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Parapharyngeal space tumors: 61 case reviews
Int. J. Oral Maxillofac. Surg. 2010; 39: 983–989 doi:10.1016/j.ijom.2010.06.005, available online at http://www.sciencedirect.com
Clinical Paper Clinical Pathology
Parapharyngeal space tumors: 61 case reviews M. V. Dimitrijevic, S. D. Jesic, A. A. Mikic, N. A. Arsovic, N. R. Tomanovic: Parapharyngeal space tumors: 61 case reviews. Int. J. Oral Maxillofac. Surg. 2010; 39: 983–989. # 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Parapharyngeal tumors account for 0.5% of head and neck tumors. They are difficult to diagnose because they have few symptoms and are surgically inaccessible. This retrospective study included 61 patients with parapharyngeal space tumors, treated in the last 20 years. The data, obtained from the medical records, included symptoms and clinical signs, diagnostic procedures, surgical approach, postoperative complications and histopathological findings. The most common symptoms were dysphagia, foreign body sensation, pain, and symptomfree patients. For precise tumor localization and its relation to adjacent structures, computerized tomography, magnetic resonance imaging and contrast angiography were used. All the patients were treated surgically. The commonest surgical approach was transcervical, followed by transoral and combined transcervical– transoral. Histopathological examination verified that the origin of these tumors was most frequently salivary or neurogenic.
Tumors of the parapharyngeal space (PPS) are rare, accounting for 0.5% of all head and neck tumors. PPS tumors may be primary, metastatic or a direct extension of tumors from the adjacent spaces. The frequency of benign and malignant tumors is about 80% and 20%, respectively. Most of them originate from the salivary gland (40–50%), followed by a neurogenic etiology and the remainder are a broad spectrum of miscellaneous tumors4,5,13,19,25. The PPS is a lateral pharyngeal region. It is divided by muscular aponeurotic partition into an anterior (prestyloid) muscular compartment and a posterior (poststyloid) neurovascular compartment4,9,13,18,19,25. PPS tumors may be undetected for a long time, because they are not linked to symptoms. They are often presented as an asymptomatic growth and may be detected 0901-5027/100983 + 07 $36.00/0
by regular checkup or as an accidental finding when scanning for another reason2. Clinically, they are most frequently noted as a growth pushing the lateral wall of the oropharynx medially or a growth on the neck under the edge of the mandible angle. The symptoms are manifested when the tumor becomes larger than 2.5– 3 cm13,19,25. The symptoms of PPS tumors are multiple and relate to the prestyloid–poststyloid localization, they include frequent foreign body sensation, difficult deglutition, otological symptoms and hoarseness. Clinical manifestations of PPS tumors are a mass in the oropharynx, a neck mass, cranial nerve deficit and Eustachian tube obstruction2,5,13,19,25. Imaging is crucial for the assessment of PPS tumors. Computed tomography (CT) with contrast medium, magnetic reso-
M. V. Dimitrijevic1, S. D. Jesic1, A. A. Mikic1, N. A. Arsovic1, N. R. Tomanovic2 1 Clinical Center of Serbia, Clinic of Otorhinolaryngology and Maxillofacial Surgery, Belgrade, Serbia and University of Belgrade, School of Medicine, Belgrade, Serbia; 2Institute of Pathology, University of Belgrade, School of Medicine, Belgrade, Serbia
Key words: parapharyngeal tumors; symptoms; clinical signs; surgical approach; histopathology. Accepted for publication 2 June 2010 Available online 16 July 2010
nance (MR) and contrast angiography, in selected cases, are essential for diagnosis. Contrast CT is an effective imaging examination. MR is better than CT because it provides useful information on tumor localization and extent, and distinguishes tumors of the deep lobe, neurogenic lesions or intravagal paraganglioma or carotid body tumors and their relations with the internal carotid artery and adjacent structures5,9,13,16,19,22,25. Angiography is recommended if paragangliomas or the involvement of the carotid artery is suspected5,8,9,13,19. Surgery is performed on the basis of information provided by these diagnostic modalities. Surgery of PPS tumors requires adequate exposure to identify and protect the anatomic vital structures. Several surgical approaches to PPS are described including transcervical,
# 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
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transcervical–transparotid, transcervical– transmandibular and transoral approaches, which are usually performed in these cases. All approaches have indications, advantages and disadvantages. The most common parameter for selecting a surgical approach is maximal exposure for complete tumor removal and preservation of the anatomic structures while minimizing functional and esthetic loss5,9,13,16,18,19,25. Materials and methods
This retrospective study included patients who had been diagnosed with PPS tumors and surgically treated from 1988 to 2007. The medical records were evaluated and analyzed. The data obtained was based on medical records, and included symptoms and clinical signs, diagnostic procedures, surgical approach and histopathological findings. This study involved 61 patients; all of whom were operated on by the same surgical team. All patients were clinically evaluated in detail. Neurological evaluation of the cranial nerves was also carried out. An audiogram was performed in cases with hearing disturbances. The preoperative imaging diagnostics used were contrast CT and, recently, multi-slice CT (MSCT) and MR. In cases with a high suspicion of vascular tumor, angiography was applied. Analysis of the imaging methods revealed that the most important parameters determined were: localization of pre- or poststyloid tumor, relation to parotid gland, relation to major blood vessels and tissue characteristics of the tumors. All patients in this study were treated surgically. The surgical approach was dictated by the localization of the tumor, its dimensions, relation to anatomic structures (carotid artery, jugular vein, cranial nerves) and suspicion of malignancy. Follow-up was carried out through clinical examination, chest radiographs, ultrasound of the neck, and CT scan of the head and neck where indicated (for all malignant tumors and for benign tumors with capsule rupture or tumor spillage). The median follow-up was 24 months. Data obtained from analysis of the medical history were statistically processed (x2-test). The objective of this study was to describe and analyze the symptoms and clinical signs of PPS tumors, the diagnostic procedures, surgical approach and histopathological findings. Results
This was a retrospective analysis of PPS tumors in 61 patients (32 males; 29
Table 1. Incidence and frequency of symptoms. Total
Symptoms 1. 2. 3. 4. 5. 6. 7. 8. 9.
Dysphagia* Foreign body sensation Pain Symptom free Otological symptoms Hoarseness Dyspnea Limited mouth opening Symptoms of catecholamine excess
Total
N
%
29 17 14 14 5 2 1 1 0
35 21 17 17 6 2 1 1 0.00
83
100.00
x2-test; p < 0.01. The asterisk represents the most significant symptom. Table 2. Incidence and frequency of clinical signs. Total
Signs N
%
1. Oropharyngeal mass* 2. Neck mass 3. Parotid mass 4. CN deficit 5. Pain on palpation 6. Unilateral Eustachian tube dysfunction 7. Obstructive sleep apnea 8. Horner Syndrome 9. Trismus 10. Catecholamine excess
46 20 12 6 2 2 1 1 0 0
51 22 14 7 2 2 1 1 0.00 0.00
Total
90
100.00
x2-test; p < 0.01. The asterisk represents the most significant clinical sign.
females) treated primarily by surgery, whose mean age was 47 years (range 8– 76 years). Patients who had undergone surgery for PPS tumors in other institutions and patients with other tumors were excluded from the study. The incidence and frequency of symptoms were analyzed (Table 1). The most frequent symptoms were dysphagia (35%), foreign body sensation (21%) and pain (17%) (Table 1). The incidence of asymptomatic patients was highly significant; in 14 patients an asymptomatic growth was detected during a routine checkup or accidentally while scanning for another reason. The difference between the incidence of three symp-
toms presented in Table 1 and other symptoms was highly significant (x2-test, Yates’ correction, x2 = 27.44, DF = 5, p < 0.01). The symptom that was not manifested was not considered. The most frequent clinical signs were oropharyngeal mass (51%), neck mass (22%) and parotid mass (41%) (Table 2). More frequent incidence of the first three signs from Table 2 was highly significant (x2 = 61.77, DF = 4, p < 0.01). CT, MR and angiography were the diagnostic methods used. The frequency of CT and MR use was 70% (47 patients) and 21% (14 patients), respectively.
