Persistent thymopharyngeal duct cyst

Rare thymopharyngeal duct cyst presentation in an adult patient

Retained thymic tissue may occur anywhere along the path of descent of the thymus. Cervical thymic cysts are a rare cause of benign neck masses. Thymopharyngeal duct cysts are thymic cysts that span the length of the neck and extend towards the mediastinum. These lesions are rare and classically have been described in paediatric patients. Here, we present the case of a 23-year-old woman with a left-sided neck mass, which was found to be a thymopharyngeal duct cyst. Multiple analytic modalities including the clinical presentation, imaging, operative findings and histology were required to confirm the diagnosis and are discussed below.

Ectopic cervical thymus in children: Clinical and radiographic features

OBJECTIVES

Ectopic thymus is rare and can be a diagnostic challenge. This study evaluated the management of children radiographically diagnosed with ectopic cervical thymus.

METHODS

A retrospective review of 100 patients was performed. Data related to clinical presentation, radiological imaging, pathology, and management were collected. Changes in lesion volume were tracked over time. Clinical characteristics were compared based on lesion location in the neck using analysis of variance modelling.

RESULTS

There were 115 lesions with radiographic features of ectopic cervical thymus (15 children had bilateral lesions). Diagnosis was based on ultrasound in 98% of patients, magnetic resonance imaging in 18%, and computed tomography in 11%. Mean (SD) follow-up duration was 2 (2.2) years. Forty-four percent (51/115) of lesions involved the thyroid gland, 29% (33/115) were in the central neck but separate from the thyroid, 18% (21/115) had mediastinal extension, and 8% (9/115) involved the submandibular region. Location was unclear for two patients. Submandibular lesions were on average 12.4 cm³ larger (95% CI, 8.2, 16.6) than mediastinal lesions at diagnosis, P ≤ .001. Volume of thymic tissue decreased over time, from a mean (standard deviation [SD]) volume of 4.3 cm³ (9.2) at initial ultrasound to 2.7 cm³ (6.1) at final ultrasound (paired t-test, P = .008). Only two patients required surgery: one for compressive symptoms, and the other to rule out malignancy.

CONCLUSION

Ninety-eight percent of children with ectopic cervical thymus were managed conservatively without issues. We propose a classification system based on location to ease communication among clinicians and to help follow these lesions over time.

LEVEL OF EVIDENCE

4, case series Laryngoscope, 130:1577-1582, 2020.

[Ectopic thymus: A rare cause of neck mass in children]

INTRODUCTION

Ectopic cervical thymus (ECT) is a rare embryological abnormality in children. It can be revealed by a compressive neck mass mistaken for a malignant tumor. Through a new case of ECT, we review the embryopathogenesis, diagnostic difficulties and therapeutic features.

CLINICAL OBSERVATION

A 19-month-old girl presented a right cervical mass that quickly increased in size, causing intermittent dyspnea. The physical examination objectified a 6-cm, soft and compressible, painless right cervical tumefaction, extending from the mastoid area to the ipsilateral supraclavicular fossa. The diagnosis suggested based on CT was a cervicomediastinal cystic lymphangioma. The diagnoses discussed based on MRI were a collection of necrotic lymphadenopathy, rhabdomyosarcoma or neurofibroma debris. The mass was surgically excised through a laterocervical incision. A whitish multilobular tissular mass was found, adherent to the neurovascular axis of the neck. Pathological examination concluded in normal ectopic thymus tissue. The postoperative course was uneventful.

CONCLUSION

Although ECT is a rare benign anomaly, it should be considered as a possible cause of a neck mass in children. Surgery is the curative treatment. Before surgery, the presence of a mediastinal thymus must be confirmed to avoid the risk of a total thymectomy in children. MRI is helpful in delineating thymic ectopia compared to the mediastinal thymus.

A novel surgical management of hypopharyngeal branchial anomalies

OBJECTIVE

To review our experience treating hypopharyngeal branchial anomalies utilizing an open transcervical approach that: (1) includes recurrent laryngeal nerve (RLN) monitoring and identification if needed; (2) resection of tract if present; and (3) a superiorly based sternothyroid muscle flap for closure.

