PRIMARY INTRACEREBRAL PLASMA-CELL GRANULOMA - A LIGHT, IMMUNOCYTOCHEMICAL, AND ULTRASTRUCTURAL-STUDY OF ONE CASE

A case of primary intracerebral plasma cell granuloma without meningeal attachment is presented. Histologically, the lesion showed two different patterns. At the center, it displayed the features of a benign fibrous histiocytoma. At the periphery, a mixture of polyclonal plasma cells, lymphocytes, and 'epithelial-like' cells was observed. Electron microscopy and immunocytochemistry confirmed the histiocytic nature of the 'epithelial-like cells'. The differential diagnosis and histogenesis of such a lesion are discussed.