電顕により確定診断された無色素性悪性黒色腫の1例

Amelanotic Melanoma

I．はじめに

　無色素性悪性黒色腫は近年提唱された疾患概念で，組織学的決め手は，プレメラノゾームの確認であるが，いずれにしても臨床上の診断は非常に困難である。

　われわれは右上顎洞に原発し，全体が浮腫状あるいは一部肉芽様の腫瘍で，最終的に電顕的検索により無色素性黒色腫と診断しえた1例を経験したので報告する。

　A 57-year-old man presented a right maxillary sinus tumor revealed no malignancy by repeated pathological examinations. Surgery was performed, and rhabdomyosarcoma was suspected. No recurrence was observed thereafter, but a granulomatous tumor appeared at the contralateral eyelid. The tumor was extirpated but it was reccurerd. Microscopic examination suggested amelanotic melanoma. Two months later tumor metastasis in the lung was suddenly occurred, and the patient died in two months. Electronmicroscopic examination revieled premelanosomes in tumor cells.