Burned-out testicular tumor with retroperitoneal lymph node metastasis: a case report.

Background: A burned-out seminoma of the testis is an exceptionally rare clinical entity, with few reports found in the literature.

Methods: A case of burned-out tumor of the testis in a 31-year-old man is reported. The tumor presented as a retroperitoneal mass with histological characteristic of a seminoma. The testes on clinical examination were normal, and a suspicious lesion in the scrotum was only identified after ultrasound. Incision of the abdominal mass was decided, followed by orchectomy. Histological examination of the testis revealed a suspicious lesion with characteristics of spontaneous regression of germ cell tumors.

Conclusions: We describe one of very few cases worldwide, where spontaneous regression of a primary testicular tumor occurred after demonstration of retroperitoneal lymph node metastasis, a phenomenon known as burned-out seminoma, which is hard to recognize and incompletely characterized by physicians.