[Spontaneous regression of testicular tumor]

We report the case of a 33-year-old man presenting with a retroperitoneal seminoma secondary to a testicular tumor which had completely and spontaneously disappeared (burned-out or shrinking seminoma). Ultrasound only showed a fibrous scar in the right testis. A careful study of the testicles should be considered in all male retroperitoneal tumor, even if they are asymptomatic, to exclude an occult cancer or more rarely a spontaneously involuted tumor. Testicular ultrasonography is today the gold-standard technique and any parenchymal echostructure abnormality should be verified histologically.