Cytogenetic findings and results of combined immunophenotyping and karyotyping in Hodgkin's disease.

Cytogenetic studies were performed in 21 cases of Hodgkin's disease. Fourteen cases revealed chromosomally aberrant clones which could be fully described in 12 cases. Two cases showed different unrelated clones and five cases only single cell aberrations. Recurrent breakpoints were 1p13/21 (six cases), 7q32/34 (five cases), 2p16/21 and 19p13 (four cases each), 4q25/28, 6q15/21 and 12q22/23 (three cases each). In two cases, a translocation between band 19q13 and band 14q11 or 14q32 was found. This finding may indicate that an unknown oncogene in 19p13 is activated by juxtaposition next to a T-cell receptor or immunoglobulin gene in 14q11 or 14q32, respectively. In eight cases each, total or partial monosomy 4 or 6 was present suggesting that tumor suppressor genes in 4q or 6q play a role in tumor development in Hodgkin's disease. Moreover, the aberrant clones lacked the Y-chromosome in men and the second X-chromosome in women in eight out of nine and in two out of three cases, respectively. Although different cell populations, especially T cells, showed mitotic activity in unstimulated short term culture, combined immunophenotyping and karyotyping unequivocally demonstrated that CD30 and CD15 positive Hodgkin and Sternberg-Reed cells represented the chromosomally aberrant clones.