MR imaging of intracranial germ cell tumors

MRI of 13 patients with intracranial germ cell tumor (GCT) was performed with a 1.5 T superconductive scanner. T1-and T2-weighted images (T1WI and T2WI) and Gd-DTPA-enhanced T1-weighted images (Gd-T1WI) were obtained. On T1WI and T2WI, five germinomas and one teratoma were homogeneously isointense with gray matter. Two germinomas with cystic component exhibited markedly hypointense and hyperintense areas, respectively. Three teratomas were heterogeneous on both sequences due to cystic portion, fat, and hemorrhage. Yolk sac tumor (YST) was isointense on T1WI and heterogeneous on T2WI. On Gd-T1WI, five germinomas and YST were homogeneously enhanced. All but one of the others were heterogeneously enhanced. There were increased AFP in YST and increased HCG in malignant teratoma. Differential diagnosis of GCT may be possible with MRI. However, tumor markers should be taken into consideration. (author)