Chromosome studies in patients with T-CLL chronic lymphocytic leukemia and expansions of granular lymphocytes.

Chromosome analyses were carried out in eight patients with lymphoproliferative disorders of mature T and NK cells. Three cases were characterized by an abnormal expansion of granular lymphocytes (GL), one by a lymphoma of GL with leukemic spread, and four by an OKT4-T-CLL. In four patients cytogenetic studies were performed on bone marrow cells; in seven patients peripheral blood lymphocytes were examined by either direct preparations or PHA-stimulated cultures. Six patients displayed a normal karyotype. Two cases belonging to the OKT4-T-CLL group had a chromosome number ranging from 44 to 47, with multiple numerical and structural clonal anomalies. Clonal anomalies could be a feature of patients with the more aggressive clinical course.