The clinicopathological findings in 9 patients with germ cell tumors originating in the basal ganglia and thalamus are presented. The incidence of germ cell tumors of the basal ganglia and thalamus was 16.4% of all 55 cases of primary
intracranial
germ
cell tumors. These included 6 cases of germinomas and 3 cases of malignant mixed germ cell tumors (MGCT). The average age at diagnosis was 16.9 years (range 9.5-39 years). The sex incidence showed male dominance (8:1). The clinical course of
germinoma
in the basal ganglia and thalamus was slowly progressive and the average duration of symptoms before diagnosis was 29 months. The most common symptom and sign was hemiparesis and which was not normalized in all cases in spite of complete response
to
irradiation or chemotherapy. In case of germinomas, symptoms of increased intracranial pressure were found in only 1 case. Germinomas in the basal ganglia and thalamus had characteristic radiological findings different from that of pineal or
suprasellar
germinomas : irregular mixed density or signals.
Therapy consisted of stereotactic biopsy and irradiation in 6 cases, subtotal removal followed by irradiation and chemotherapy in 1 case, irradiation alone in 1 case and chemotherapy alone in 1 case. Of the 6 patients with germinoma, 5 are alive
and
disease free for 5 to 111 months after diagnosis (mean 57 months, median 62 months), but one patients died of recurrence on the primary site, temporal lobe, and cerebellum 87 months after cranial irradiation. Only 1 of 3 patients with malignant
MGCT is
still living 6 months after diagnosis, he showed complete response to chemotherapy and is now under maintenance of chemotherapy. There was no spinal seeding in our series. Because of the potential curability of germinoma and incomplete recovery
of
hemiparesis in patient with advanced germinoma in this region, early detection and treatment on the basis of biopsy, radiological finding and tumor marker study are essential in the management of germ cell tumors originating in the basal ganglia
and
thalamus.
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