METHODS

A retrospective chart review was performed to identify all patients at a tertiary level children's hospital with branchial anomalies from 2005 to 2014. The clinical presentation, evaluation, treatment and outcome were analyzed for those patients with hypopharyngeal branchial anomalies.

RESULTS

Forty-seven patients who underwent excision of branchial anomalies with a known origin were identified. Thirteen patients had hypopharyngeal branchial anomalies. Six of these patients were treated by the authors of this study and are the focus of this analysis. All six underwent an open transcervical procedure with a sternothyroid muscle flap closure of a piriform sinus opening over a nine year period. Definitive surgery included a microlaryngoscopy and an open transcervical approach to close a fistula between the piriform sinus and neck with recurrent laryngeal nerve monitoring or dissection. A superiorly based sternothyroid muscle flap was used to close the sinus opening. There were no recurrences, recurrent laryngeal nerve injuries or other complications from these procedures.

CONCLUSIONS

This study supports complete surgical extirpation of the fistula tract using an open cervical approach, recurrent laryngeal nerve monitoring or identification, and rotational muscle flap closure to treat patients with hypopharyngeal branchial anomalies.

Sonographic appearance of intrathyroid ectopic thymus in children

PURPOSE

The aim of this study is to report the common location of intrathyroid ectopic thymus and describe the corresponding sonographic appearances in children.

METHODS

We retrospectively reviewed clinical data and neck or thyroid ultrasonography (US) findings in children from January 2003 to May 2010. Intrathyroid lesions showing hypoechogenicity with multiple linear echogenic branching structures or punctate echogenic foci were considered intrathyroid ectopic thymus. US features of the lesions (location, side, size, and shape) and the indication for US were recorded.

RESULTS

A total of 5,414 neck or thyroid US examinations were conducted in 3,195 children. We found 15 lesions that were suspected of being intrathyroid ectopic thymus in 12 patients (0.4%), four boys and eight girls, with a mean age of 6.4 years. The lesions were unilateral in nine patients and bilateral in three patients. All the lesions were located at the mid to lower portion of the thyroid. The long-axis diameter of the lesions ranged from 0.7 to 2.2 cm (mean diameter: 1.5 cm). All lesions had a fusiform shape with well-defined margins.

CONCLUSIONS

The possibility of intrathyroid ectopic thymus should be considered when a mid- to low-lying intrathyroid lesion with a fusiform shape with multiple linear or punctate internal echoes is detected on US in children.

Management of Congenital Third Branchial Arch Anomalies: A Systematic Review

OBJECTIVE: To systematically review the existing literature on third branchial arch anomalies and suggest guidelines for their management.

DATA SOURCES: We searched PubMed, Medline, and Embase using Scopus, and collected additional publications cited in bibliographies. We included all English-language articles and all foreign-language articles with an English abstract.

REVIEW METHODS: Two investigators reviewed all cases explicitly identified as third arch anomalies or meeting anatomical criteria for third arch anomalies; they assessed presentation, diagnostic methods, intervention, and outcome.

RESULTS: We found 202 cases of third arch anomalies; they presented primarily on the left side (89%), usually as neck abscess (39%) or acute suppurative thyroiditis (33%). Barium swallow, direct laryngoscopy, and magnetic resonance imaging were the most useful diagnostic tools. The recurrence rate varied among the treatment options: incision and drainage, 94 percent; endoscopic cauterization of the sinus tract opening, 18 percent; open-neck surgery and tract excision, 15 percent; and partial thyroidectomy during open-neck surgery, 14 percent. Complications after surgery appeared somewhat more frequently in children eight years of age or younger.

CONCLUSION: Third arch anomalies are more common than previously reported. They appear to be best treated by complete excision of the cyst, sinus, or fistula during a quiescent period. Repeated incision and drainage yields high rates of recurrence and should be avoided. Complications might be minimized by first initiating antibiotic treatment, delaying surgical treatment until the inflammatory process is maximally resolved, and by using endoscopic cauterization.

