title: Retroperitoneal mass in a young man.
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D004407:Dysgerminoma / Q000175:diagnosis*; D006801:Humans; D008207:Lymphatic Metastasis; D008223:Lymphoma / Q000175:diagnosis; D008297:Male; D012186:Retroperitoneal Neoplasms / Q000175:diagnosis*; D013736:Testicular Neoplasms / Q000175:diagnosis*