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Congenital cysts and fistulas of the neck
International Journal of Pediatric Otorhinolaryngology 55 (2000) 117 – 124 www.elsevier.com/locate/ijporl
Congenital cysts and fistulas of the neck R. Nicollas, B. Guelfucci, S. Roman, J.M. Triglia * Ser6ice d’ORL Pe´diatrique, Fe´de´ration ORL, Hoˆpital de la Timone, Bd Jean Moulin, 13385 Marseille Cedex 05, France Received 11 February 2000; received in revised form 28 June 2000; accepted 28 June 2000
Abstract This retrospective study describes a series of 191 children treated for congenital cysts and fistulas of the neck between 1984 and 1999 in the pediatric ORL Department of La Timone Children’s Hospital. Preauricular fistulas and cystic hygromas were not included. The anomalies in this series were classified as either malformations of the midline or malformations of laterocervical region. Malformations of the midline included the thyroglossal duct cysts (n= 102) and dermoid cysts (n=21). The most common malformations of the laterocervical region were cysts and fistulas of the second cleft (n =37) followed by those of the first cleft (n= 20),those of the fourth pouch (n= 7), and thymic cysts (n= 4). Diagnosis of malformations of the midline is usually straightforward. However, diagnosis of malformation of the laterocervical region can be problematic. Misdiagnosis often leads to inadequate treatment with recurrence and functional as well as cosmetic sequelae. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Branchial cleft; Branchial pouch; Congenital cysts; Cervical malformation; Thymic cysts; Thyroglossal cysts
1. Introduction Some congenital anomalies of the neck are commonplace in pediatric practice. This is the case for thyroglossal tract cysts, unilocular branchial cysts, and fistulas of the second cleft. However, less common lesions such as fistulas of the first cleft and cysts of the fourth pouch may pose problems of misdiagnosis and recurrence. Malformation of the midline such as thyroglossal duct cysts and dermoid cysts are embryologically different from malformation of the laterocervical region. Awareness of the characteristic anatomic and clinical features of each lesion is essential not * Corresponding author.
only to allow accurate diagnosis but also to achieve complete surgical excision for recurrencefree treatment. The purpose of this report is to present our 15-year experience in the management of congenital anomalies of the neck in children. Cystic hygromas and preauricular fistulas were not included in this study.
2. Embryological background Embryological development of the laterocervical region is closely linked with that of the branchial apparatus which forms within the first month of intrauterine life. In man, the branchial arches are arranged in pairs on either side of the
0165-5876/00/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 1 6 5 - 5 8 7 6 ( 0 0 ) 0 0 3 8 4 - 0
Entoblastes (pouches) Eustachian tube
Nerve: V2, V3 Middle ear
Muscles: mastication muscles
Ectoblast (clefts) External auditory canal Mesoblast (archs) Cartilage/bone: mandible, head and neck of malleus, incus body
First arch
Table 1 Development of first four arches
Nerve: VII Palatine tonsil
Platysma Cartilage/bone: malleus handle, incus long process, stapes superstructure, styloid, lesser cornus and upper part of body of hyoid bone Muscles: skin muscles of the face Artery: stapedial artery
Second arch
Nerve: IX Inferior parathyroid, thymus, upper part of piriform sinus
Muscles: stylopharyngeal muscle Artery: internal carotid artery
Cartilage/bone: greater cornus and lower part of body of the hyoid bone
Third arch
Muscles: crico-thyroı¨d muscle Artery: aortic arch (left); subclavian artery (right) Nerve: superior laryngeal nerve Superior parathyroid, C-cells of thyroid, lower part of piriform sinus
Cartilage/bone: thyroid, arytenoı¨ds
Fourth arch
118 R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124
midline. Morphologically, the apparatus can be described as a succession of folds and grooves corresponding to the branchial clefts and pouches. Four arches can be clearly identified on the embryo. A rudimentary fifth arch appears but quickly regresses [1]. Each arch coalesces with its contralateral counterpart ventrally on the midline. Each merged arch gives rise to a bone and cartilage derivate, one or more striated muscles, a mixed cranial nerve, and a vascular component (see Table 1). The second arch then expands downward to meet and merge with the fifth arch thus covering the second third and fourth arch and forming the cervical sinus. The definitions of several structures should be clarified. The term ‘cleft’ refers to the ectoblastic furrow in each arch. The term ‘pouch’ refers to the entoblastic depression that is found on each arch. The term ‘cyst’ refers to a component completely detached from the ectoblastic or entoblastic zones. Unlike malformations of the laterocervical region, malformations of the midline are unrelated to development of the branchial apparatus [1]. These anomalies result either from defective closure of the midline or persistence of remnants after thyroid migration. Dermoid cysts and mentosternal fistulas (none in this series) are examples of closure defects while thyroglossal tract cysts are examples of a migration remnant.
3. Patients and methods Between 1984 and 1999, 191 children underwent surgical treatment for congenital cysts or
119
fistulas of the neck in the pediatric department of Otolaryngology of La Timone Children’s Hospital in Marseille, France. Embryologically, the anomalies in this series were classified as either malformations of the midline or malformation of the laterocervical region (Table 2). Anatomically the lesions could be classified as incomplete fistulas presenting a dead-end fistulous tract, complete fistulas presenting with two open-ends, and isolated cysts. The records of these patients were examined to determine age, sex, age at discovery of the lesion, the type and side of the anomaly, age at the time of treatment, surgical history, and follow-up. Children with preauricular fistulas and cystic lymphangiomas were not included in this study.
