CD3(-)CD56(-HODGKINS-LYMPHOMAS WITH AN AGGRESSIVE-BEHAVIOR RELATED TOMULTIDRUG-RESISTANCE() NON)

CD56 expression has been reported previously in some non-Hodgkin's lym phoma (NHL) characterization. They principally involve the nascapharyn x, are related to Epstein-Barr virus (EBV), and may be classified as e ither T- or non-T-natural killer (NK) cells according to CD3/T-cell re ceptor (TCR) status at the genomic or protein level. The present study reports three cases of non-nasal NK-NHL with the following characteri stics: an agressive clinical behavior, heterogenous morphological data evoking pleomorphic T-cell malignant lymphoma, a non-T-NK phenotype u sing flow cytometry, and immunochemistry. The three cases were CD56(+) without membrane expression of specific T markers (CD3, CD5, and TCR) , Heterogenous results were observed concerning different antigens: CD 2, CD4, CD8, CD16, CD94, CD122, TiAl, perforin, and granzyme B. There was no evidence of detectable clonal TCR gene rearrangement with polym erase chain reaction. No NK activity was detected in the two tested ca ses, and no relation was found with EBV. Multidrug resistance investig ations suggest that agressive clinical findings could be related to MD R1 gene expression as confirmed by MDR1 mRNA detection, MDR1 gene prod uct (Pgp) expression, and a functional multidrug resistance study usin g rhodamine efflux by flow-cytometry. (C) 1997 by The American Society of Hematology.