Endocrine Abstracts

Introduction: Remnants of the fourth branchial arch are extremely rare with less than 100 cases reported in the literature and account for 1–4% of all branchial anomalies. These anomalies typically present as recurrent neck infections and/or abscesses or acute suppurative thyroiditis. We report a case of cyst of the 4th cleft revealed by a thyroiditis treated in our department.

Case report: A 6-year-old boy presented with recurrent neck swellings. During that time, he had a history of drainages, and attempted excisions, with recurrence of signs and symptoms after every intervention. Upon presentation to our clinic, he complained of painful swelling of his neck. Clinical examination revealed swelling of the anterior left neck that was tender to palpation and was approximately 5 cm. Ultrasound showed an irregular oval mass with polylobed contours, measuring 54 x 30mm, multi-loculated, of basi-cervical left location and pushing back the homolateral carotid axis and the left lobe of the thyroid which is of heterogeneous appearance. Computerized tomography scan showed a lobulated and multi-loculated mass of lateral and basi-cervical left location measuring 54x42x57 mm which compressed anteriorly the sternocleido-mastoid muscle as well as the left lobe of the thyroid. In the operating room, direct laryngoscopy revealed a sinus tract originating from the left side of the pyriform sinus apex; surgical exploration of the neck revealed the tract to pass through the hypopharyngeal wall, consistent with a fourth branchial anomaly. All scar from previous surgery, the ipsilateral thyroid gland, and the tract were completely mobilized. Postoperatively, the patient did well, and histopathology confirmed the presence of a sinus tract. The patient had an unremarkable postoperative course and has had no further recurrences.

Conclusions: Fourth branchial arch anomalies are rare and fascinating aberrations of fetal development that may present in many different ways such as thyroiditis. Combining a proper preoperative evaluation with careful surgical planning may result in the proficient eradication of these lesions, offering the patient relief from this source of recurrent infection.