium or through oro-nasopharynx. As for the dermoid of the ear or eustachian tube, which invading to the parapharyngeal space, only 2 cases were found in the English liter ature [5]. It is reported to be removed through transmastoid approach combined with transcervical or transparotid neck dissection was re ported. In our case 1, the mass was massive, invading into the prestyloid compartment, expanding to the deep lobe of the parotid and beneath the tip of the styloid process. In this case, surgical treatment is very chal lenging. We use the transmastoid approach combined with endoscope, avoiding transcervical parotidectomy. As far as we know, it is firstly reported to successfully treat such lesion involving the parapharyngeal space with endoscopic-combined transmastoid approach.
This retrospective case series was approved by the Review Board of Beijing TongRen Hospital. As this was a case series, consent was exempt. Declaration of competing interest All authors declare no financial or commercial conflicts of interest. Acknowledgement Not applicable. References [1] H.S. Al-Muhaimeed, H.Y. Abdelwahed, E.A. Elgamal, G.M. Alokby, A.M. Binnasser, M.M. Ashraf, Extradural dermoid cyst of mastoid bone: a case report, Case Rep Otolaryngol (2012) 548340, https://doi.org/10.1155/2012/548340, 2012. [2] Y. Cho, D.H. Lee, Clinical characteristics of idiopathic epidermoid and dermoid cysts of the ear, J Audiol Otol 21 (2) (2017) 77–80, https://doi.org/10.7874/ jao.2017.21.2.77. [3] B.R. Campbell, R.J. Yawn, B.P. O’Connell, A. Rivas, Dermoid tumor of the middle ear: a case report and review of the literature, Otolaryngology Case Reports 4 (2017) 18–20, https://doi.org/10.1016/j.xocr.2017.08.003. [4] S. Nalavenkata, C. Meller, M. Forer, N.P. Patel, Dermoid cysts of the Eustachian tube: a transnasal excision, Int. J. Pediatr. Otorhinolaryngol. 77 (4) (2013) 588–593, https://doi.org/10.1016/j.ijporl.2012.12.026. [5] S.S. Kollias, W.S. Ball Jr., E.C. Prenger, C.M. Myers 3rd, Dermoids of the eustachian tube: CT and MR findings with histologic correlation, AJNR American journal of neuroradiology 16 (4) (1995) 663–668. [6] T. Minatogawa, M.N. Node, I. Fukuda, T. Kumoi, Dermoid cyst in the middle ear, J. Laryngol. Otol. 107 (4) (1993) 335–338, https://doi.org/10.1017/ s0022215100122960. [7] L. Presutti, M. Alicandri-Ciufelli, A. Rubini, F.M. Gioacchini, D. Marchioni, Combined lateral microscopic/endoscopic approaches to petrous apex lesions: pilot clinical experiences, Ann. Otol. Rhinol. Laryngol. 123 (8) (2014) 550–559, https:// doi.org/10.1177/0003489414525342. [8] A. Alqurashi, E. Bakry, M. Straube, C.H. Rickert, P. Mir-Salim, Mature teratoma of the temporal bone in 3.5-month-old baby girl, Case Reports in Otolaryngology 2015 (2015) 1–3, https://doi.org/10.1155/2015/372089. [9] S. Baget, A. François, J. Andrieu-Guitrancourt, J.P. Marie, D. Dehesdin, Hamartoma of the middle ear: a case study, Int. J. Pediatr. Otorhinolaryngol. 67 (3) (2003) 287–291, https://doi.org/10.1016/s0165-5876(02)00376-2. [10] J.L. Wang, Z.H. Hou, L. Chen, J. Yuan, S.M. Yang, Combined application of otoendoscopes and nasal endoscopes for resection of dermoid tumor in eustachian tube, Acta Otolaryngol. 131 (2) (2011) 221–224, https://doi.org/10.3109/ 00016489.2010.504738. [11] G. Cantarella, M. Gaffuri, L. Pugni, L. Pignataro, F. Mosca, Severe respiratory distress at birth caused by a hairy polyp of the Eustachian tube: transoral endoscopy-guided treatment, Congenital. Anom. 55 (3) (2015) 158–160, https:// doi.org/10.1111/cga.12100.
5. Conclusions In conclusion, our study showed that dermoid of the middle ear usually appear in children of early ages involving the eustachian tube. The dermoid may appear as hairy polyps or dermoid cyst. The dermoid may originated from eustachian tube or parapharyngeal space. Surgical resection with assistance of endoscope has satisfying outcome for these cases. Funding Not applicable.