3.1. Laterocer6ical malformations Malformations of the first arch were observed in 20 patients in this series (10%). Mean age at the time of the first procedure at our institution was 6.5 years (range, birth–17 years). Females outnumbered males 17 to three. Lesions occurred equally on the left and right. Clinical manifestations in these patients were classified as either cervical, parotid, and auricular. These manifestations could be isolated or associated in the same patient. Cervical symptoms (n= 13) develop in relation with discharge of clear fluid from a fistulous tract ending in the region near the mandibular angle. When infection occurs, this fluid may become purulent resulting in submandibular adenitis. Parotid symptoms (n= 8) involve the presence of an isolated cyst-like mass located at the lower end of the parotid or in the mastoid region. In these cases, the lesion is usually discov-
Table 2 Distribution of malformations in this series (n= 191) Cyst First cleft Second cleft Thymic cysts Fourth pouch Thyroglossal duct cysts Dermoid cysts
3 8 4 1 102 21
Complete fistula 5 – – – – –
Incomplete fistula 12 29 – 6 – –
Total 20 37 4 7 102 21
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ered after sudden enlargement related to inflammation. Auricular symptoms (n= 6 including one isolated case) consist of purulent or mucopurulent otorrhea. Anatomically, these lesions were classified as incomplete fistulas in 12 cases, complete fistulas in five, and cysts in three. Cervical fistulas were always located within a triangle formed by the symphysis menti, hyoid bone, and tragus. Otoscopy was performed in all cases. In two cases, otoscopic findings revealed the presence of a tympanic membrane attachment. This finding appeared as a right triangle with the upper tip extending to the handle of the malleus, the base resting on the external auditory canal, and the medial side pressing against the pars tensa. Thirteen of these patients had undergone one or more previous surgical treatments involving incision, drainage, or incomplete excisions. Treatment at our institution consisted of complete excision using the parotidectomy approach with control of the facial nerve in 19 of 20 cases. In the remaining case involving a duplication of the external auditory canal, treatment could be achieved by direct incision of the fistula without jeopardizing the facial nerve. Malformation of the second cleft was found in 37 patients (19%) including three with bilateral anomalies (40 lesions). The sex distribution was 24 males and 13 females. Unilateral lesions were located on the right side in 15 cases and left in 19. Anatomically, two distinct forms were observed, i.e. cutaneous fistulas (n =29) and cysts (n = 8). The location of the cyst was superficial in three cases, prevascular in two, and between the large vessels and pharyngeal wall in two. Mean age at the time of the first procedure at our institution was 3 years for patients with fistulas (range: 1 month–14 years) and 13 years for patients with cysts (range: 23 months – 17 years). Thymic cysts were found in four patients (2%). All these lesions occurred on the left. Mean age at the time of the first procedure at our institution was 13 years (extremes: 3 – 18 years). Sex distribution was two males and two females. Based on anatomical findings these lesions were classified as either cervicothoracic cysts (n =3) and cervical cysts (n= 1).
Fistula of the fourth pouch was observed in seven children (4%). Sex distribution was four females and three males. All these lesions occurred on the left. Mean age at the time of discovery was 39 months (range: birth–12 years). All patients presented a laterocervical mass in the thyroid region. Three of the seven had undergone two previous procedures prior to treatment at our institution. Hypopharyngeal endoscopy demonstrated a fistula at the bottom of the piriform sinus in five cases and in the middle of the anterior wall in one. In the remaining case, no fistula was observed. CT-scan showed a heterogeneous, contrast-enhanceable mass near the left side of the thyroid. In 50% of cases, thyroid parenchyma showed infection-related changes. Patients were treated using conventional techniques involving resection of the tumor with dissection and ligature of the fistulous tract flush with the piriform sinus. Thyroid lobectomy was necessary in 4 cases.
3.2. Malformations of the midline Thyroglossal cysts were identified and treated in 102 children in this series (53.4%). The sex distribution was 51 males and 51 females. Diagnostic work-up included ultrasonography of the neck to assess the condition of the thyroid gland and rule out thyroid ectopia (not observed in this series). Mean age at the time of the procedure was 5.6 years (range: 6 months–19 years). Fifteen patients had undergone previous surgical treatment, i.e. one procedure in nine cases, two procedures in five, and three procedures in one. Anatomical variations included lesions in the left paramedian region, lesions in the right submaxillary region, and a form with two distinct, histologically documented fistulous tracts passing in front and behind the hyoid bone. Associated lesions included a fistula on the nose in one patient, a cyst of the vallecula in one, and a preauricular fistula in two (one unilateral and one bilateral). Dermoid cyst was diagnosed in 21 patients (11%). Sex distribution was 14 females and four males. Mean age at the time of surgery at our institution was 16 months (range: 9–22 months). The cyst was located on the midline of the neck in 15 cases, above the sternum in five, at the level of
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124
the hyoid bone in four, in the middle of the neck in four, and under the chin in two. In the remaining three cases, the cyst was in the right paramedian region, right submaxillary region, and at the entrance of the external auditory canal. Initial presentation was an isolated mass in 16 of 18 cases. The presenting symptom in the other two cases was infection. In all cases, treatment consisted of complete surgical excision.
4. Results
4.1. Laterocer6ical malformations In patients involving malformations of the first arch, the course of the fistulous tract passed above the facial nerve in 12 patients, below the facial nerve in five, and between the branches of the facial nerve in two. Recurrence was observed during postoperative recovery in two children (10%) requiring re-operation within nine months. One newborn who demonstrated facial paralysis in relation with a suppurative infection of the lesion achieved complete recovery after surgery. With a mean follow-up of 4 years including the two recurrences (range: 20 months – 15 years) no patient has reported further anomaly-related symptoms. In any patient treated for malformations of the second cleft in this series, no complication or recurrence has been observed with a mean followup of 5.5 years (range: 5 months – 15 years). Mean follow-up in patients treated for thymic cyst is 11 years (range: 4 – 15 years). No complication or recurrence has been observed. The youngest patient in this group (4 months old at the time of the procedure) has not developed immunodeficiency. Histological examination revealed the presence of Hassall’s corpuscles in all surgical specimens. In any patient treated for fistula of the fourth pouch, no recurrence has been observed with a mean follow-up of 4 years (range, 9 months – 9 years). Vocal cord paralysis occurred in two patients. One of these patients recovered.
