甲状舌管壁異所性甲状腺由来乳頭癌の1例

Thyroglossal Duct Carcinoma

I．はじめに

　正中頸嚢胞は甲状舌管の消失機転の異常が原因とされる先天性頸部腫瘤で，日常診療において比較的よくみら来る疾患である。一方正中頸嚢胞に癌腫を併発することは稀^1）であり，また嚢胞内に癌腫が原発することに否定的な見方^2）も存在する。今回われわれは甲状性舌管壁異所性甲状腺に由来したと思われる嚢胞状変性を伴う乳頭癌の1例を経験したので，若干の文献的考察を行い報告する。

A 24-year-old woman developed a mass in the anterior neck, and the mass increased in its size in two weeks. A well circumscribed and soft mass was palpated to the left of the midline below the hyoid bone. Computed tomography revealed a well circumscribed low-density mass which contained a slight high-density protrusion with marginal calcification. Ultrasonography showed a mixed type of the homogenous echo spikes and echo-free zone. A thyroid scan showed normal uptake and normal location of the thy-roid gland. A space-occupied lesion was not found in the thyroid. The mass was removed by Sistrunk's procedure. Histological examination showed papillary adenocarcinoma arising in the thyroglossal duct, but columnar or squamous ep-ithelium lining was not found. The patient's post-operative course was unremarkable for two months.

Since the thyroglossal duct carcinoma was rare, bibliographic review was shortly discussed and comments about the method of diagnosis and treatment was briefly made.