副睾丸原発胎児性横紋筋肉腫の1例

A CASE OF THE EPIDIDYMAL RHABDOMYOSARCOMA

Ⅰ．緒言

　横紋筋肉腫は在来横紋筋の存在する骨格筋に発生する同所的腫瘍と，横紋筋の存在しない部位に発生する異所的腫瘍がある。前者は成人に多く，後者は小児に多いことが知られており，幼小児では大部分が頭頸部，ついで泌尿生殖器に好発するが，発生臓器を明らかにできるものは少ない。

　私どもは副睾丸原発の小児胎児性横紋筋肉腫の1例を経験したので報告し，いささか文献的考察を加える。

An 8 year-old boy developed an asymptomatic hen egg-sized swelling of the right testicular region. A hard tumor was found to be situated over the testis at surgery and it appeared well delineated from the latter. On sections, the testis appeared to be free from neoplastic invasion and the epididymis was not identified.

The testis was within normal range by histology. Histology of the tumor was consistent with that of an embryonal rhabdomyosarcoma with some differentiation. Most of the neoplastic cells had uniform nuclei of oval shape and scanty cytoplasm, some of which showed myxomatous degeneration.