Table 3. Surgical approach to the tumors. Total
Surgical approach N
%
1. External 1. Transcervical 16 2. Transcervical–transparotid 19 3. Transcervical–transmandibular 3 2. Transoral 3. Combination (transcervical + transoral)
38
62
13 10
21 17
Total
61
2
x -test; p < 0.01.
100.00
Parapharyngeal space tumors Angiography was applied in 9% (6 patients). Data processing using the x2test showed a highly significant difference in the number of uses of CT compared with other diagnostic techniques (x2 = 42.29, DF = 2, p < 0.01). The surgical approach to the tumors is given in Table 3. An external approach was most frequently used (transcervical, transcervical–transparotid, transcervical– transmandibular) in 62% (38), the transoral approach in 21% and combined approaches in 16%. The combined approach comprised a transcervical and intraoral approach without mandibular osteotomy and it was applied in larger tumors. The transcervical–transmandibular approach with mandibular osteotomy in the parasymphysial region was used in 3 cases with malignant tumors. Planned tracheotomy was performed in patients undergoing the transmandibular approach and in one patient undergoing the combined approach. One patient had a nonplanned tracheotomy during wound management for a postoperative complication (hemorrhage). Ex tempore tumor analysis was carried out in 12 patients suspected of malignancy on the basis of CT or MR
findings. The facial nerve was resected in one patient, which was not reconstructed due to advanced disease. The difference of the application of the external surgical approaches and other surgical approaches was significant (x2 = 16.75, DF = 2, p < 0.01). Complications of surgical treatment were reported in 15 patients. Temporary paresis or paralysis of n. facialis (predominantly the marginal branch) was observed in 6 patients. Frey’s syndrome was seen in one patient but it gradually faded, unilateral paralysis of the vocal cords and hoarseness were noted in two patients, weakness of the hypoglossus in one patient as well as dysphagia in another, bleeding in one patient (within 24 h following the surgery); in addition, first bite syndrome was reported in two patients and trismus in one patient. The results of histopathological analysis are presented in Table 4. The incidence of salivary tumors was the highest (43%), the incidence of neurogenic tumors was 29% and that of other tumors was 28%. The incidence of salivary tumors and other types of tumors was not significantly different. Pleomorphic adenoma accounted
Table 4. Results of histopathological analysis. Total
Histopathology
%
N
%
Salivary Pleomorphic adenoma Basal cell adenoma Adenocarcinoma
21 2 3
81 8 11
Total
26
100.00
Neurogenic Neurilemoma/schwannoma Neurofibroma Ganglioneuroblastoma Paraganglioma
13 1 1 3
72 5.5 5.5 17
Total
18
100.00
1 1 1
6 6 6
3 2 3 1 2 1 1 1
18 12 18 6 12 6 6 6
Miscellaneous Metastasis UCNT Metastasis of neuroendocrine carcinoma Metastasis of papillary thyroid carcinoma Lymphoma non-Hodgkin Sarcoma Squamous cell carcinoma Chordoma Benign cyst Benign lymph node hyperplasia Hemangioma Lipoma Total
17
100.00
Total
61
100.00
2
x -test; p < 0.01.
43
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for 21 tumors and neurilemoma for 13; together they accounted for over a half of all PPS tumors. The frequency of benign and malignant tumors was 74% and 26%, respectively. The most frequent PPS tumors were adenocarcinoma, squamous cell carcinoma and non-Hodgkin’s lymphoma, accounting for more than half of malignant PPS tumors. The frequency of benign in relation to malignant tumors was significant (x2 = 13.78, DF = 1, p < 0.01). The median follow-up was 24 months. 45 patients (74%) had a benign tumor. Only one case from this group had a recurrence of the tumor, which was diagnosed by CT, 7 months after the primary operation (histopathology verified that the cyst had been perforated during the primary intervention). In patients with benign tumors with capsule rupture or tumor spill regular controls included a CT 1 year after surgery. Malignant tumors accounted for 26% (16 patients). Postoperative radiotherapy was applied in 5 patients, and combined chemo-radiotherapy in 10 patients. The patient with a papillary cancer metastasis was subsequently treated surgically with a total thyroidectomy and neck dissection and he continued with his controls in another institution. The patients with malignant tumors had regular controls that included clinical examination, lung X-ray and CT (1 month after completing radiotherapy and patients who received postoperative chemo-radiotherapy had a CT scan after finishing every third cycle of the chemotherapy). In this group of patients, five were disease-free, seven had a disease and three died of malignant parapharyngeal tumor in the follow-up period. Discussion
29
28
PPS tumors, although rare, are always a challenge for surgeons because of their complex anatomy, scarce symptomatology and difficulties in diagnosis. The purpose of this study was to evaluate the symptoms and clinical signs, diagnostic procedures, surgical approach and histopathological findings of 61 patients with tumors of the PPS. In this series, most of the PPS tumors were benign (74%, compared with 26% malignant), which is comparable with the findings of other studies ranging from 70% to 82% benign and 18–30% malignant2,4,13,18,19,25. The most common PPS tumors originate from the salivary gland tissue of the deep parotid lobe or salivary tissue or ectodermic residua associated with the cranial nerves and the cervical
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Fig. 1. Tumor of the parapharyngeal space.
sympathetic chain or from the glomus body19. Tumors with a salivary gland etiology were the most frequent (30– 48%), followed by tumors of neurogenic origin (20–32%), which was comparable with other studies2,4,13,18,19,25. A smaller number of studies claim neurogenic tumors are the most frequent, accounting for 57%2,5. Paragangliomas were reported in studies by BATSAKIS and SNEIGE4 in 11%, by MALONE et al.18 in 12%, by CARRAU et al.5 in 40%; their incidence in this study was 5%. The most frequent malignant tumors in this study were adenocarcinoma, non-Hodgkin’s lymphoma, squamous cell carcinoma and metastatic lesions. Other studies described mucoepidermoid carcinoma and metastatic disease18, adenoid cystic carcinoma25 salivary malignancies and lymphoreticular lesions4, malignancy originating from neural tissue2,5 mucoepidermal carcinoma, adenoid cystic carcinoma13 and the rarely seen ganglioneuroblastoma7, and myofibroblastic sarcoma23. Most studies failed to analyze thoroughly the symptomatology and clinical signs of PPS tumors; instead they were mentioned as tumors of scarce symptomatology with an existing growth on the neck or lateral pharyngeal wall. In a large number of patients the tumors were detected on regular checkups or examinations due to suspicion of other diseases2,11,13,19,25. This is why the authors made a detailed analysis of symptoms and clinical signs based on evaluation of the medical records. The most frequent symptoms reported in literature are: growth on the neck
[(Fig._2)TD$IG]
(46%), pain (20%), dysphagia (13%), and pharyngeal growth (9%)5,19. SAN21 reported dysphagia as a TORO et al. leading symptom. In the present study, 14 (17%) patients had no symptoms while the most often symptom was dysphagia, in 35% of cases, followed by foreign body sensation in 21% and pain in 17%.