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4.2. Malformations of the midline No recurrence has been observed in 87 of the 96 children (90.6%) treated for thyroglossal duct cysts with a mean follow-up of 9.7 years (range: 2 months–15 years). Seven children have presented recurrences. In six cases (6.3%), a single reoperation was performed within 1–12 months after the initial procedure. In one case, a third procedure has been required. The remaining two children were lost to follow-up after the first postoperative examination. Of the seven children presenting recurrences, all but one, in whom the lesion had been misdiagnosed as a dermoid cyst, underwent resection of the hyoid bone. No recurrence has been noted in any patient treated for dermoid cyst with a mean follow-up of 6 years (range: 10 months–15 years).
5. Discussion Study of the cervical region has shown that the midline and laterocervical regions are embryologically distinct. Development of the laterocervical regions depends on the branchial arches while that of the midline depends on proper closure of the embryo. This difference explains the distinction that must be made between malformations of the laterocervical region and malformations of the midline. Most reports in the literature have used the system proposed by Work (in [3]) for classification of fistulas of the first cleft. This system defines two types of fistulas, i.e. type I characterized by duplication of the external auditory canal and type II characterized by a fistulous tract between the external auditory canal and the parotid region. However, the clinical utility of Work’s classification is limited as shown by the series of Aronsohn et al. [2] in which 36% of lesions could not be classified. The most relavant findings for proper diagnosis are the clinical manifestations (cervical, parotid, or auricular) and clinical examination especially of the external auditory canal [3]. Another common finding in the literature is the high incidence of recurrence after previous inappropriate treatment [2,4]. In contrast recur-
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rence is rare after proper treatment. The recurrence rate in the present series was 10% (n = 2) which is comparable to rates reported elsewhere [2 – 5]. Cysts and fistulas of the second cleft have been attributed to persistence of the cervical sinus [4]. This mechanism would explain the close relation between the fistulous tract and the large cervical vessels. Cysts may be present as a well-delineated lesion or include a tract-like extension on one side [6]. According to Bailey (in [6]), cysts and fistulas of the second cleft can be divided into four groups according to anatomical location, i.e. type I occurring under the superficial aponeurosis of the neck, type II located in front of and externally to the large vessels, type III occurring between the branches of the carotid bifurcation, and type IV located between the large vessels and pharyngeal wall. Recurrence after surgical resection is uncommon. Several hypotheses have been proposed to explain the occurrence of thymic cysts. However, as stated by Millmann [7], based on extensive review of the literature on embryopathogenesis, none of these hypotheses has been clearly demonstrated. Zarbo [8] implicated either deterioration of the Hassall’s corpuscles or persistence of the pharyngothymic duct. Several classifications have been proposed for thymic cysts. Mikal (in [7]) distinguished three groups, i.e. ‘genuine’ thymic cysts (type I) due to persistence of the pharyngothymic duct, mixed thymic cysts (type II) developing in connection with fistulas between the skin and pharynx, and ‘false’ thymic cysts (type III) involving cysts originating from the branchial clefts but containing ectopic thymic tissue. Two commonly reported findings concerning thymic cysts are low incidence and frequent incidental discovery [4,6 – 13]. Most reported thymic cysts have been observed on the left laterocervical region [4,6,12] but lesions have also been reported on the right side as well as in other rare locations such as the midline and the submandibular region [10,13]. Malformations of the fourth pouch account for 1% of congenital malformations of the laterocervical regions described in various reports from the literature [4,14,15]. These anomalies have been attributed to persistence of the fourth pharyngob-
ranchialis duct which connects the pharynx to the ultimobranchial bodies. These lesions are located almost exclusively on the left [4,14–17]. The reason for this exclusive location has not been conclusively established. However it has been suggested that this finding may be related to the asymmetry observed in vascular development between the left and right fourth arches as well as the preferential left-sided development of the ultimobranchial bodies in most mammal species [18]. In fact, we believe that it would be more correct to refer to these lesions as malformations of the piriform sinus rather than of the third or fourth pouch. One of the patients treated for a fistula of the fourth pouch presented a fistulous tract emptying into the piriform sinus at a point located higher and more anteriorly than the others even though the fistulous tract and cysts were the same. Differential diagnosis of malformations of the fourth pouch can be difficult. In many series, misdiagnosis as localized thyroiditis was reported [16,19,20]. Laterocervical masses can also be associated with esophageal redundancy, suppurative thyroiditis, and adenitis. It should be noted that the diagnosis of digestive tract redundancy is more likely from a pediatric surgeon than a ORL surgeon. Pharyngo-laryngoscopy is the key to definitive diagnosis. All authors agree that curative treatment requires complete excision of the cyst and fistulous tract which must be ligated flush with the mucosa of the piriform sinus. However, the need for thyroidectomy is controversial. Most authors [16,20] recommend lobectomy solely to allow identification of the recurrent laryngeal nerve. Thyroglossal duct cysts account for around 40% of cervical malformations in children. According to Allard [21], peak incidence occurs during the first three decades of life. In this series, thyroglossal duct cysts accounted for 53% of lesions. This anomaly has been attributed to persistence of the tract formed during migration of the rudimentary thyroid gland between the base of the tongue and the anterior cervical region. To achieve curative treatment, the body of the hyoid bone must be resected with a margin of at least 5 mm on either side of the point of entry of the fistulous tract. Branches of the tract are possible
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124 Table 3 Key symptoms Symptom
Suggested Anomaly
Otorrhea with tympanic membrane adherence Mass or fistula in parotid region Fistula on anterior border of the sternocleidomastoid muscle Non infected latero-cervical ovoid mass Recurrent laterocervical abscess (especially on left), thyroiditis Mass in the anterior, median region that varies in size during rhinopharyngeal infection
Malformation of first cleft Malformation of second cleft Thymic cyst Malformation of fourth pouch Thyroglossal duct cyst
and must be treated. Unresected branches could account for cases of recurrence despite removal of the hyoid bone. Torsiglieri [22] estimated that dermoid cysts account for 10% of cervical tumors in children. This anomaly results from the inclusion of epidermoid tissue during fusion of the branchial arches. Palpation demonstrates an incompressible mass usually located outside the muscle layers. Variations in size during episodes of rhinopharyngeal infection are less pronounced in dermoid cysts than in thyroglossal duct cysts. However differential diagnosis between dermoid cysts and thyroglossal ducts cysts can be difficult when these lesion occur close to the hyoid bone. In conclusion, a shared prerequisite for successful management of all congenital malformation of the neck is the need for accurate diagnosis and full assessment before treatment. This implies a good knowledge of the embryology of the cervical region and of possible associated lesions. Practitioners should be aware of the ‘key’ symptoms suggesting diagnosis (Table 3). Curative treatment depends a skillful atraumatic dissection based on knowledge of the anatomical region and complete resection to prevent recurrence. References [1] S.W. Gray, J.E. Skandalakis, The pharynx and its derivates, in: Embryology for Surgeons, Saunders Company, Philadelphia, PA, 1972, pp. 15–33.
