[Primary cerebellar T-cell lymphoma.]

Primary central nervous system T-cell lymphomas are rare and have to be differentiated from reactive lesions. It is therefore essential to use all possible tools to establish the diagnosis, including immunohistochemistry, molecular genetic analysis, and/or cytogenetic methods. In this paper we present the case of a primary cerebellar T-cell lymphoma in a 50-year-old man; a clonal T-cell receptor gene rearrangement was documented. After two cycles of methotrexate therapy the patient developed Pneumocystis carinii-induced pneumonia, dying 10 weeks after his diagnosis. The autopsy did not reveal any residual tumour.