Left-sided neck mass in a 30-year-old man imaged and aspirated, then excised by Sistrunk procedure and confirmed as thyroglossal duct cyst

Reports an adult thyroglossal duct cyst presenting as a left lateral neck mass rather than in the typical midline location. Thyroglossal duct cysts usually present as painless midline swellings in children; this report adds a documented adult lateral presentation and notes that adults are more likely to have infrahyoid, laterally placed and larger cysts. A single case report with preoperative examination, ultrasound, contrast-enhanced neck CT, FNAC and postoperative histopathology, forming a complete care pathway for this patient at the individual case level.

Imaging was central to diagnosis at an atypical site: ultrasound showed a 41×17×38 mm (about 14 cc) hypoechoic lesion in the left upper-mid neck with no internal vascularity and thin septa, while CT showed a cystic lesion below the hyoid and above the thyroid cartilage with fluid attenuation of about 31 HU, mild peripheral enhancement and dimensions of 41.9×23.4×33.6 mm. Shows that when a cyst deviates from the midline, its relationship to anatomical landmarks such as the hyoid and thyroid becomes a key clue to thyroglossal duct cyst, while ultrasound has limits in delineating deeper or complex lesions, making contrast-enhanced CT or MRI necessary in selected cases. Based on the descriptive ultrasound and CT findings in this case, cross-checked against typical imaging features of thyroglossal duct cysts described in the literature.

A Sistrunk procedure removed the cyst, tract and body of the hyoid together, the postoperative course was uneventful, and the gross specimen was a cystic tissue piece with attached hyoid measuring about 3×3.5×1.5 cm filled with thick white fluid and a wall 0.2–0.3 cm thick, with microscopy confirming a left thyroglossal duct cyst. Compared with simple excision, the Sistrunk procedure addresses the embryological tract and is cited as having low recurrence rates (<3–6%); here complete excision was achieved even though the preoperative diagnosis was not fully certain. A single case's surgical and pathological outcome combined with recurrence figures cited from the literature, representing individual experience set against published background.

Emphasizes that a newly appearing lateral neck mass in adults warrants careful evaluation to exclude neoplastic causes, and that thyroglossal duct cyst should be included in the differential. The differential for adult neck masses is broad, including thyroid nodules, lymphadenopathy, dermoid cysts, lymphangiomas, cystic metastases and malignancies; this report suggests thyroglossal duct cyst should be considered even at atypical locations. Based on this case's diagnostic pathway and a literature-based discussion, offering a clinical prompt rather than a controlled-study conclusion.

This applies to clinical settings where adults, particularly in their twenties and thirties, present with a new neck mass requiring differentiation between congenital cysts and neoplastic lesions; it suggests considering thyroglossal duct cyst when imaging shows a close relationship to the hyoid, and treating it with a Sistrunk procedure. It offers no additional evidence for typical pediatric midline presentations, already-diagnosed cases, or settings requiring large-scale comparative effectiveness data.

As a single case report, this cannot indicate how often adult lateral thyroglossal duct cysts occur or the relative effects of different management approaches; the text notes that malignant risk in adults is low (<1%) but rises with age, yet how this was assessed in this patient and for how long follow-up should continue is not developed; also, the title says 30 years old while the case description says 23, so readers should note this inconsistency when citing the age.