Fig. 2. Axial view showing tumor of the PPS.
Clinical signs reported in the literature are: neck mass (53%), followed by pharyngeal mass (51%), and parotid mass (9%)5,13. In this study, the predominant signs were pharyngeal mass (51%), neck mass (22%) and parotid mass (13%) (Fig. 1). Analysis of the imaging methods revealed that the most important parameters were: localization of tumor preor poststyloid, size and extension, relation to the parotid gland, relation to the blood vessels and tissue characteristics of the tumors and fat planes. Imaging methods contributed the most to diagnosis. MR and CT imaging provide excellent PPS images19. Contrast CT is an effective imaging method. Many authors have reported the superiority of MR over CT because it ensures better soft tissue differentiation and the possibility of MR angiography and better identification of the carotid artery2,22. CT imaging, although less precise in soft tissue evaluation, better depicts the styloid process and bony erosions. Anterior displacement of the carotid artery and the internal jugular vein is suggestive for poststyloid tumors, mostly neurinomas while salivary lesions displace vessels posteriorly22. In prestyloid tumors, a preserved fat plane between the deep lobe of the parotid gland and the tumor is indicative of a separate tumor originating from the extraparotid minor
[(Fig._3)TD$IG]
Parapharyngeal space tumors
Fig. 3. Multi-slice CT showing tumor of the PPS.
salivary glands13. Most often, poststyloid space tumors are of neurogenic etiology, schwannomas and paragangliomas19. CT with contrast and MR imaging with gadolinium are often used together to provide complementary information, which allows the surgeon to delineate the size, precise localization and probable cause of these tumors9,17. In this study, CT (70%) was the predominant diagnostic method used, because of the time period covered (the past 20 years). CT scanning is generally used for differentiating prestyloid and [(Fig._4)TD$IG]poststyloid space tumors, determining
the size and extension of benign and malignant neoplasm, parotid or non-parotid, and, to a lesser degree, vascularization2,5,19 (Fig. 2). Recently, MSCT has been applied in three cases, which resulted in accurate tumor diagnosis, localization, size and determination of tumor relation to adjacent structures (Figs 3 and 4). In all cases suspected of paraganglioma, arteriography was indicated5,8,13,19. The PPS is a relatively inaccessible space for a surgeon due to the localization of the superficial parotid lobe, facial nerve, mandible, carotid artery and jugular
Fig. 4. Multi-slice CT showing tumor of the PPS.
987
vein. The origin of most PPS tumors is from the deep lobe or neurogenic, and they may be reached by a transcervical–transparotid or transcervical approach. Surgery is the method of choice for PPS tumor management5. The choice of approach should be dictated by tumor localization, size and its relation to the carotid artery and jugular vein as well as suspicion of malignancy and relation to the base of the skull. External transcervical approaches are preferred for better neurovascular control and surgical radicality13,16,25 A transcervical approach was used in 62% of the present cases; other authors have reported the use of this approach 60–87% of the time7,13. The transcervical approach is indicated for the removal of tumors originating from the minor salivary glands as well as for schwannommas and paragangliomas in the poststyloid space (40%13, 48%5 and 100%18) while in this study it was employed in 26%. The transcervical approach allows direct access to the PPS; removal of the tumor is often improved by excision of the submandibular gland, vessel ligation and dividing digastric, stylohyoid and styloglossal muscles and stylomandibular ligament and anterior dislocation of the mandible1,18,20,25 as used by the authors. The transcervical–transparotid approach is suitable for prestyloid tumors arising in the deep lobe of the parotid gland (46%3 and 11%5) presented in this study in 31% of patients. Parotidectomy incision is extended to the level of the greater cornu of the hyoid bone. This approach requires identification and preservation of the main trunk of the facial nerve. The transoral approach may be used in carefully selected cases2,9,11,16,19. According to the authors’ results, 13 (21%) patients operated on using this approach had their tumors removed completely and there was no recurrence. ALISON et al.2 applied this method in 13% of operated patients. Watertight closure provides uncomplicated healing. The postoperative nutrition of patients included a nasogastric tube (72 h). Many authors do not use this approach because of the risk of injuring the blood vessels and the possibility of total tumor extirpation5,13,25. The combined approach (transcervical and transoral) may be used for the removal of benign sizeable tumors without mandibular osteotomy, and it makes the stay shorter and reduces the possibility of sequelae in the authors’ experience in 17% and 4–39%, respectively2,16. Blood vessels were identified and secured with vascular loops in a non-constricting fash-
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ion. In these cases, a nasogastric tube was used for alimentation for 5 days. In all cases using the transmandibular approach, the airway should be secured with a tracheotomy5,19,25, which was carried out in three (5%) patients with the transcervical– transmandibular approach. This approach is used in rare cases (2–9% of the time2,13,19) and, according to the authors’ experience, it is indicated for malignant tumors5,19. Osteotomy was performed in the premolar region; the literature describes both single26 and double osteotomies3,13–15. In surgery of the PPS tumors, the surgeon must take care not to damage and rupture the capsule of the pleomorphic adenoma. In the authors’ experience, tracheotomy is not indicated often (in 7% of patients), and in 6–27% according to other authors5,18. In benign tumor accessibility, safety and completeness of resection direct the selection of approach. In malignant tumors, radicality of resection and options for reconstruction and rehabilitation and additional oncologic therapy are the factors defining the selection of the surgical approach. The authors consider that malignant tumors of this space always require additional therapy (radio and/or chemotherapy) in cases with high-degree malignant tumors, in indefinite or positive surgical margins5,13,16. In the literature, data on PPS tumor control are often incomplete, probably due to the small number of tumors and their variability. The frequency of benign tumor recurrence is low2,13,18,25, in this series only one recurrence was recorded. Many authors report that malignant PPS tumors have a poor prognosis2,13,16,18,25. Incision biopsy carries the risk of tumor dissemination, and is suggested in suspicion of malignant neoplasm5,25. Fine-needle aspiration biopsy (FNAB), guided or not, may contribute to the preoperative evaluation of PPS tumors, especially benign ones (90%)1,2,10,12,23,24. The role of FNAB in preoperative evaluation of patients with PPS tumors is unclear2,13. FNAB correlates with definite histopathological findings in 65%, and has as high as 87% sensitivity for detection of malignant diseases13. FNAB is helpful in evaluating these tumors, because tumor dissemination and injury of the major blood vessels can be avoided, when an open incision biopsy is contraindicated18. It is particularly recommended when lymphoma, metastatic lesions and other malignant neoplasms are suspected; it is not suggested in paragangliomas13,19. If imaging methods indicate a benign tumor, the authors’ opinion is that preoperative
biopsy is not necessary. The authors’ experience with FNAB and PPS tumors is very modest. In this study, ex tempore biopsy was performed in 12 patients suspected of malignancy, which was verified by FNAB in 8 patients. In this study, postoperative complications were reported in 25%, most commonly facial nerve lesions. Lesions of cranial nerves in patients with removed neurogenic tumors25 or malignant tumors and paragangliomas account for 30–48% of cases5,13,16,18. First bite syndrome is not a common complication6. Many sequelae of surgical treatment are transitory and a permanent deficit is present in 11%.5 In conclusion, it is most important to evaluate localization, diameter of PPS tumor and relation to neurovascular structures. The most frequent PPS tumors are salivary tumors (43%) and neurogenic tumors (29%). Malignant tumors were present 26% of the time. Imaging methods are essential for evaluating the PPS mass. CT and/or MR are necessary for deciding on the surgical approach. Complete surgical excision is considered the gold standard. External transcervical approaches are preferred. Preoperative biopsy is performed only if malignancy is suspected and non-surgical treatment or FNAB is given in all cases except suspected vascular tumors. Funding
None. Competing interests
None declared. Ethical approval
This study complies with the guidelines laid down in the Declaration of Helsinki; Recommendations guiding physicians in biomedical research involving human subjects (adopted by the 18th WMA, amended by the 29th WMA, the 35th WMA and the 41st WMA). This study has been approved by the ethical committee of the Clinical Centre of Serbia, and the subjects involved gave informed consent for their inclusion in the study. References 1. Abemayor E, Lufkin R. Enhancing access to the parapharyngeal space. Laryngoscope 2002: 112: 757–759. 2. Alison R, Waal IVD, Snow G. Parapharyngeal tumors—a review of 23 cases. Otolaryngology 1989: 199–203.
