A comparison of cytogenetics and histopathology in the malignant lymphomata.

The non-Hodgkin's lymphomata are characteristically near diploid with occasional examples having higher chromosome numbers. In contrast, about half the cases of Hodgkin's disease have chromosome numbers in the triploid range. Karyotypes in cases of Hodgkin's disease appear to be more deranged than those found in other lymphomata, even when the cells are in the diploid range. If karyotypically normal cells in the tumours represent some degree of host reaction, then this is most marked in Hodgkin's disease. Long arm deletions of chromosome 18 were identified in cells from 7/31 cases of non-Hodgkin's lymphoma; 5 were follicular and 2 contained both follicular and diffuse areas. The cases showing this deletion had a relatively good prognosis.