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[2] R.S. Aronsohn, J.G. Batsakis, D.H. Rice, W.P. Work, Anomalies of the first branchial cleft, Arch. Otolaryngol. Head Neck Surg. 102 (1976) 737 – 740. [3] J.M. Triglia, R. Nicollas, V. Ducroz, P.J. Koltai, E.N. Garabe´dian, First branchial cleft anomalies, Arch. Otolaryngol. Head Neck Surg. 124 (1998) 291 – 295. [4] J.R. Ford, A. Balakrishnan, J.N.G. Evans, C.M. Bailey, Branchial cleft and pouch anomalies, J. Laryngol. Otol. 106 (1992) 137 – 143. [5] K.D. Olsen, N.E. Maragos, L.H. Weiland, First branchial cleft anomalies, Laryngoscope 90 (1980) 423 – 435. [6] A. Pech, M. Cannoni, P. Gitenet, J.C. Palleri, Kystes et fistules du cou, Cahiers d’ORL 11 (8) (1976) 663 – 693. [7] B. Millman, S. Pransky, J.I.I.I. Castillo, T. Zipfel, W.E. Wood, Cervical thymic cyst anomalies, Int. J. Pediatr. Otorhinolaryngol. 47 (1999) 29 – 39. [8] R.J. Zarbo, K.D. McClatchey, R.G. Areen, S.B. Baker, Thymopharyngeal duct cyst: a form of cervical thymus, Ann. Otol. Rhinol. Laryngol. 92 (1983) 284 – 289. [9] J. Boyd, J. Templer, A. Havey, J. Walls, J. Decker, Persistent thymopharyngeal duct cyst, Otolaryngol. Head Neck Surg. 109 (1993) 135 – 139. [10] D. Kelley, M.E. Gerber, J.P. Willging, Cervicomediastinal thymic cysts, Int. J. Pediatr. Otorhinolaryngol. 39 (1997) 139 – 146. [11] S. Marra, A.J. Hotaling, W. Raslan, Cervical thymic cyst, Otolaryngol. Head Neck Surg. 112 (1995) 338 – 340. [12] M.B. Miller, M.A. De Vito, Cervical thymic cyst, Otolaryngol. Head Neck Surg. 112 (1995) 586 – 588. [13] A. Kacker, M. April, C.B. Markentel, F. Breuer, Ectopic thymus presenting as a solid submandibular neck mass in an infant: case report and review of the literature, Int. J. Pediatr. Otorhinolaryngol. 49 (1999) 241 – 245. [14] J.P. Inigues, A. Rivron, J.P. Priou, L. Beust, G. Le Clec’h, J. Bourdinie`re, Fistules de la 4e poche endobranchiale, a` propos de 4 cas, Ann. Otolaryngol. 110 (1993) 450 – 453. [15] Ph. Narcy, C. Aumont-Grosskopf, S. Bobin, Y. Manac’h, Fistulae of the fourth endobranchial pouch, Int. J. Pediatr. Otorhinolaryngol. 16 (1988) 157 – 165. [16] R. Nicollas, V. Ducroz, E.N. Garabe´dian, J.M. Triglia, Fourth branchial pouch anomalies, Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5 – 10. [17] R.M. Rosenfeld, H.F. Biller, Fourth branchial pouch sinus: diagnosis and treatment, Otolaryngol. Head Neck Surg. 105 (1991) 44 – 50. [18] Y. Manac’h, M.P. Morisseau, A. Perrin, J.P. Aboucaya, P. Roulleau, Le fond du sinus piriforme dans le traitement chirurgical des fistules de la quatrie`me poche endobranchiale, Ann. Otolaryngol. (Paris) 105 (1988) 391 – 396. [19] M. Dellandrea, B. Montinet, R. Stringini, P. Claude, Pseudo-thyroı¨dites suppure´es et fistules de la quatrie`me poche branchiale, J F ORL 40 (1991) 56 – 58.
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[20] F. Tovi, A. Gatot, J. Bar-Ziv, I. Yanay, Recurrent suppurative thyroiditis due to fourth branchial pouch sinus, Int. J. Pediatr. Otorhinolaryngol. 9 (1985) 89–96. [21] R.H. Allard, The thyroglossal cyst, Head Neck 5 (1982)
135 – 146. [22] A. Torsiglieri, L. Tom, A. Ross, R. Wetmore, S. Handler, W. Potsic, Pediatric neck masses: guidelines for evaluation, Int. J. Pediatr. Otorhinolaryngol 16 (1998) 199 – 210.
