Germ cell teratomas belong to nonseminomatous 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 postpubertal 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 postpubertal teratoma in 22-37% of cases. In scar associated teratoma (burn-out component), the metastasis rate is 66%. We reported a rare case of postpubertal teratoma in a 34-year-old male who presented with multiple liver masses initially. Liver biopsy revealed poorly differentiated adenocarcinoma probably from gastrointestinal (GI) tract. The upper and lower GI endoscopy were normal. Scrotal ultrasonography showed a hypoechoic cystic intratesticular lesion in the left testis. He underwent radical orchiectomy and the histopathology examination revealed postpubertal teratoma with burned out component. He 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.
- Post pubertal type teratoma is a malignant germ cell tumor in spite of exclusively well-differentiated mature component.
- The burned-out testicular tumor corresponds to a primary germ cell neoplasia that has partially or totally regressed.
- Approximately 50% of ‘burned out’ primary testicular tumors continue to harbor malignant cells and distant metastatic disease and can progress.
- Identifying testis as the origin of metastasis is crucial as there is a high chance for testicular relapse if orchiectomy is not performed.