Seyed Alireza Emamian, Presenter: Nothing to Disclose

Gilbert Vezina MD, Abstract Co-Author: Nothing to Disclose

Magnetic resonance spectroscopy (MRS) is considered a useful adjunct in differentiation between tumor and tumor like conditions. As a generally applicable rule, neoplastic conditions demonstrate high choline and low N-acetyl aspartate. The purpose of this presentation is to demonstrate that central nervous system (CNS) germinoma is an exception to this rule.

Three male patients (9-11 years old) with CNS germinoma. Magnetic resonance imaging (MRI) and MRS were performed in all patients.

In all patients, the MRS failed to demonstrate elevated choline. In one case, the germinoma was located in the basal ganglia and demonstration of normal choline level favored non-tumoral differential diagnostic possibilities. Follow-up biopsy showed germinoma. In the other two cases, the typical location in the pineal region and characteristic imaging features of the lesions outweighed the MRS finding of non-elevated choline and biopsy proved the lesion to be a germinoma.

1) Lack of elevation of choline on MRS in an enhancing parenchymal lesion does not exclude possibility of germinoma.2) Lack of elevation of choline on MRS in an enhancing tumor in pineal region favors diagnosis of germinoma rather than a primitive neuroectodermal tumor (PNET).

Emamian, S, Vezina, G, CNS Germinoma Does Not Exhibit Elevated Choline.  Radiological Society of North America 2004 Scientific Assembly and Annual Meeting, November 28 - December 3, 2004 ,Chicago IL. http://archive.rsna.org/2004/4406448.html