[CT and MR imaging of germinomas arising in basal ganglia and thalamus].

OBJECTIVE: To evaluate the role of CT and MR imaging in diagnosing germinomas arising in the basal ganglia and thalamus.
METHODS: MR imaging of 11 boys (ranging in age from 3-15 years with a median of 10.7 years) with germinomas arising from the basal ganglia and thalamus was reviewed retrospectively and the imaging findings were compared with the features of 86 germinomas in other regions. The tumors located at basal ganglia in 9 and at thalamus in 2. All diagnosis was proved operatively and pathologyically. Five cases were studied using both CT and MR, 4 were examined with MR and 2 with CT only.
RESULTS: In this series of 11 tumors, 9 were located in the basal ganglia and 2 in the thalamus. The shape of six tumors was global and 5 was lobulated. The cystic components or necrosis were intratumoral in 5 patients and hemorrhage in 4. Patchy enhancement was found in 9 patients and ring-enhancing lesions in 2. Tumor spread oppositely in 4 patients. Five patients demonstrated cortical atrophy ipsilaterally.
CONCLUSION: The germinomas arising from the basal ganglia and thalamus have sex, location and imaging characteristics. Therefore, it is possible to make preoperative diagnosis using CT or MR.