Lymphomatoid granulomatosis with cerebral involvement. Light and electron microscopic study of a case.

Light and EM study of a case of lymphomatoid granulomatosis revealed a pleomorphic lymphoreticular cell infiltrate, angitis and necrosis with involvement of the brain, lungs, skin and right ear of a 30 year old woman. Cells comprising the infiltrate were classified as lymphocytoid, plasmacytoid, immunoblastic (histocytic) and phagocytic. A number of elements partook of the ultrastructural features of two cell types and were considered to be intermediate forms (plasmacytoid lymphocytes, lymphocytoid immunoblasts, and plasmacytoid immunoblasts). It is believed that the various cell elements form part of a wide spectrum in which transformation of cell types takes place by maturation. This suggests an immunologic process as the main pathogenetic factor in the development of LG.