Enteropathy-associated T cell lymphoma with brain involvement.

In a patient with enteropathy-associated T cell lymphoma. there was dissemination to the brain manifesting as an inflammatory lesion. the intestinal and brain lesions were studied using routine histology, immunohistochemistry, and polymerase chain reaction. The jejunum was involved by a multifocal large cell lymphoma associated with multiple inflammatory ulcers and villous atrophy with crypt hyperplasia of the intervening mucosa. The lesion in the brain consisted of necrotic tissue associated with an infiltrate of histiocytes and a relatively scant infiltrate of primarily small lymphocytes. The appearance was that of an inflammatory rather than a neoplastic process. The intestinal lymphoma cells were positive for T cell markers and contained cytotoxic granules detected with the TIA-1 monoclonal antibody. The small lymphocytes and occasional large cells in the cerebral lesion showed the same immunophenotype. DNA extracted from the intestinal lymphoma and the cerebral lesion showed identical monoclonal rearrangement of the TCR-gamma gene. Dissemination from enteropathy-associated T cell lymphoma may masquerade as an inflammatory lesion. Molecular analysis is useful in confirming the diagnosis.