3. Attia El. Bentley KC, Head T, Mulder D. A new external approach of the pterygomaxillary fossa and parapharyngeal space. Head Neck Surg 1984: 6: 884–888. 4. Batsakis J, Sneige N. Parapharyngeal and retropharyngeal space diseases. Ann Otol Rhinol Laryngol 1989: 320– 321. 5. Carrau R, Myers E, Johnson J. Management of tumors arising in the parapharyngeal space. Laryngoscope 1990: 100: 583–589. 6. Chiu A, Cohen J, Burningham A, Andersen P, Davidson B. First bite syndrome: a complication of surgery involving the parapharyngeal space. Head Neck 2002: 10: 996–999. 7. Danosos D, Santos V, Ruffy M, Polisar I, Torno R. Ganglioneuroma of the parapharyngeal space. Bull NY Acad Med 1979: 56: 616–622. 8. Davidovic L, Ilic N, Dimitrijevic M, Ðukic V, Dzodic R. Surgical management of cervical paragangliomas. Am Surg 2008: 74: 1171–1176. 9. Ducic Y, Oxford L, Pontius AT. Transoral approach to the superomedial parapharyngeal space. Otolaryngol Head Neck Surg 2006: 134: 466–470. 10. Farag TY, Lin RF, Koch WM, Califano JA, Cummings CW, Farinola MA, Tufano RP. The role of preoperative CT-guided FNAB for parapharyngeal space tumors. Otolaryngol Head Neck Surg 2007: 136: 411–414. 11. Goodwin Jr W, Chandler J. Transoral excision of lateral parapharyngeal space tumors presenting intraorally. Laryngoscope 1988: 98: 266–270. 12. Handa U, Bal A, Mohan H, Dass A. Parapharyngeal paraganglioma: diagnosis on fine-needle aspiration. Am J Otolaryngol Head Neck Med Surg 2005: 26: 360–361. 13. Khafif A, Segev Y, Kaplan DM, Gil Y, Fliss DM. Surgical management of parapharyngeal space tumors—a 10 year review. Otolaryngol Head Neck Surg 2005: 132: 401–406. 14. Kolokythas A, Eisele D, El-Sayed I, Schmidt B. Mandibular osteotomies for access to select parapharyngeal space neoplasms. Head Neck 2009: 10: 102– 110. 15. Lazaridis N, Antoniades K. Double mandibular osteotomy with coronoidectomy for tumours in the parapharyngeal space. Br J Oral Maxillofac Surg 2003: 41: 142–146. 16. Luna-Ortiz K, Navarrete-Aleman EJ, Granados-Garcia M, HerreraGomez A. Primary parapharyngeal space tumors in a Mexican cancer center. Otolaryngol Head Neck Surg 2005: 132: 587–591. 17. Mafee MF, Venkatesan TK, Ameli N, Camras L, Friedman M. Tumors of parotid gland and parapharyngeal space-role of computed tomography and
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magnetic resonance imaging. Head Neck Surg 1996: 7: 348–357. Malone J, Agrawal A, Schuller D. Safety and efficacy of transcervical resection of parapharyngeal space neoplasms. Ann Otol Rhinol Laryngol 2001: 110: 1093–1098. Myers EN, Johnson JT, Curtin HG. Tumors of parapharyngeal space. 4th ed. In: Myers EN, Suen JY, Myers JN, Hanna EY, eds: Cancer of the Head and Neck, vol. 22. Philadelphia: WB Saunders 2003: 511–513. Orabi AA, Riad MA, O‘Regan MB. Stylomandibular tenotomy in the transcervical removal of large benign parapharyngeal tumours. Br J Oral Maxillofac Surg 2002: 40: 313–316. Santoro R, De Meester W, Coscarelli S, Polli G. Multiple neurinomas of
the parapharyngeal space. Eur Arch Otorhinolaryngol 1997: 254: 301–303. 22. Som PM, Sacher M, Stollman A, Biller H, Lawson W. Common tumors of the parapharyngeal space-imaging diagnosis. Head Neck Radiol 1988: 169: 81– 85. 23. Takahama A, Nascimento AG, Brum MC, Vargas PA, Lopes MA. Low-grade myofibroblastic sarcoma of the parapharyngeal space. Int J Oral Maxillofac Surg 2006: 35: 965–968. 24. Thomas G, Pandey M, Jayasree K, Pradeep V, Abraham EK, Iyoe EM, Krishnan Nair M. Parapharyngeal metastasis from papillary microcarcinoma of thyroid: report of a case diagnosed by peroral fine needle aspiration. Br J Oral Maxillofac Surg 2002: 40: 229– 231.
