Intracranial teratomas of the basal ganglia

Abstract

Intracranial teratomas other than those occurring in the pineal gland and at the suprasellar region are rare and few cases have been documented. Their putative origin from ectopic germ cells that have been segregated inside the brain during embryonic migration is controversial. We present the clinicopathologic features of three cases of primary intracranial teratomas affecting the left basal ganglia of three male patients aged 8,10 and 23. The radiological appearances were similar with large, multi-loculated cystic masses with calcifications situated at the left basal ganglia. Two tumours biopsied showed teratoma with germinoma and one case completely resected revealed mixed germ cell tumour containing teratoma with malignant transformation, choriocarcinoma and germinoma. Two patients had markedly raised pre-operative HCG levels. Treatment was complete excision in one case and biopsy followed by radiotherapy in two other cases. Two remained well 2 years and 18 months post-operation and one had a relatively short follow up. These cases suggest that i) intracranial teratomas of the basal ganglia possess distinct clinicopathologic features and ii) they have an indolent clinical behaviour in spite of the presence of choriocarcinoma, malignant transformation and the finding of raised preoperative HCG level.