INCIDENCE OF HOMOGENEOUSLY STAINING REGIONS IN NON-HODGKIN LYMPHOMAS

We report a series of 86 non-Hodgkin's lymphomas (NHL) studied cytogen etically in which two cases with a homogeneously staining region (HSR) located on chromosome 19 and on chromosome 1, respectively, were obse rved. The low incidence detected (2.3%) suggests that HSR are rare eve nts in NHL. An oncogenetic amplification study was performed with prob es for genes that are currently known to undergo amplification and wit h probes for two genes located on chromosome 19q (AKT2 and BCL-3). We detected no amplification except for AKT2 putative oncogene in the lym phoma in which the HSR was located on chromosome 19. Because amplifica tion of AKT2 putative oncogene has been detected in ovarian carcinomas bearing HSR and in this case NHL, we believe that this gene may be im plicated in the pathogenesis of other neoplasias in cooperation with o ther genes. Further investigation is needed to confirm the low inciden ce of HSR in NHL and the origin of the amplified material.