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25. Work PW, Hybels RL. A study of tumors of the parapharyngeal space. Laryngoscope 1974: 1748–1755. 26. Zitsch RP, Patenaude B, Tidmore T. An extraoral parapharyngeal space approach via vertical ramus osteotomy. Am J Otolaryngol Head Neck Surg 2007: 28: 330–333. Address: Milovan V. Dimitrijevic Clinic of Otorhinolaryngology and Maxillofacial Surgery Clinical Center of Serbia Pasterova 2 11000 Beograd Serbia Tel: +381 11 2643 694 Fax: +381 11 2643 694 E-mail: [email protected]
Clinical Paper Clinical Pathology
Parapharyngeal space tumors: 61 case reviews M. V. Dimitrijevic, S. D. Jesic, A. A. Mikic, N. A. Arsovic, N. R. Tomanovic: Parapharyngeal space tumors: 61 case reviews. Int. J. Oral Maxillofac. Surg. 2010; 39: 983–989. # 2010 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. Parapharyngeal tumors account for 0.5% of head and neck tumors. They are difficult to diagnose because they have few symptoms and are surgically inaccessible. This retrospective study included 61 patients with parapharyngeal space tumors, treated in the last 20 years. The data, obtained from the medical records, included symptoms and clinical signs, diagnostic procedures, surgical approach, postoperative complications and histopathological findings. The most common symptoms were dysphagia, foreign body sensation, pain, and symptomfree patients. For precise tumor localization and its relation to adjacent structures, computerized tomography, magnetic resonance imaging and contrast angiography were used. All the patients were treated surgically. The commonest surgical approach was transcervical, followed by transoral and combined transcervical– transoral. Histopathological examination verified that the origin of these tumors was most frequently salivary or neurogenic.
Tumors of the parapharyngeal space (PPS) are rare, accounting for 0.5% of all head and neck tumors. PPS tumors may be primary, metastatic or a direct extension of tumors from the adjacent spaces. The frequency of benign and malignant tumors is about 80% and 20%, respectively. Most of them originate from the salivary gland (40–50%), followed by a neurogenic etiology and the remainder are a broad spectrum of miscellaneous tumors4,5,13,19,25. The PPS is a lateral pharyngeal region. It is divided by muscular aponeurotic partition into an anterior (prestyloid) muscular compartment and a posterior (poststyloid) neurovascular compartment4,9,13,18,19,25. PPS tumors may be undetected for a long time, because they are not linked to symptoms. They are often presented as an asymptomatic growth and may be detected 0901-5027/100983 + 07 $36.00/0
by regular checkup or as an accidental finding when scanning for another reason2. Clinically, they are most frequently noted as a growth pushing the lateral wall of the oropharynx medially or a growth on the neck under the edge of the mandible angle. The symptoms are manifested when the tumor becomes larger than 2.5– 3 cm13,19,25. The symptoms of PPS tumors are multiple and relate to the prestyloid–poststyloid localization, they include frequent foreign body sensation, difficult deglutition, otological symptoms and hoarseness. Clinical manifestations of PPS tumors are a mass in the oropharynx, a neck mass, cranial nerve deficit and Eustachian tube obstruction2,5,13,19,25. Imaging is crucial for the assessment of PPS tumors. Computed tomography (CT) with contrast medium, magnetic reso-
M. V. Dimitrijevic1, S. D. Jesic1, A. A. Mikic1, N. A. Arsovic1, N. R. Tomanovic2 1 Clinical Center of Serbia, Clinic of Otorhinolaryngology and Maxillofacial Surgery, Belgrade, Serbia and University of Belgrade, School of Medicine, Belgrade, Serbia; 2Institute of Pathology, University of Belgrade, School of Medicine, Belgrade, Serbia
Key words: parapharyngeal tumors; symptoms; clinical signs; surgical approach; histopathology. Accepted for publication 2 June 2010 Available online 16 July 2010
nance (MR) and contrast angiography, in selected cases, are essential for diagnosis. Contrast CT is an effective imaging examination. MR is better than CT because it provides useful information on tumor localization and extent, and distinguishes tumors of the deep lobe, neurogenic lesions or intravagal paraganglioma or carotid body tumors and their relations with the internal carotid artery and adjacent structures5,9,13,16,19,22,25. Angiography is recommended if paragangliomas or the involvement of the carotid artery is suspected5,8,9,13,19. Surgery is performed on the basis of information provided by these diagnostic modalities. Surgery of PPS tumors requires adequate exposure to identify and protect the anatomic vital structures. Several surgical approaches to PPS are described including transcervical,
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transcervical–transparotid, transcervical– transmandibular and transoral approaches, which are usually performed in these cases. All approaches have indications, advantages and disadvantages. The most common parameter for selecting a surgical approach is maximal exposure for complete tumor removal and preservation of the anatomic structures while minimizing functional and esthetic loss5,9,13,16,18,19,25. Materials and methods
This retrospective study included patients who had been diagnosed with PPS tumors and surgically treated from 1988 to 2007. The medical records were evaluated and analyzed. The data obtained was based on medical records, and included symptoms and clinical signs, diagnostic procedures, surgical approach and histopathological findings. This study involved 61 patients; all of whom were operated on by the same surgical team. All patients were clinically evaluated in detail. Neurological evaluation of the cranial nerves was also carried out. An audiogram was performed in cases with hearing disturbances. The preoperative imaging diagnostics used were contrast CT and, recently, multi-slice CT (MSCT) and MR. In cases with a high suspicion of vascular tumor, angiography was applied. Analysis of the imaging methods revealed that the most important parameters determined were: localization of pre- or poststyloid tumor, relation to parotid gland, relation to major blood vessels and tissue characteristics of the tumors. All patients in this study were treated surgically. The surgical approach was dictated by the localization of the tumor, its dimensions, relation to anatomic structures (carotid artery, jugular vein, cranial nerves) and suspicion of malignancy. Follow-up was carried out through clinical examination, chest radiographs, ultrasound of the neck, and CT scan of the head and neck where indicated (for all malignant tumors and for benign tumors with capsule rupture or tumor spillage). The median follow-up was 24 months. Data obtained from analysis of the medical history were statistically processed (x2-test). The objective of this study was to describe and analyze the symptoms and clinical signs of PPS tumors, the diagnostic procedures, surgical approach and histopathological findings. Results
This was a retrospective analysis of PPS tumors in 61 patients (32 males; 29
Table 1. Incidence and frequency of symptoms. Total
Symptoms 1. 2. 3. 4. 5. 6. 7. 8. 9.
Dysphagia* Foreign body sensation Pain Symptom free Otological symptoms Hoarseness Dyspnea Limited mouth opening Symptoms of catecholamine excess
Total
N
%
29 17 14 14 5 2 1 1 0
35 21 17 17 6 2 1 1 0.00
83
100.00
x2-test; p < 0.01. The asterisk represents the most significant symptom. Table 2. Incidence and frequency of clinical signs. Total
Signs N
%
1. Oropharyngeal mass* 2. Neck mass 3. Parotid mass 4. CN deficit 5. Pain on palpation 6. Unilateral Eustachian tube dysfunction 7. Obstructive sleep apnea 8. Horner Syndrome 9. Trismus 10. Catecholamine excess
46 20 12 6 2 2 1 1 0 0
51 22 14 7 2 2 1 1 0.00 0.00
Total
90
100.00
x2-test; p < 0.01. The asterisk represents the most significant clinical sign.
females) treated primarily by surgery, whose mean age was 47 years (range 8– 76 years). Patients who had undergone surgery for PPS tumors in other institutions and patients with other tumors were excluded from the study. The incidence and frequency of symptoms were analyzed (Table 1). The most frequent symptoms were dysphagia (35%), foreign body sensation (21%) and pain (17%) (Table 1). The incidence of asymptomatic patients was highly significant; in 14 patients an asymptomatic growth was detected during a routine checkup or accidentally while scanning for another reason. The difference between the incidence of three symp-
toms presented in Table 1 and other symptoms was highly significant (x2-test, Yates’ correction, x2 = 27.44, DF = 5, p < 0.01). The symptom that was not manifested was not considered. The most frequent clinical signs were oropharyngeal mass (51%), neck mass (22%) and parotid mass (41%) (Table 2). More frequent incidence of the first three signs from Table 2 was highly significant (x2 = 61.77, DF = 4, p < 0.01). CT, MR and angiography were the diagnostic methods used. The frequency of CT and MR use was 70% (47 patients) and 21% (14 patients), respectively.