Solid cervical ectopic thymus in an infant

Cervical ectopic thymus presenting as a neck mass is rare in a neonate. Just more than 100 cases have been reported in the literature with less than 10% occurring in infants. We report a case of solid cervical ectopic thymus in an asymptomatic 2-month-old boy. We review the literature and discuss the embryology, pathophysiology, diagnosis, and management of an infantile ectopic thymus.

Ectopic cervical thymic tissue: diagnosis by fine needle aspiration

Cervical thymic masses are congenital lesions that result from aberrant thymic migration during embryogenesis. Although most of these masses are asymptomatic, they may cause debilitating symptoms secondary to encroachment on adjacent aerodigestive structures. Preoperative diagnosis of ectopic thymic tissue is rare; most cases are clinically misinterpreted as branchial cleft remnants or cystic hygromas. Definitive diagnosis has relied on histopathologic examination in nearly all reported cases. However, the invasiveness of open incisional or excisional biopsy carries the risk of surgical and anesthetic complications. Inadvertent surgical thymectomy may result in cell-mediated immune deficiencies in infants and young children. The utility of fine needle aspiration is gaining wider acceptance in the diagnostic evaluation of neck masses. We describe an infant with an asymptomatic cervical thymic mass diagnosed by fine needle aspiration.

Congenital cysts and fistulas of the neck

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.

Cervical thymic anomalies

Because of its infrequent occurrence, cervical thymic tissue is rarely considered in the differential diagnosis of neck masses. Consequently, diagnosis is most often made by pathologic examination of the excised specimen. The preponderance of reported patients have been children and adolescents, typically asymptomatic. The clinical presentation, evaluation and surgical management of five new cases of cervical thymic anomalies ranging from infancy to adulthood are described. The authors also review the embryology and histopathology of these lesions and discuss their recommended approach to the evaluation and management of cervical thymic anomalies.

Congenital cystic masses of the neck: radiologic-pathologic correlation

Cervical congenital cystic masses constitute an uncommon group of lesions usually diagnosed in infancy and childhood. The most common congenital neck mass is the thyroglossal duct cyst. The diagnosis is easily established from the presence of a cystic lesion in the anterior midline portion of the neck. The vast majority of branchial cleft cysts arise from the second branchial cleft. They can occur anywhere from the oropharyngeal tonsillar fossa to the supraclavicular region of the neck. Cystic hygroma is the most common form of lymphangioma. In the neck, cystic hygromas are most commonly found in the posterior cervical space. They typically extend into adjacent structures without respecting the fascial planes. Dermoid and epidermoid cysts result from sequestration of ectodermal tissue. The floor of the mouth is the most common location in the neck. Cervical thymic cysts are very uncommon lesions and are found anywhere from the angle of the mandible down to the sternum. Laryngoceles are classified into internal, external, and mixed types and have a frequent association with laryngeal carcinoma.

Cervical thymic cysts: CT appearance of two cases including a persistent thymopharyngeal duct cyst

The differential diagnosis of cervical cysts in children includes common entities such as branchial cleft cysts, thyroglossal duct cysts, and cystic hygromas. Congenital thymic cysts are uncommon and often misdiagnosed as either branchial cleft cysts or cystic hygromas. However, they may have an appearance on CT that can be characteristic. The course of the descent of embryologic thymic tissue in the neck to the mediastinum indicates the potential site of deposition of an ectopic cervical thymic cyst. In a child, a cystic lesion that has an intimate relationship to the carotid sheath is likely to be a thymic cyst. Of the approximately 100 cases of vestigial cervical thymus or thymic cysts that have been reported in children, only 5 cases of a persistent thymopharyngeal duct cyst have been described [1-5]. In two of these five, the persistent thymopharyngeal duct cyst was demonstrated by CT [1,2]. We report one additional case of a cervical thymic cyst and one case of a persistent thymopharyngeal duct cyst both depicted by CT.