Burned-Out Testicular Cancer: Really a Different History?

Two or more histological types characterize more than 60% of testicular germ cell tumors (GCTs). Burned-out testicular tumor refers to partial or complete histological regression of the primary testicular lesions. The most frequent GCT type involved in this kind of histological regression is choriocarcinoma, followed by embryonal carcinoma. To our knowledge, there are no cases of the burned-out phenomenon in teratoma. We report a case of a 19-year-old man presenting to our institute with a right testicular lesion, evidence of mediastinal and abdominal lymph node metastasis, and high levels of GCT serum biomarkers. After orchiectomy, the histopathological examination showed a mixed GCT: mature teratoma, immature teratoma, and histological features of testicular cancer regression (burned-out phenomenon). The patient underwent first-line chemotherapy (BEP regimen) which resulted in a complete instrumental and biochemical response after 4 cycles. Teratoma is considered a less aggressive type of GCT. In this particular case, metastatic disease seems to result from non-germ cell components which underwent early spontaneous regression.