Table 3. Surgical approach to the tumors. Total
Surgical approach N
%
1. External 1. Transcervical 16 2. Transcervical–transparotid 19 3. Transcervical–transmandibular 3 2. Transoral 3. Combination (transcervical + transoral)
38
62
13 10
21 17
Total
61
2
x -test; p < 0.01.
100.00
Parapharyngeal space tumors Angiography was applied in 9% (6 patients). Data processing using the x2test showed a highly significant difference in the number of uses of CT compared with other diagnostic techniques (x2 = 42.29, DF = 2, p < 0.01). The surgical approach to the tumors is given in Table 3. An external approach was most frequently used (transcervical, transcervical–transparotid, transcervical– transmandibular) in 62% (38), the transoral approach in 21% and combined approaches in 16%. The combined approach comprised a transcervical and intraoral approach without mandibular osteotomy and it was applied in larger tumors. The transcervical–transmandibular approach with mandibular osteotomy in the parasymphysial region was used in 3 cases with malignant tumors. Planned tracheotomy was performed in patients undergoing the transmandibular approach and in one patient undergoing the combined approach. One patient had a nonplanned tracheotomy during wound management for a postoperative complication (hemorrhage). Ex tempore tumor analysis was carried out in 12 patients suspected of malignancy on the basis of CT or MR
findings. The facial nerve was resected in one patient, which was not reconstructed due to advanced disease. The difference of the application of the external surgical approaches and other surgical approaches was significant (x2 = 16.75, DF = 2, p < 0.01). Complications of surgical treatment were reported in 15 patients. Temporary paresis or paralysis of n. facialis (predominantly the marginal branch) was observed in 6 patients. Frey’s syndrome was seen in one patient but it gradually faded, unilateral paralysis of the vocal cords and hoarseness were noted in two patients, weakness of the hypoglossus in one patient as well as dysphagia in another, bleeding in one patient (within 24 h following the surgery); in addition, first bite syndrome was reported in two patients and trismus in one patient. The results of histopathological analysis are presented in Table 4. The incidence of salivary tumors was the highest (43%), the incidence of neurogenic tumors was 29% and that of other tumors was 28%. The incidence of salivary tumors and other types of tumors was not significantly different. Pleomorphic adenoma accounted
Table 4. Results of histopathological analysis. Total
Histopathology
%
N
%
Salivary Pleomorphic adenoma Basal cell adenoma Adenocarcinoma
21 2 3
81 8 11
Total
26
100.00
Neurogenic Neurilemoma/schwannoma Neurofibroma Ganglioneuroblastoma Paraganglioma
13 1 1 3
72 5.5 5.5 17
Total
18
100.00
1 1 1
6 6 6
3 2 3 1 2 1 1 1
18 12 18 6 12 6 6 6
Miscellaneous Metastasis UCNT Metastasis of neuroendocrine carcinoma Metastasis of papillary thyroid carcinoma Lymphoma non-Hodgkin Sarcoma Squamous cell carcinoma Chordoma Benign cyst Benign lymph node hyperplasia Hemangioma Lipoma Total
17
100.00
Total
61
100.00
2
x -test; p < 0.01.
43
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for 21 tumors and neurilemoma for 13; together they accounted for over a half of all PPS tumors. The frequency of benign and malignant tumors was 74% and 26%, respectively. The most frequent PPS tumors were adenocarcinoma, squamous cell carcinoma and non-Hodgkin’s lymphoma, accounting for more than half of malignant PPS tumors. The frequency of benign in relation to malignant tumors was significant (x2 = 13.78, DF = 1, p < 0.01). The median follow-up was 24 months. 45 patients (74%) had a benign tumor. Only one case from this group had a recurrence of the tumor, which was diagnosed by CT, 7 months after the primary operation (histopathology verified that the cyst had been perforated during the primary intervention). In patients with benign tumors with capsule rupture or tumor spill regular controls included a CT 1 year after surgery. Malignant tumors accounted for 26% (16 patients). Postoperative radiotherapy was applied in 5 patients, and combined chemo-radiotherapy in 10 patients. The patient with a papillary cancer metastasis was subsequently treated surgically with a total thyroidectomy and neck dissection and he continued with his controls in another institution. The patients with malignant tumors had regular controls that included clinical examination, lung X-ray and CT (1 month after completing radiotherapy and patients who received postoperative chemo-radiotherapy had a CT scan after finishing every third cycle of the chemotherapy). In this group of patients, five were disease-free, seven had a disease and three died of malignant parapharyngeal tumor in the follow-up period. Discussion
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PPS tumors, although rare, are always a challenge for surgeons because of their complex anatomy, scarce symptomatology and difficulties in diagnosis. The purpose of this study was to evaluate the symptoms and clinical signs, diagnostic procedures, surgical approach and histopathological findings of 61 patients with tumors of the PPS. In this series, most of the PPS tumors were benign (74%, compared with 26% malignant), which is comparable with the findings of other studies ranging from 70% to 82% benign and 18–30% malignant2,4,13,18,19,25. The most common PPS tumors originate from the salivary gland tissue of the deep parotid lobe or salivary tissue or ectodermic residua associated with the cranial nerves and the cervical
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Fig. 1. Tumor of the parapharyngeal space.
sympathetic chain or from the glomus body19. Tumors with a salivary gland etiology were the most frequent (30– 48%), followed by tumors of neurogenic origin (20–32%), which was comparable with other studies2,4,13,18,19,25. A smaller number of studies claim neurogenic tumors are the most frequent, accounting for 57%2,5. Paragangliomas were reported in studies by BATSAKIS and SNEIGE4 in 11%, by MALONE et al.18 in 12%, by CARRAU et al.5 in 40%; their incidence in this study was 5%. The most frequent malignant tumors in this study were adenocarcinoma, non-Hodgkin’s lymphoma, squamous cell carcinoma and metastatic lesions. Other studies described mucoepidermoid carcinoma and metastatic disease18, adenoid cystic carcinoma25 salivary malignancies and lymphoreticular lesions4, malignancy originating from neural tissue2,5 mucoepidermal carcinoma, adenoid cystic carcinoma13 and the rarely seen ganglioneuroblastoma7, and myofibroblastic sarcoma23. Most studies failed to analyze thoroughly the symptomatology and clinical signs of PPS tumors; instead they were mentioned as tumors of scarce symptomatology with an existing growth on the neck or lateral pharyngeal wall. In a large number of patients the tumors were detected on regular checkups or examinations due to suspicion of other diseases2,11,13,19,25. This is why the authors made a detailed analysis of symptoms and clinical signs based on evaluation of the medical records. The most frequent symptoms reported in literature are: growth on the neck
[(Fig._2)TD$IG]
(46%), pain (20%), dysphagia (13%), and pharyngeal growth (9%)5,19. SAN21 reported dysphagia as a TORO et al. leading symptom. In the present study, 14 (17%) patients had no symptoms while the most often symptom was dysphagia, in 35% of cases, followed by foreign body sensation in 21% and pain in 17%.
