Sarcoma

Abstract

Sarcomas of any type in the brain and spinal cord are most often secondary tumours resulting from local or metastatic spread, but in rare instances some examples may have a primary origin within the central nervous system. Such primary sarcomas may be primitive, polymorphic round-cell tumours, or more typical spindle-cell types, including leiomyosarcomas. Rhabdomyosarcomas may also occur as primary tumours, either taking origin within non-neoplastic leptomeninges or occurring within otherwise typical cerebellar medulloblastomas (“medullomyoblastomas”). Both the primary and the secondary sarcomas have ultrastructural appearances similar to those arising elsewhere in the body, and although there may be considerable variation between tumours of different soft tissue types, most spindle-cell sarcomas show some common distinguishing features at electron microscopic level.