Large cell anaplastic (KI-1) brain lymphoma of T-cell genotype.

Three cerebral lesions were neuroradiologically detected in a 63-year-old man without evidence of an extracranial neoplasm. The biopsy specimen from one lesion showed a large cell anaplastic lymphoma (LCAL). Immunohistochemically, tumor cells were positive for CD3, CD30, CD45RO, and HLA-DR. The polymerase chain reaction (PCR) of the rearranged T-cell receptor beta chain genome (TcR beta) derived from paraffin sections showed monoclonality. This case shows that primary cerebral T-cell lymphomas genotypically correspond to nodal T-cell lymphomas, a correspondence that has previously been demonstrated for the more common brain lymphomas of B-cell lineage.