Follicular malignant non-Hodgkin's lymphoma with pronounced plasmacytic differentiation: a plasmacytoma-like lymphoma.

A case of follicular centroblastic-centrocytic lymphoma with an unusually pronounced plasmacytic component occurring in the gingiva and cervical lymph nodes of a 74-year-old male patient is described. Immunohistological analysis revealed a monotypic intracytoplasmic immunoglobulin pattern (IgM/lambda). The relation between follicular malignant non-Hodgkin's lymphomas and extramedullary plasmacytome is discussed. In the present case the tumour may represent the development of an autonomous plasma cell clone within a follicular centroblastic-centrocytic lymphoma.