Endocrine Abstracts

Introduction: Papillary thyroid carcinoma can be found very rarely in a thyroglossal duct cyst (TDC) (1%), this cancer variant being the most common type. Although, most of the TDC develop in the midline of the thyroglossal duct (~70%), some cysts occur off midline, within 2 cm of the midline.

Case presentation: The female patient of 34-year-old presented at the Maxillofacial Surgery Department in October 2014, with a right submandibular painless neck mass at about 1.5 cm of the midline. The lump was discovered by the patient during pregnancy and increased in size gradually, reaching 2.5 cm at 5 months after birth. The clinical examination did not reveal any pathological aspects of the thyroid, nose, nasopharynx, or cervical lymph nodes. The ultrasound of the swelling revealed a pseudosolid mass near the hyoid bone, with thick capsule (4 mm), microcalcifications, and internal vascularity. The post-contrast computed tomography (CT) showed a 28/23 mm right submandibular mass, with complex heterogeneous composition, thick capsule, several microcalcifications in the solid component, no adenopathies, and no surrounding infiltration. After the mass was removed, histological examination established the diagnosis of papillary thyroid carcinoma. Subsequently, the evaluation of the thyroid gland (ultrasound, functional tests, and scintigraphy) detected no abnormalities. Up to now, the patient (still breastfeeding) has been closely monitored by clinical examination and thyroid ultrasound. Suppressive thyroxine treatment will be taken further into discussion.

Discussion and conclusions: As TDC in adults presents variable sonographic and CT appearance, the diagnosis poses sometimes difficulties. Moreover, the diagnosis can be hampered by the unusual off line location of the TDC. The management of the TDC carcinoma is still controversial, the recommendations ranging from only Sistrunk procedure to total thyroidectomy, followed by radioiodine and suppressive thyroxine treatment, or only suppressive doses of thyroxine.