Unusual chromosome abnormalities in primary central nervous system lymphoma.

Primary central nervous system (PCNS) lymphoma is a relatively rare disease. The Epstein-Barr virus (EBV) has often been implicated in the development of lymphomas. Few cytogenetic. studies on PCNS lymphomas have been reported. We describe here an unusual case of PCNS B cell lymphoma, centroblastic polymorphic type without coexistent immune deficiency. The cytogenetic study showed unusual abnormalities: t(l;9) (q25;p21); del (6) (q14 q25), trisomy 12 and in addition one clone with trisomy 7 and loss of chromosome X. We did not observe any chromosome 14 abnormality, which is more commonly reported in PCNS lymphomas.