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Congenital cysts and fistulas of the neck R. Nicollas, B. Guelfucci, S. Roman, J.M. Triglia * Ser6ice d’ORL Pe´diatrique, Fe´de´ration ORL, Hoˆpital de la Timone, Bd Jean Moulin, 13385 Marseille Cedex 05, France Received 11 February 2000; received in revised form 28 June 2000; accepted 28 June 2000
Abstract This retrospective study describes a series of 191 children treated for congenital cysts and fistulas of the neck between 1984 and 1999 in the pediatric ORL Department of La Timone Children’s Hospital. Preauricular fistulas and cystic hygromas were not included. The anomalies in this series were classified as either malformations of the midline or malformations of laterocervical region. Malformations of the midline included the thyroglossal duct cysts (n= 102) and dermoid cysts (n=21). The most common malformations of the laterocervical region were cysts and fistulas of the second cleft (n =37) followed by those of the first cleft (n= 20),those of the fourth pouch (n= 7), and thymic cysts (n= 4). Diagnosis of malformations of the midline is usually straightforward. However, diagnosis of malformation of the laterocervical region can be problematic. Misdiagnosis often leads to inadequate treatment with recurrence and functional as well as cosmetic sequelae. © 2000 Elsevier Science Ireland Ltd. All rights reserved. Keywords: Branchial cleft; Branchial pouch; Congenital cysts; Cervical malformation; Thymic cysts; Thyroglossal cysts
1. Introduction Some congenital anomalies of the neck are commonplace in pediatric practice. This is the case for thyroglossal tract cysts, unilocular branchial cysts, and fistulas of the second cleft. However, less common lesions such as fistulas of the first cleft and cysts of the fourth pouch may pose problems of misdiagnosis and recurrence. Malformation of the midline such as thyroglossal duct cysts and dermoid cysts are embryologically different from malformation of the laterocervical region. Awareness of the characteristic anatomic and clinical features of each lesion is essential not * Corresponding author.
only to allow accurate diagnosis but also to achieve complete surgical excision for recurrencefree treatment. The purpose of this report is to present our 15-year experience in the management of congenital anomalies of the neck in children. Cystic hygromas and preauricular fistulas were not included in this study.
2. Embryological background Embryological development of the laterocervical region is closely linked with that of the branchial apparatus which forms within the first month of intrauterine life. In man, the branchial arches are arranged in pairs on either side of the
0165-5876/00/$ - see front matter © 2000 Elsevier Science Ireland Ltd. All rights reserved. PII: S 0 1 6 5 - 5 8 7 6 ( 0 0 ) 0 0 3 8 4 - 0
Entoblastes (pouches) Eustachian tube
Nerve: V2, V3 Middle ear
Muscles: mastication muscles
Ectoblast (clefts) External auditory canal Mesoblast (archs) Cartilage/bone: mandible, head and neck of malleus, incus body
First arch
Table 1 Development of first four arches
Nerve: VII Palatine tonsil
Platysma Cartilage/bone: malleus handle, incus long process, stapes superstructure, styloid, lesser cornus and upper part of body of hyoid bone Muscles: skin muscles of the face Artery: stapedial artery
Second arch
Nerve: IX Inferior parathyroid, thymus, upper part of piriform sinus
Muscles: stylopharyngeal muscle Artery: internal carotid artery
Cartilage/bone: greater cornus and lower part of body of the hyoid bone
Third arch
Muscles: crico-thyroı¨d muscle Artery: aortic arch (left); subclavian artery (right) Nerve: superior laryngeal nerve Superior parathyroid, C-cells of thyroid, lower part of piriform sinus
Cartilage/bone: thyroid, arytenoı¨ds
Fourth arch
118 R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124
midline. Morphologically, the apparatus can be described as a succession of folds and grooves corresponding to the branchial clefts and pouches. Four arches can be clearly identified on the embryo. A rudimentary fifth arch appears but quickly regresses [1]. Each arch coalesces with its contralateral counterpart ventrally on the midline. Each merged arch gives rise to a bone and cartilage derivate, one or more striated muscles, a mixed cranial nerve, and a vascular component (see Table 1). The second arch then expands downward to meet and merge with the fifth arch thus covering the second third and fourth arch and forming the cervical sinus. The definitions of several structures should be clarified. The term ‘cleft’ refers to the ectoblastic furrow in each arch. The term ‘pouch’ refers to the entoblastic depression that is found on each arch. The term ‘cyst’ refers to a component completely detached from the ectoblastic or entoblastic zones. Unlike malformations of the laterocervical region, malformations of the midline are unrelated to development of the branchial apparatus [1]. These anomalies result either from defective closure of the midline or persistence of remnants after thyroid migration. Dermoid cysts and mentosternal fistulas (none in this series) are examples of closure defects while thyroglossal tract cysts are examples of a migration remnant.
3. Patients and methods Between 1984 and 1999, 191 children underwent surgical treatment for congenital cysts or
119
fistulas of the neck in the pediatric department of Otolaryngology of La Timone Children’s Hospital in Marseille, France. Embryologically, the anomalies in this series were classified as either malformations of the midline or malformation of the laterocervical region (Table 2). Anatomically the lesions could be classified as incomplete fistulas presenting a dead-end fistulous tract, complete fistulas presenting with two open-ends, and isolated cysts. The records of these patients were examined to determine age, sex, age at discovery of the lesion, the type and side of the anomaly, age at the time of treatment, surgical history, and follow-up. Children with preauricular fistulas and cystic lymphangiomas were not included in this study.
