睾丸類表皮嚢腫の1例と本邦症例の文献的考察

EPIDERMOID CYST OF THE TESTIS:REPORT OF A CASE AND REVIEW OF THE LITERATURE

緒言

　睾丸の良性腫瘍は稀で，睾丸腫瘍の2〜4％を占めるのみで，他は悪性である^1）。睾丸の良性腫瘍としては被膜性線維腫，神経線維腫，海綿状血管腫，類皮嚢腫，類表皮嚢腫，間質細胞性腫瘍などが知られている^2）。

　一方，類表皮嚢腫は四肢末端などの皮下，脳，骨，筋肉，卵巣などに比較的しばしば認められる良性腫瘍である^3）。しかし，睾丸内の発生は稀で，睾丸腫瘍の約1.2％^4）であるという。睾丸腫瘍の発生率は人口10万に対し2.1〜2.3^5）であるから，睾丸類表皮嚢腫の発生率は人口10万に対し0.025〜0.028と推定される。

A 15-year-old high school boy was seen with the complaint of a painless nodule in the right scrotal content. Physical examination revealed a small, well defined mass in the upper portion of the right testicle. It was slightly irregular and stony hard. The epidermoid cyst was suspected preopera-tively. Since the encapsulated mass with thin wall was observed after incising the tunica albuginea, only the mass was removed. Histological findings revealed that tumor wall was stratified squamous epithelium with cholesterin-crystals and calcification, and that tumor contained layers of keratohyalin materials.