Paradoxical development of a sarcoid-like reaction during successful chemotherapy for seminoma

Although the association between seminoma and sarcoidosis or a sarcoid-like reaction has been well recognized, a paradoxical case during chemotherapy for seminoma has not been reported. We report the first case of a sarcoid-like reaction that developed paradoxically during successful chemotherapy for recurrent seminoma. A 36-year-old Japanese man had recurrent seminoma in abdominal lymph nodes four years after left orchiectomy. Chemotherapy consisting of bleomycin, etoposide and cisplatin had reduced the abdominal mass, but mediastinal and bilateral hilar lymphadenopathy newly appeared. Surgical biopsy of the mediastinal lymph nodes and left nephrectomy and retroperitoneal lymphadenectomy revealed noncaseating granulomas only in mediastinal lymph nodes and confirmed complete remission of seminoma. Nine months later the thoracic lymphadenopathy had resolved spontaneously.