3.1. Laterocer6ical malformations Malformations of the first arch were observed in 20 patients in this series (10%). Mean age at the time of the first procedure at our institution was 6.5 years (range, birth–17 years). Females outnumbered males 17 to three. Lesions occurred equally on the left and right. Clinical manifestations in these patients were classified as either cervical, parotid, and auricular. These manifestations could be isolated or associated in the same patient. Cervical symptoms (n= 13) develop in relation with discharge of clear fluid from a fistulous tract ending in the region near the mandibular angle. When infection occurs, this fluid may become purulent resulting in submandibular adenitis. Parotid symptoms (n= 8) involve the presence of an isolated cyst-like mass located at the lower end of the parotid or in the mastoid region. In these cases, the lesion is usually discov-
Table 2 Distribution of malformations in this series (n= 191) Cyst First cleft Second cleft Thymic cysts Fourth pouch Thyroglossal duct cysts Dermoid cysts
3 8 4 1 102 21
Complete fistula 5 – – – – –
Incomplete fistula 12 29 – 6 – –
Total 20 37 4 7 102 21
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ered after sudden enlargement related to inflammation. Auricular symptoms (n= 6 including one isolated case) consist of purulent or mucopurulent otorrhea. Anatomically, these lesions were classified as incomplete fistulas in 12 cases, complete fistulas in five, and cysts in three. Cervical fistulas were always located within a triangle formed by the symphysis menti, hyoid bone, and tragus. Otoscopy was performed in all cases. In two cases, otoscopic findings revealed the presence of a tympanic membrane attachment. This finding appeared as a right triangle with the upper tip extending to the handle of the malleus, the base resting on the external auditory canal, and the medial side pressing against the pars tensa. Thirteen of these patients had undergone one or more previous surgical treatments involving incision, drainage, or incomplete excisions. Treatment at our institution consisted of complete excision using the parotidectomy approach with control of the facial nerve in 19 of 20 cases. In the remaining case involving a duplication of the external auditory canal, treatment could be achieved by direct incision of the fistula without jeopardizing the facial nerve. Malformation of the second cleft was found in 37 patients (19%) including three with bilateral anomalies (40 lesions). The sex distribution was 24 males and 13 females. Unilateral lesions were located on the right side in 15 cases and left in 19. Anatomically, two distinct forms were observed, i.e. cutaneous fistulas (n =29) and cysts (n = 8). The location of the cyst was superficial in three cases, prevascular in two, and between the large vessels and pharyngeal wall in two. Mean age at the time of the first procedure at our institution was 3 years for patients with fistulas (range: 1 month–14 years) and 13 years for patients with cysts (range: 23 months – 17 years). Thymic cysts were found in four patients (2%). All these lesions occurred on the left. Mean age at the time of the first procedure at our institution was 13 years (extremes: 3 – 18 years). Sex distribution was two males and two females. Based on anatomical findings these lesions were classified as either cervicothoracic cysts (n =3) and cervical cysts (n= 1).
Fistula of the fourth pouch was observed in seven children (4%). Sex distribution was four females and three males. All these lesions occurred on the left. Mean age at the time of discovery was 39 months (range: birth–12 years). All patients presented a laterocervical mass in the thyroid region. Three of the seven had undergone two previous procedures prior to treatment at our institution. Hypopharyngeal endoscopy demonstrated a fistula at the bottom of the piriform sinus in five cases and in the middle of the anterior wall in one. In the remaining case, no fistula was observed. CT-scan showed a heterogeneous, contrast-enhanceable mass near the left side of the thyroid. In 50% of cases, thyroid parenchyma showed infection-related changes. Patients were treated using conventional techniques involving resection of the tumor with dissection and ligature of the fistulous tract flush with the piriform sinus. Thyroid lobectomy was necessary in 4 cases.
3.2. Malformations of the midline Thyroglossal cysts were identified and treated in 102 children in this series (53.4%). The sex distribution was 51 males and 51 females. Diagnostic work-up included ultrasonography of the neck to assess the condition of the thyroid gland and rule out thyroid ectopia (not observed in this series). Mean age at the time of the procedure was 5.6 years (range: 6 months–19 years). Fifteen patients had undergone previous surgical treatment, i.e. one procedure in nine cases, two procedures in five, and three procedures in one. Anatomical variations included lesions in the left paramedian region, lesions in the right submaxillary region, and a form with two distinct, histologically documented fistulous tracts passing in front and behind the hyoid bone. Associated lesions included a fistula on the nose in one patient, a cyst of the vallecula in one, and a preauricular fistula in two (one unilateral and one bilateral). Dermoid cyst was diagnosed in 21 patients (11%). Sex distribution was 14 females and four males. Mean age at the time of surgery at our institution was 16 months (range: 9–22 months). The cyst was located on the midline of the neck in 15 cases, above the sternum in five, at the level of
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the hyoid bone in four, in the middle of the neck in four, and under the chin in two. In the remaining three cases, the cyst was in the right paramedian region, right submaxillary region, and at the entrance of the external auditory canal. Initial presentation was an isolated mass in 16 of 18 cases. The presenting symptom in the other two cases was infection. In all cases, treatment consisted of complete surgical excision.
4. Results
4.1. Laterocer6ical malformations In patients involving malformations of the first arch, the course of the fistulous tract passed above the facial nerve in 12 patients, below the facial nerve in five, and between the branches of the facial nerve in two. Recurrence was observed during postoperative recovery in two children (10%) requiring re-operation within nine months. One newborn who demonstrated facial paralysis in relation with a suppurative infection of the lesion achieved complete recovery after surgery. With a mean follow-up of 4 years including the two recurrences (range: 20 months – 15 years) no patient has reported further anomaly-related symptoms. In any patient treated for malformations of the second cleft in this series, no complication or recurrence has been observed with a mean followup of 5.5 years (range: 5 months – 15 years). Mean follow-up in patients treated for thymic cyst is 11 years (range: 4 – 15 years). No complication or recurrence has been observed. The youngest patient in this group (4 months old at the time of the procedure) has not developed immunodeficiency. Histological examination revealed the presence of Hassall’s corpuscles in all surgical specimens. In any patient treated for fistula of the fourth pouch, no recurrence has been observed with a mean follow-up of 4 years (range, 9 months – 9 years). Vocal cord paralysis occurred in two patients. One of these patients recovered.
