Capsular-Invasive Papillary Carcinoma in a Thyroglossal Duct Cyst With No Synchronous Thyroid Malignancy: A...

Thyroglossal duct cyst carcinoma is an uncommon entity, and the optimal management strategy continues to be debated, particularly regarding the indication for total thyroidectomy in addition to the Sistrunk procedure. We report the case of a 38-year-old woman who presented with a painless midline neck mass. Imaging studies revealed a cystic suprahyoid lesion with a vascularized mural nodule containing calcifications, raising suspicion for malignancy. The patient underwent a Sistrunk procedure, and histopathological examination demonstrated a 1.5 cm intracystic papillary thyroid carcinoma with capsular invasion and negative surgical margins. Given these intermediate-risk features and abnormal scintigraphic findings, completion total thyroidectomy was performed; final pathology revealed no evidence of synchronous thyroid malignancy. The patient was referred for radioactive iodine therapy and remains under close follow-up without evidence of recurrence. This case highlights the importance of maintaining a high index of suspicion when mural nodules are detected within a thyroglossal duct cyst and underscores the need for individualized management based on histopathological risk factors and thyroid imaging findings.