Elevated Levels of Human Chorionic Gonadotropin-β, a Marker of Active Neurohypophyseal Germinoma, Detected by Immune Complex Transfer Enzyme Immunoassay

We report the usefulness of a highly sensitive immune complex transfer enzyme immunoassay (ICT-EIA) to detect human chorionic gonadotropin (HCG)-β and thereby the onset of neurohypophyseal germinoma in its active phase. A 14-year-old girl exhibiting arrested puberty was diagnosed with neurohypophyseal germinoma following observation for two years. This patient initially showed no signs of diabetes insipidus (DI). While ICT-EIA indicated concentrations of HCG-β higher than normal in cerebrospinal fluid (CSF) and serum, the results obtained with conventional methods were negative. ICT-EIA was also useful to assess the efficacy of treatment.