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4.2. Malformations of the midline No recurrence has been observed in 87 of the 96 children (90.6%) treated for thyroglossal duct cysts with a mean follow-up of 9.7 years (range: 2 months–15 years). Seven children have presented recurrences. In six cases (6.3%), a single reoperation was performed within 1–12 months after the initial procedure. In one case, a third procedure has been required. The remaining two children were lost to follow-up after the first postoperative examination. Of the seven children presenting recurrences, all but one, in whom the lesion had been misdiagnosed as a dermoid cyst, underwent resection of the hyoid bone. No recurrence has been noted in any patient treated for dermoid cyst with a mean follow-up of 6 years (range: 10 months–15 years).
5. Discussion Study of the cervical region has shown that the midline and laterocervical regions are embryologically distinct. Development of the laterocervical regions depends on the branchial arches while that of the midline depends on proper closure of the embryo. This difference explains the distinction that must be made between malformations of the laterocervical region and malformations of the midline. Most reports in the literature have used the system proposed by Work (in [3]) for classification of fistulas of the first cleft. This system defines two types of fistulas, i.e. type I characterized by duplication of the external auditory canal and type II characterized by a fistulous tract between the external auditory canal and the parotid region. However, the clinical utility of Work’s classification is limited as shown by the series of Aronsohn et al. [2] in which 36% of lesions could not be classified. The most relavant findings for proper diagnosis are the clinical manifestations (cervical, parotid, or auricular) and clinical examination especially of the external auditory canal [3]. Another common finding in the literature is the high incidence of recurrence after previous inappropriate treatment [2,4]. In contrast recur-
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rence is rare after proper treatment. The recurrence rate in the present series was 10% (n = 2) which is comparable to rates reported elsewhere [2 – 5]. Cysts and fistulas of the second cleft have been attributed to persistence of the cervical sinus [4]. This mechanism would explain the close relation between the fistulous tract and the large cervical vessels. Cysts may be present as a well-delineated lesion or include a tract-like extension on one side [6]. According to Bailey (in [6]), cysts and fistulas of the second cleft can be divided into four groups according to anatomical location, i.e. type I occurring under the superficial aponeurosis of the neck, type II located in front of and externally to the large vessels, type III occurring between the branches of the carotid bifurcation, and type IV located between the large vessels and pharyngeal wall. Recurrence after surgical resection is uncommon. Several hypotheses have been proposed to explain the occurrence of thymic cysts. However, as stated by Millmann [7], based on extensive review of the literature on embryopathogenesis, none of these hypotheses has been clearly demonstrated. Zarbo [8] implicated either deterioration of the Hassall’s corpuscles or persistence of the pharyngothymic duct. Several classifications have been proposed for thymic cysts. Mikal (in [7]) distinguished three groups, i.e. ‘genuine’ thymic cysts (type I) due to persistence of the pharyngothymic duct, mixed thymic cysts (type II) developing in connection with fistulas between the skin and pharynx, and ‘false’ thymic cysts (type III) involving cysts originating from the branchial clefts but containing ectopic thymic tissue. Two commonly reported findings concerning thymic cysts are low incidence and frequent incidental discovery [4,6 – 13]. Most reported thymic cysts have been observed on the left laterocervical region [4,6,12] but lesions have also been reported on the right side as well as in other rare locations such as the midline and the submandibular region [10,13]. Malformations of the fourth pouch account for 1% of congenital malformations of the laterocervical regions described in various reports from the literature [4,14,15]. These anomalies have been attributed to persistence of the fourth pharyngob-
ranchialis duct which connects the pharynx to the ultimobranchial bodies. These lesions are located almost exclusively on the left [4,14–17]. The reason for this exclusive location has not been conclusively established. However it has been suggested that this finding may be related to the asymmetry observed in vascular development between the left and right fourth arches as well as the preferential left-sided development of the ultimobranchial bodies in most mammal species [18]. In fact, we believe that it would be more correct to refer to these lesions as malformations of the piriform sinus rather than of the third or fourth pouch. One of the patients treated for a fistula of the fourth pouch presented a fistulous tract emptying into the piriform sinus at a point located higher and more anteriorly than the others even though the fistulous tract and cysts were the same. Differential diagnosis of malformations of the fourth pouch can be difficult. In many series, misdiagnosis as localized thyroiditis was reported [16,19,20]. Laterocervical masses can also be associated with esophageal redundancy, suppurative thyroiditis, and adenitis. It should be noted that the diagnosis of digestive tract redundancy is more likely from a pediatric surgeon than a ORL surgeon. Pharyngo-laryngoscopy is the key to definitive