腎原発の未分化神経外胚葉性腫瘍の1例

PRIMITIVE NEUROECTODERMAL TUMOR:REPORT OF A CASE

　症例は25歳女性で，腹部腫瘤を主訴として来院。腎癌の診断で右腎摘出術を施行。腫瘍は14×10×7cm大で，右腎の大部分を占めていた。組織学的に小型で円形の核を有し，胞体の乏しい腫瘍細胞が均一な増殖を示し，糖原を有するなど，ユーイング肉腫に酷似していたが，わずかに神経系への分化がうかがえた。本腫瘍の報告はきわめて稀であり，特に小細胞癌と鑑別する必要がある。

A rare case of primitive neuroectodermal tumor (PNET) occurring in the right kidney of a 24-year old female was reported. Grossly, the surgically removed kidney was subtotally occupied by large tumor, 14×10×7cm in size. Histologically, the tumor consisted of uniform proliferation of small round cells with round reticular nuclei and scant cytoplasms containing glycogens. Although the histological appearance was quite similar to that of Ewing's sarcoma, the tumor also exhibited neural differentiation, leading to a diagnosis of PNET. Differential diagnosis with small cell carcinoma was also discussed.