PRIMARY RETICULUM CELL SARCOMA OF THE BRAIN

This is a report of five cases of primary intracerebral reticulum cell sarcoma, three with cerebral and two with cerebellar localization. The one case studied anatomically (the other four were diagnosed by biopsy) was a frontal recurrence after an interval of seven years quiescence following surgery for a temporal tumour, treated post-operatively by radiotherapy. Postmortem examination of the viscera revealed no pathological changes. In all five cases the microscopic examination showed the tumour to be formed of a perivascular proliferation of cells having clear nuclei and one or more nucleoli, and associated with the formation of reticulin fibres. Electron microscopical examination revealed the multiplication of undifferentiated cells apparently starting the neoplastic transformation of the periadventitial elements. Both the microscopic and ultrastructural features corresponded to those of primary reticulum cell sarcoma of the brain.