Fig. 2. Axial view showing tumor of the PPS.
Clinical signs reported in the literature are: neck mass (53%), followed by pharyngeal mass (51%), and parotid mass (9%)5,13. In this study, the predominant signs were pharyngeal mass (51%), neck mass (22%) and parotid mass (13%) (Fig. 1). Analysis of the imaging methods revealed that the most important parameters were: localization of tumor preor poststyloid, size and extension, relation to the parotid gland, relation to the blood vessels and tissue characteristics of the tumors and fat planes. Imaging methods contributed the most to diagnosis. MR and CT imaging provide excellent PPS images19. Contrast CT is an effective imaging method. Many authors have reported the superiority of MR over CT because it ensures better soft tissue differentiation and the possibility of MR angiography and better identification of the carotid artery2,22. CT imaging, although less precise in soft tissue evaluation, better depicts the styloid process and bony erosions. Anterior displacement of the carotid artery and the internal jugular vein is suggestive for poststyloid tumors, mostly neurinomas while salivary lesions displace vessels posteriorly22. In prestyloid tumors, a preserved fat plane between the deep lobe of the parotid gland and the tumor is indicative of a separate tumor originating from the extraparotid minor
[(Fig._3)TD$IG]
Parapharyngeal space tumors
Fig. 3. Multi-slice CT showing tumor of the PPS.
salivary glands13. Most often, poststyloid space tumors are of neurogenic etiology, schwannomas and paragangliomas19. CT with contrast and MR imaging with gadolinium are often used together to provide complementary information, which allows the surgeon to delineate the size, precise localization and probable cause of these tumors9,17. In this study, CT (70%) was the predominant diagnostic method used, because of the time period covered (the past 20 years). CT scanning is generally used for differentiating prestyloid and [(Fig._4)TD$IG]poststyloid space tumors, determining
the size and extension of benign and malignant neoplasm, parotid or non-parotid, and, to a lesser degree, vascularization2,5,19 (Fig. 2). Recently, MSCT has been applied in three cases, which resulted in accurate tumor diagnosis, localization, size and determination of tumor relation to adjacent structures (Figs 3 and 4). In all cases suspected of paraganglioma, arteriography was indicated5,8,13,19. The PPS is a relatively inaccessible space for a surgeon due to the localization of the superficial parotid lobe, facial nerve, mandible, carotid artery and jugular
Fig. 4. Multi-slice CT showing tumor of the PPS.
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vein. The origin of most PPS tumors is from the deep lobe or neurogenic, and they may be reached by a transcervical–transparotid or transcervical approach. Surgery is the method of choice for PPS tumor management5. The choice of approach should be dictated by tumor localization, size and its relation to the carotid artery and jugular vein as well as suspicion of malignancy and relation to the base of the skull. External transcervical approaches are preferred for better neurovascular control and surgical radicality13,16,25 A transcervical approach was used in 62% of the present cases; other authors have reported the use of this approach 60–87% of the time7,13. The transcervical approach is indicated for the removal of tumors originating from the minor salivary glands as well as for schwannommas and paragangliomas in the poststyloid space (40%13, 48%5 and 100%18) while in this study it was employed in 26%. The transcervical approach allows direct access to the PPS; removal of the tumor is often improved by excision of the submandibular gland, vessel ligation and dividing digastric, stylohyoid and styloglossal muscles and stylomandibular ligament and anterior dislocation of the mandible1,18,20,25 as used by the authors. The transcervical–transparotid approach is suitable for prestyloid tumors arising in the deep lobe of the parotid gland (46%3 and 11%5) presented in this study in 31% of patients. Parotidectomy incision is extended to the level of the greater cornu of the hyoid bone. This approach requires identification and preservation of the main trunk of the facial nerve. The transoral approach may be used in carefully selected cases2,9,11,16,19. According to the authors’ results, 13 (21%) patients operated on using this approach had their tumors removed completely and there was no recurrence. ALISON et al.2 applied this method in 13% of operated patients. Watertight closure provides uncomplicated healing. The postoperative nutrition of patients included a nasogastric tube (72 h). Many authors do not use this approach because of the risk of injuring the blood vessels and the possibility of total tumor extirpation5,13,25. The combined approach (transcervical and transoral) may be used for the removal of benign sizeable tumors without mandibular osteotomy, and it makes the stay shorter and reduces the possibility of sequelae in the authors’ experience in 17% and 4–39%, respectively2,16. Blood vessels were identified and secured with vascular loops in a non-constricting fash-
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ion. In these cases, a nasogastric tube was used for alimentation for 5 days. In all cases using the transmandibular approach, the airway should be secured with a tracheotomy5,19,25, which was carried out in three (5%) patients with the transcervical– transmandibular approach. This approach is used in rare cases (2–9% of the time2,13,19) and, according to the authors’ experience, it is indicated for malignant tumors5,19. Osteotomy was performed in the premolar region; the literature describes both single26 and double osteotomies3,13–15. In surgery of the PPS tumors, the surgeon must take care not to damage and rupture the capsule of the pleomorphic adenoma. In the authors’ experience, tracheotomy is not indicated often (in 7% of patients), and in 6–27% according to other authors5,18. In benign tumor accessibility, safety and completeness of resection direct the selection of approach. In malignant tumors, radicality of resection and options for reconstruction and rehabilitation and additional oncologic therapy are the factors defining the selection of the surgical approach. The authors consider that malignant tumors of this space always require additional therapy (radio and/or chemotherapy) in cases with high-degree malignant tumors, in indefinite or positive surgical margins5,13,16. In the literature, data on PPS tumor control are often incomplete, probably due to the small number of tumors and their variability. The frequency of benign tumor recurrence is low2,13,18,25, in this series only one recurrence was recorded. Many authors report that malignant PPS tumors have a poor prognosis2,13,16,18,25. Incision biopsy carries the risk of tumor dissemination, and is suggested in suspicion of malignant neoplasm5,25. Fine-needle aspiration biopsy (FNAB), guided or not, may contribute to the preoperative evaluation of PPS tumors, especially benign ones (90%)1,2,10,12,23,24. The role of FNAB in preoperative evaluation of patients with PPS tumors is unclear2,13. FNAB correlates with definite histopathological findings in 65%, and has as high as 87% sensitivity for detection of malignant diseases13. FNAB is helpful in evaluating these tumors, because tumor dissemination and injury of the major blood vessels can be avoided, when an open incision biopsy is contraindicated18. It is particularly recommended when lymphoma, metastatic lesions and other malignant neoplasms are suspected; it is not suggested in paragangliomas13,19. If imaging methods indicate a benign tumor, the authors’ opinion is that preoperative
biopsy is not necessary. The authors’ experience with FNAB and PPS tumors is very modest. In this study, ex tempore biopsy was performed in 12 patients suspected of malignancy, which was verified by FNAB in 8 patients. In this study, postoperative complications were reported in 25%, most commonly facial nerve lesions. Lesions of cranial nerves in patients with removed neurogenic tumors25 or malignant tumors and paragangliomas account for 30–48% of cases5,13,16,18. First bite syndrome is not a common complication6. Many sequelae of surgical treatment are transitory and a permanent deficit is present in 11%.5 In conclusion, it is most important to evaluate localization, diameter of PPS tumor and relation to neurovascular structures. The most frequent PPS tumors are salivary tumors (43%) and neurogenic tumors (29%). Malignant tumors were present 26% of the time. Imaging methods are essential for evaluating the PPS mass. CT and/or MR are necessary for deciding on the surgical approach. Complete surgical excision is considered the gold standard. External transcervical approaches are preferred. Preoperative biopsy is performed only if malignancy is suspected and non-surgical treatment or FNAB is given in all cases except suspected vascular tumors. Funding
None. Competing interests
None declared. Ethical approval
This study complies with the guidelines laid down in the Declaration of Helsinki; Recommendations guiding physicians in biomedical research involving human subjects (adopted by the 18th WMA, amended by the 29th WMA, the 35th WMA and the 41st WMA). This study has been approved by the ethical committee of the Clinical Centre of Serbia, and the subjects involved gave informed consent for their inclusion in the study. References 1. Abemayor E, Lufkin R. Enhancing access to the parapharyngeal space. Laryngoscope 2002: 112: 757–759. 2. Alison R, Waal IVD, Snow G. Parapharyngeal tumors—a review of 23 cases. Otolaryngology 1989: 199–203.
