Burned-out Post Pubertal Teratoma Presenting as a Liver Metastases in a 34-Year-Old Male

Germ cell teratomas belong to non-seminomatous germ cell tumors and account for 95% of malignant testicular tumors. Regarding the current World Health Organization (WHO) criteria, testicular teratomas are divided into prepubertal and post-pubertal subtypes based on patients' age. The term "burned-out testicular tumor" is a very rare condition referring to a regressed testicular tumor which presents with its metastases without any clinical finding in the testicle. Metastasis can be the presentation of post-pubertal teratoma in 22-37% of cases. In scar associated teratoma (burn-out component), the metastasis rate is 66%. We reported a rare case of post-pubertal teratoma in a 34-year-old male who presented with multiple liver masses initially. Liver biopsy revealed poorly differentiated adenocarcinoma probably of gastrointestinal (GI) tract origin. The upper and lower GI endoscopy were normal. Scrotal ultrasonography showed a hypoechoic cystic intratesticular lesion in the left testis. The patient underwent radical orchiectomy and the histopathologic examination revealed post-pubertal teratoma with burned out component. The patient underwent proper treatment and is still under follow up. As a result, in a young male patient who presented with a retroperitoneal mass or poorly differentiated carcinomas of an unknown primary site, using light microscopy and immunohistochemical profiling alone may be inadequate. Therefore, scrotal screening and physical examination of the scrotum and bilateral testis should be considered to exclude possibility of a metastatic progression from a testicular germ cell neoplasia.