[An Abnormal Alpha-Fetoprotein Fractionation Provides Additional Information: A Case of Retroperitoneal Germ Cell Tumor Accompanied by Liver Cirrhosis Type C].

Most of germ cell tumor is gonadal origin. However 5% of malignant germ cell tumors appear in extragonadal organs. Because extragonadal germ cell tumors (EGGCTs) are found anywhere on the midline such as pineal gland, mediastinum and retroperitoneum, the origin of this type of tumor is controversial. EGGCTs are often seen between childhood and young adult; an elderly patient with EGGCT is rarely met. Here we report a case that an abnormal alpha-fetoprotein (AFP) fractionation pattern was helpful for diagnosis of retroperitoneal germ cell tumor. A presenile man with hepatic cirrhosis caused by chronic hepatitis C showed an intraperitoneal tumor-like mass on computed tomography and thus hepatocellular carcinoma was suspected. A serological test re- vealed elevated total AFP level and AFP-L3%. The latter is the proportion of fucosylated AFP on the lectin-affinity based fractionation. Noticeably the fractionation pattern of AFP of this patient was abnormal, sug- gesting a diversity of lectin-affinity of AFP in germ cell tumors. This patient also showed an atypical in- crease in beta human chorionic gonadotropin (8hCG). We suggest the measurement of 6hCG for early differ- ential diagnosis of retroperitoneal germ cell tumor and hepatocellular carcinoma when an abnormal AFP frac- tionation pattern was detected in a patient with suspected hepatocellular carcinoma. [Short Communication].