3. Attia El. Bentley KC, Head T, Mulder D. A new external approach of the pterygomaxillary fossa and parapharyngeal space. Head Neck Surg 1984: 6: 884–888. 4. Batsakis J, Sneige N. Parapharyngeal and retropharyngeal space diseases. Ann Otol Rhinol Laryngol 1989: 320– 321. 5. Carrau R, Myers E, Johnson J. Management of tumors arising in the parapharyngeal space. Laryngoscope 1990: 100: 583–589. 6. Chiu A, Cohen J, Burningham A, Andersen P, Davidson B. First bite syndrome: a complication of surgery involving the parapharyngeal space. Head Neck 2002: 10: 996–999. 7. Danosos D, Santos V, Ruffy M, Polisar I, Torno R. Ganglioneuroma of the parapharyngeal space. Bull NY Acad Med 1979: 56: 616–622. 8. Davidovic L, Ilic N, Dimitrijevic M, Ðukic V, Dzodic R. Surgical management of cervical paragangliomas. Am Surg 2008: 74: 1171–1176. 9. Ducic Y, Oxford L, Pontius AT. Transoral approach to the superomedial parapharyngeal space. Otolaryngol Head Neck Surg 2006: 134: 466–470. 10. Farag TY, Lin RF, Koch WM, Califano JA, Cummings CW, Farinola MA, Tufano RP. The role of preoperative CT-guided FNAB for parapharyngeal space tumors. Otolaryngol Head Neck Surg 2007: 136: 411–414. 11. Goodwin Jr W, Chandler J. Transoral excision of lateral parapharyngeal space tumors presenting intraorally. Laryngoscope 1988: 98: 266–270. 12. Handa U, Bal A, Mohan H, Dass A. Parapharyngeal paraganglioma: diagnosis on fine-needle aspiration. Am J Otolaryngol Head Neck Med Surg 2005: 26: 360–361. 13. Khafif A, Segev Y, Kaplan DM, Gil Y, Fliss DM. Surgical management of parapharyngeal space tumors—a 10 year review. Otolaryngol Head Neck Surg 2005: 132: 401–406. 14. Kolokythas A, Eisele D, El-Sayed I, Schmidt B. Mandibular osteotomies for access to select parapharyngeal space neoplasms. Head Neck 2009: 10: 102– 110. 15. Lazaridis N, Antoniades K. Double mandibular osteotomy with coronoidectomy for tumours in the parapharyngeal space. Br J Oral Maxillofac Surg 2003: 41: 142–146. 16. Luna-Ortiz K, Navarrete-Aleman EJ, Granados-Garcia M, HerreraGomez A. Primary parapharyngeal space tumors in a Mexican cancer center. Otolaryngol Head Neck Surg 2005: 132: 587–591. 17. Mafee MF, Venkatesan TK, Ameli N, Camras L, Friedman M. Tumors of parotid gland and parapharyngeal space-role of computed tomography and
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magnetic resonance imaging. Head Neck Surg 1996: 7: 348–357. Malone J, Agrawal A, Schuller D. Safety and efficacy of transcervical resection of parapharyngeal space neoplasms. Ann Otol Rhinol Laryngol 2001: 110: 1093–1098. Myers EN, Johnson JT, Curtin HG. Tumors of parapharyngeal space. 4th ed. In: Myers EN, Suen JY, Myers JN, Hanna EY, eds: Cancer of the Head and Neck, vol. 22. Philadelphia: WB Saunders 2003: 511–513. Orabi AA, Riad MA, O‘Regan MB. Stylomandibular tenotomy in the transcervical removal of large benign parapharyngeal tumours. Br J Oral Maxillofac Surg 2002: 40: 313–316. Santoro R, De Meester W, Coscarelli S, Polli G. Multiple neurinomas of
the parapharyngeal space. Eur Arch Otorhinolaryngol 1997: 254: 301–303. 22. Som PM, Sacher M, Stollman A, Biller H, Lawson W. Common tumors of the parapharyngeal space-imaging diagnosis. Head Neck Radiol 1988: 169: 81– 85. 23. Takahama A, Nascimento AG, Brum MC, Vargas PA, Lopes MA. Low-grade myofibroblastic sarcoma of the parapharyngeal space. Int J Oral Maxillofac Surg 2006: 35: 965–968. 24. Thomas G, Pandey M, Jayasree K, Pradeep V, Abraham EK, Iyoe EM, Krishnan Nair M. Parapharyngeal metastasis from papillary microcarcinoma of thyroid: report of a case diagnosed by peroral fine needle aspiration. Br J Oral Maxillofac Surg 2002: 40: 229– 231.
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25. Work PW, Hybels RL. A study of tumors of the parapharyngeal space. Laryngoscope 1974: 1748–1755. 26. Zitsch RP, Patenaude B, Tidmore T. An extraoral parapharyngeal space approach via vertical ramus osteotomy. Am J Otolaryngol Head Neck Surg 2007: 28: 330–333. Address: Milovan V. Dimitrijevic Clinic of Otorhinolaryngology and Maxillofacial Surgery Clinical Center of Serbia Pasterova 2 11000 Beograd Serbia Tel: +381 11 2643 694 Fax: +381 11 2643 694 E-mail: [email protected]