Aggressive Lennert's lymphoma: report of three cases in comparison to non-aggressive Lennert's lymphoma.

The present article describes three cases of Lennert's lymphoma exhibiting aggressive clinical courses. These cases were accompanied by disseminated intravascular coagulation (DIC) or hemophagocytic syndrome (HPS). These cases were compared to non-aggressive type of Lennert's lymphoma. Of the three cases, two demonstrated involvement of the liver and the other possessed bone marrow involvement. In one patient, while a lymph node biopsy revealed Lennert's lymphoma histologically, a liver biopsy obtained 2 months later revealed a high-grade large cell cytotoxic T-cell lymphoma. Two of these cases showed HPS and the other exhibited DIC. All patients died within 1 year of diagnosis, with the shortest survival period being 1.5 months. Immunohistochemically, lymphoma cells were CD8+, CD4-, granzyme B+, and T-cell intracellular antigen-1 (TIA-1)+, showing a cytotoxic T-cell phenotype. Two cases demonstrated positive reactivity for Epstein-Barr virus in lymphoma cells by in situ hybridization. These cases were compared with eight cases of non-aggressive Lennert's lymphoma. In comparison to non-aggressive disease, these three cases displayed a higher percentage of Ki-67-positive cells. In conclusion it was found that a subset of Lennert's lymphoma cases share common features with high-grade cytotoxic T-cell lymphoma, indicating that Lennert's lymphoma may be part of the spectrum of cytotoxic T-cell lymphoma.