Extragonadal germ cell tumour with the "burned out" phenomenon mimicking a retroperitioneal tumour of neurogenic origin.

OBJECTIVE To describe a case of retroperitoneal metastasis of a gonadal germ cell tumour with the "burned-out" phenomenon in a 35 year old patient with a suspected diagnosis of retroperitoneal tumour of neurogenic origin. METHODS With the clinical and radiological suspicion of retroperitoneal tumour of neurogenic origin the tumour was removed, via the retroperitoneal space. RESULTS Pathology showed classic seminoma with foci of atypical or anaplastic seminoma, confined to the tissue sample. After a genital examination showing no alterations, a scrotal ultrasound was requested. This revealed a badly delimited hypoechogenic mass with microcalcifications in the left testis and a heterogeneous echostructure in the right testis, with hypoechogenic areas and some microcalcification. Bilateral orchiectomy was performed, with a pathological study compatible with residual scar tissue in the left testicle and focal findings of germ cell neoplasia, with no intratubular seminoma in the right testis. CONCLUSIONS The suspicion of an extragonadal germ cell tumour with the "burned-out" phenomenon modifies the therapeutic attitude, which should begin with orchiectomy, followed by systemic chemotherapy and the surgery kept in reserve for those cases where residual malignant tissue persists.