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International Journal of Pediatric Otorhinolaryngology xxx (xxxx) xxx [21] S.C. Kochanski, E.M. Burton, F.G. Seidel, L.R. Chanin, S. Hensley, J.D. Acker, Neonatal nasopharyngeal hairy polyp: CT and MR appearance, J. Comput. Assist. Tomogr. 14 (6) (1990) 1000–1001, https://doi.org/10.1097/00004728199011000-00027. [22] L. Cerezal, C. Morales, F. Abascal, A. Canga, J. Gomez, M. Bustamante, Magnetic resonance features of nasopharyngeal teratoma (hairy polyp) in an adult, Ann. Otol. Rhinol. Laryngol. 107 (11 Pt 1) (1998) 987–990, https://doi.org/10.1177/ 000348949810701115. [23] J.K. Kraft, L.C. Knight, C. Cullinane, US and MRI of a pharyngeal hairy polyp with pathological correlation, Pediatr. Radiol. 41 (9) (2011) 1208–1211, https://doi. org/10.1007/s00247-011-2064-9. [24] M. Sheng, Y. Mi, F. Gao, J. Liang, H. Zhou, Imaging features of pharyngeal hairy polyps in infants, Oral Radiol. (2020), https://doi.org/10.1007/s11282-02000430-5. [25] J.L. Roh, Transoral endoscopic resection of a nasopharyngeal hairy polyp, Int. J. Pediatr. Otorhinolaryngol. 68 (8) (2004) 1087–1090, https://doi.org/10.1016/j. ijporl.2004.03.005. [26] H. Kojima, Y. Tanaka, Y. Yaguchi, H. Miyazaki, S. Murakami, H. Moriyama, Endoscope-assisted surgery via the middle cranial fossa approach for a petrous cholesteatoma, Auris Nasus Larynx 35 (4) (2008) 469–474, https://doi.org/ 10.1016/j.anl.2007.09.010. [27] J. Wu, J. Schulte, C. Yang, F. Baroody, D.T. Ginat, Hairy polyp of the nasopharynx arising from the eustachian tube, Head and Neck Pathology 10 (2) (2015) 213–216, https://doi.org/10.1007/s12105-015-0632-2. [28] N. Agrawal, D. Kanabar, G.A. Morrison, Combined transoral and nasendoscopic resection of an eustachian tube hairy polyp causing neonatal respiratory distress, Am. J. Otolaryngol. 30 (5) (2009) 343–346, https://doi.org/10.1016/j. amjoto.2008.06.001. [29] J.T. Vrabec, M.K. Schwaber, Dermoid tumor of the middle ear: case report and literature review, Am. J. Otol. 13 (6) (1992) 580–581.
[12] D. Lepera, L. Volpi, F. De Bernardi, S.A. Shawkat, L. Cimetti, M. Bignami, P. Castelnuovo, Endoscopic transnasal resection of Eustachian-tube dermoid in a new-born infant, Auris Nasus Larynx 42 (3) (2015) 235–240, https://doi.org/ 10.1016/j.anl.2014.10.015. [13] M. Dutta, S. Roy, S. Ghatak, Naso-oropharyngeal choristoma (hairy polyps): an overview and current update on presentation, management, origin and related controversies, Eur. Arch. Oto-Rhino-Laryngol. 272 (5) (2015) 1047–1059, https:// doi.org/10.1007/s00405-014-3050-2. [14] O.C. Luz, L.C. Raquel, S.D.O. Marimar, D.M. Carola, P.L. Carolina, R.M.J.P. D. Ramon, Dermoid cysts: a report of 75 pediatric patients, Pediatr. Dermatol. 30 (6) (2013) 706–711. [15] P. Walker, Dilated Eustachian tube orifice after endoscopic removal of hairy polyp, Otolaryngol. Head Neck Surg. 139 (1) (2008) 162–163, https://doi.org/10.1016/j. otohns.2007.07.032. [16] A.R. Hulsmann, N. de Bont, J.C. den Hollander, J.A. Borgstein, Hamartomas of the oro- and nasopharyngeal cavity in infancy: two cases and a short review, Eur. J. Pediatr. 168 (8) (2009) 999–1001, https://doi.org/10.1007/s00431-008-0865-0. [17] D.N. Louis, A. Perry, G. Reifenberger, A. von Deimling, D. Figarella-Branger, W. K. Cavenee, H. Ohgaki, O.D. Wiestler, P. Kleihues, D.W. Ellison, The 2016 world health organization classification of tumors of the central nervous system: a summary, Acta Neuropathol. 131 (6) (2016) 803–820, https://doi.org/10.1007/ s00401-016-1545-1. [18] P.E. Farris, W.L. Meyerhoff, F. Vuitch, Congenital dermoid cyst of the middle ear, Skull Base Surg. 8 (2) (1998) 77–80, https://doi.org/10.1055/s-2008-1058579. [19] C.G. Gourin, R.A. Sofferman, Dermoid of the eustachian tube, Otolaryngol. Head Neck Surg. 120 (5) (1999) 772–775, https://doi.org/10.1053/hn.1999.v120. a86475. [20] B.M. Cone, M. Taweevisit, S. Shenoda, S. Sobol, E. Schemankewitz, B.M. Shehata, Pharyngeal hairy polyps: five new cases and review of the literature, Fetal Pediatr. Pathol. 31 (3) (2012) 184–189, https://doi.org/10.3109/15513815.2011.648722.
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