Early diagnosis in a case of atypically located germinoma: ¹H-MR-spectroscopy as a decision tool

CNS germinoma is a malignant germ cell tumor with a high potential for curative treatment. In MRI it mainly appears as contrast enhancing mass in the midline structures of the brain but it can also occur atypically located in the basal ganglia. We present the case of a 21-year-old patient suffering from psychiatric symptoms and a mild, right-sided hemiparesis. A MRI scan solely showed diffuse T2/FLAIR hyperintensity and mild atrophy around the left basal ganglia. As excessive diagnostics remained insignificant, ¹H-MR-spectroscopy was performed. Considering the previous diagnostics, increased choline, decreased NAA and increased Myoinositol suggested a malignant disease. Consequently, brain biopsy was performed, revealing a germinoma. In comparable, published cases a lack of evidence for a neoplastic disease usually leads to a severely delayed diagnosis. Our report shows for the first time, that this evidence can be obtained early with MR-spectroscopy and discusses the possibility of specific metabolic patterns.