A case of small cell carcinoma of the kidney.

A 47-year-old man had a retroperitoneal tumor measuring 18 cm in maximum diameter of the left kidney that was diagnosed with computed tomography (CT)-guided needle biopsy as small cell carcinoma. Microscopically, the tumor cells showed immunohistochemical reaction for neural cell adhesion molecule antibodies. This patient with advanced renal small cell carcinoma and multiple metastatic lesions was treated with the first-line combination chemotherapy of cisplatin, etoposide and ifosphamide, which showed a partial response of primary renal tumor and a complete response of liver metastasis, and with the second-line chemotherapy of cisplatin and irinotecan, which showed a complete response of Virchow's nodal metastasis. Thereafter, in spite of salvage chemotherapy of amurubicin hydrochloride for persistent and refractory renal small cell carcinoma, he died 32 months after the first presentation due to local progression. However, combination chemotherapy of these anticancer agents made his prognosis more favorable than we expected before treatment. The extrapulmonary small cell carcinomas are generally known to be more aggressive and malignant than the lung small cell carcinomas, and small cell carcinoma arising from the kidney is an extremely rare malignant neoplasm, with only 34 cases reported in the English or Japanese literature. The prognosis of renal small cell carcinomas is currently limited as compared with the lung small cell carcinomas, and therefore a cumulative investigation of a larger number of cases treated with multidisciplinary modalities including combination chemotherapy is necessary.