diagnosis. All authors agree that curative treatment requires complete excision of the cyst and fistulous tract which must be ligated flush with the mucosa of the piriform sinus. However, the need for thyroidectomy is controversial. Most authors [16,20] recommend lobectomy solely to allow identification of the recurrent laryngeal nerve. Thyroglossal duct cysts account for around 40% of cervical malformations in children. According to Allard [21], peak incidence occurs during the first three decades of life. In this series, thyroglossal duct cysts accounted for 53% of lesions. This anomaly has been attributed to persistence of the tract formed during migration of the rudimentary thyroid gland between the base of the tongue and the anterior cervical region. To achieve curative treatment, the body of the hyoid bone must be resected with a margin of at least 5 mm on either side of the point of entry of the fistulous tract. Branches of the tract are possible
R. Nicollas et al. / Int. J. Pediatr. Otorhinolaryngol. 55 (2000) 117–124 Table 3 Key symptoms Symptom
Suggested Anomaly
Otorrhea with tympanic membrane adherence Mass or fistula in parotid region Fistula on anterior border of the sternocleidomastoid muscle Non infected latero-cervical ovoid mass Recurrent laterocervical abscess (especially on left), thyroiditis Mass in the anterior, median region that varies in size during rhinopharyngeal infection
Malformation of first cleft Malformation of second cleft Thymic cyst Malformation of fourth pouch Thyroglossal duct cyst
and must be treated. Unresected branches could account for cases of recurrence despite removal of the hyoid bone. Torsiglieri [22] estimated that dermoid cysts account for 10% of cervical tumors in children. This anomaly results from the inclusion of epidermoid tissue during fusion of the branchial arches. Palpation demonstrates an incompressible mass usually located outside the muscle layers. Variations in size during episodes of rhinopharyngeal infection are less pronounced in dermoid cysts than in thyroglossal duct cysts. However differential diagnosis between dermoid cysts and thyroglossal ducts cysts can be difficult when these lesion occur close to the hyoid bone. In conclusion, a shared prerequisite for successful management of all congenital malformation of the neck is the need for accurate diagnosis and full assessment before treatment. This implies a good knowledge of the embryology of the cervical region and of possible associated lesions. Practitioners should be aware of the ‘key’ symptoms suggesting diagnosis (Table 3). Curative treatment depends a skillful atraumatic dissection based on knowledge of the anatomical region and complete resection to prevent recurrence. References [1] S.W. Gray, J.E. Skandalakis, The pharynx and its derivates, in: Embryology for Surgeons, Saunders Company, Philadelphia, PA, 1972, pp. 15–33.
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[2] R.S. Aronsohn, J.G. Batsakis, D.H. Rice, W.P. Work, Anomalies of the first branchial cleft, Arch. Otolaryngol. Head Neck Surg. 102 (1976) 737 – 740. [3] J.M. Triglia, R. Nicollas, V. Ducroz, P.J. Koltai, E.N. Garabe´dian, First branchial cleft anomalies, Arch. Otolaryngol. Head Neck Surg. 124 (1998) 291 – 295. [4] J.R. Ford, A. Balakrishnan, J.N.G. Evans, C.M. Bailey, Branchial cleft and pouch anomalies, J. Laryngol. Otol. 106 (1992) 137 – 143. [5] K.D. Olsen, N.E. Maragos, L.H. Weiland, First branchial cleft anomalies, Laryngoscope 90 (1980) 423 – 435. [6] A. Pech, M. Cannoni, P. Gitenet, J.C. Palleri, Kystes et fistules du cou, Cahiers d’ORL 11 (8) (1976) 663 – 693. [7] B. Millman, S. Pransky, J.I.I.I. Castillo, T. Zipfel, W.E. Wood, Cervical thymic cyst anomalies, Int. J. Pediatr. Otorhinolaryngol. 47 (1999) 29 – 39. [8] R.J. Zarbo, K.D. McClatchey, R.G. Areen, S.B. Baker, Thymopharyngeal duct cyst: a form of cervical thymus, Ann. Otol. Rhinol. Laryngol. 92 (1983) 284 – 289. [9] J. Boyd, J. Templer, A. Havey, J. Walls, J. Decker, Persistent thymopharyngeal duct cyst, Otolaryngol. Head Neck Surg. 109 (1993) 135 – 139. [10] D. Kelley, M.E. Gerber, J.P. Willging, Cervicomediastinal thymic cysts, Int. J. Pediatr. Otorhinolaryngol. 39 (1997) 139 – 146. [11] S. Marra, A.J. Hotaling, W. Raslan, Cervical thymic cyst, Otolaryngol. Head Neck Surg. 112 (1995) 338 – 340. [12] M.B. Miller, M.A. De Vito, Cervical thymic cyst, Otolaryngol. Head Neck Surg. 112 (1995) 586 – 588. [13] A. Kacker, M. April, C.B. Markentel, F. Breuer, Ectopic thymus presenting as a solid submandibular neck mass in an infant: case report and review of the literature, Int. J. Pediatr. Otorhinolaryngol. 49 (1999) 241 – 245. [14] J.P. Inigues, A. Rivron, J.P. Priou, L. Beust, G. Le Clec’h, J. Bourdinie`re, Fistules de la 4e poche endobranchiale, a` propos de 4 cas, Ann. Otolaryngol. 110 (1993) 450 – 453. [15] Ph. Narcy, C. Aumont-Grosskopf, S. Bobin, Y. Manac’h, Fistulae of the fourth endobranchial pouch, Int. J. Pediatr. Otorhinolaryngol. 16 (1988) 157 – 165. [16] R. Nicollas, V. Ducroz, E.N. Garabe´dian, J.M. Triglia, Fourth branchial pouch anomalies, Int. J. Pediatr. Otorhinolaryngol. 44 (1998) 5 – 10. [17] R.M. Rosenfeld, H.F. Biller, Fourth branchial pouch sinus: diagnosis and treatment, Otolaryngol. Head Neck Surg. 105 (1991) 44 – 50. [18] Y. Manac’h, M.P. Morisseau, A. Perrin, J.P. Aboucaya, P. Roulleau, Le fond du sinus piriforme dans le traitement chirurgical des fistules de la quatrie`me poche endobranchiale, Ann. Otolaryngol. (Paris) 105 (1988) 391 – 396. [19] M. Dellandrea, B. Montinet, R. Stringini, P. Claude, Pseudo-thyroı¨dites suppure´es et fistules de la quatrie`me poche branchiale, J F ORL 40 (1991) 56 – 58.
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