散発性に発生した精巣上体乳頭状囊胞腺腫

A sporadic case of papillary cystadenoma of the epididymis

69歳，男性。左陰囊内腫瘤と違和感を主訴に受診，精巣上体腫瘤摘出術を施行した。術中迅速病理診断で腎淡明細胞癌の転移が疑われたため，高位除精術を追加した。術後の腹部CT検査では腎腫瘍を認めず，臨床経過，病理組織学的所見，画像所見を総合し，精巣上体乳頭状囊胞腺腫と診断した。また，フォン・ヒッペル・リンドウ病に特徴的な全身性の腫瘍性病変も認めず，散発症例と診断した。術後1年経過し，再発を認めていない。

A 69-year-old man presented with a 13-years history of left scrotal tumor complaining local discomfort. There were no pain nor fever. Physical examination revealed a thumb-sized-stony hard mass at the left epididymis. Ultrasonography showed a solid, 17 mm in diameter. tumor with high blood flow. The patient underwent a resection of the tumor of the epididymis. Because the tumor was suspected to be metastatic clear cell carcinoma based on an intraoperative frozen-section diagnosis, a left high orchiectomy was performed. Immunohistochemistry of the tumor revealed CD10（＋）, CA9（＋）and renal cell carcinoma marker（RCC）（－）. An abdominal CT scan, ophthalmoscopy and brain MRI after the operation showed no abdominal findings, including kidney tumors or other von Hippel-Lindau disease-related lesions. In light of the patient's history, and the histologic and radiographic findings, we diagnosed his condition as the sporadic form of papillary cystadenoma of the epididymis. The patient has not shown any recurrence or metastasis at 1 year after the operation.