対側精巣に精上皮腫を伴った精巣類表皮嚢胞

TESTICULAR EPIDERMOID CYST ASSOCIATED WITH CONTRALATERAL SEMINOMA

　症例は49歳，男性。主訴は顕微鏡的血尿。触診にて右精巣腫瘍が疑われ，入院となった。超音波，MRIにて左精巣にも嚢胞性病変を指摘されたが，悪性の可能性が低いものと判断し，まず右高位精巣摘除術を施行した。病理組織学的に精上皮腫と一部精細管内悪性胚細胞の診断を得た。対側は精巣温存を目的に腫瘍核出術を予定し，術中迅速病理検査にて類表皮嚢胞との診断であった。したがって，腫瘍核出術のみを施行し，厳重に経過観察する方針をとった。

We report a rare case of bilateral synchronous testicular tumors, right seminoma and left epidermoid cyst. A 49-year-old man was admitted to our hospital for the evalua-tion and treatment of right testicular tumor. MRI revealed the left cystic mass associated with right solid mass in the testicles. Initially high inguinal orchiectomy was performed. Pathological diagnosis showed seminoma with intratubular malignant germ cell, so the operation to the left cystic mass was performed under the suspicion of malignancy. Pathological study of frozen section revealed epidermoid cyst, therefore enucleation of the tumor was performed.