局所腫瘍摘除により治療し得ている傍尿道部より発生した再発性近位型類上皮肉腫の1例

Abstract

62歳男。会陰部無痛性腫瘤を主訴とした。CT, MRIで会陰部, 尿道近傍右側に22×13mmの石灰化を伴う腫瘤を認め, 摘除術を施行した。病理組織学的に腫瘍は小型類円形細胞の密な増殖からなり, 胞巣状構造を認め偽腺管構造や偽乳頭状構造もまれに認めた。免疫染色ではサイトケラチンとEMA陽性, S-100蛋白とLCAは陰性であったことから, 近位型類上皮肉腫と診断した。初回手術より2年7ヵ月後, 手術創部直下に再度腫瘤が再発し徐々に増大したため, 初回手術より3年4ヵ月後に再発腫瘍的除術を施行した。病理学的に前回の近位型類上皮肉腫と同様の組織像であった。2度目の局所再発後1年経過現在は再発を認めていない。

Proximal-type epithelioid sarcomas are rare soft tissue neoplasms occuring in the soma or thigh and often repeat recurrence and metastasis. We present a case of locally recurrenced proximal-type epithelioid sarcoma that could be treated by regional excision alone. A 62-year-old man visited our institute for a growing mass in the perineal region. Computed tomography (CT) showed a periurethral tumor 22 x 13 mm in diameter in the perineal region. The tumor was excised regionally, and the pathological examination with immunohistochemical staining revealed that the tumor was proximal-type epithelioid sarcoma. Local recurrence of the tumor occurred 2 years 7 months later without any metastatic lesion, and regional excision was performed again. Pathological diagnosis was proximal type epithelioid sarcoma and it was identical to the primary tumor. The patient is free of the disease 1 year after the second surgery of the tumor.