CYTOLOGICAL STUDIES OF TUMORS. 42. CHROMOSOME ABNORMALITIES IN MALIGNANT LYMPHOMAS OF MAN

Abnormal chromosomes in histocytic lymphoma

Five of six diffuse histocytic lymphoma patients had chromosomal abnormalities. Four had abnormal clones; three, a large acrocentric chromosome (LAC); and one, an abnormal large submetacentric chromosome (LSC). The LAC was a 14q+ and the LSC, a 4q+. Although no cytogenetic abnormality was found in a normal lymph node of a patient whose diseased lymph node had an LAC, abnormal chromosomes were seen in three patients with normal morphological bone marrow and in two peripheral blood specimens with a normal differential count. Since staging is important in aiding the clinician to select the type of treatment in this disease, it is recommended that cytogenetic studies in all biopsied tissues should be done as part of an overall diagnostic procedure in patients suspected of this disease.

Karyotype analysis of B-lymphocytes transformed by Epstein-Barr virus in 21 patients with B cell chronic lymphocytic leukemia

The karyotypes of 21 patients with chronic B cell leukemia were studied using lymphoblastoid cell lines obtained with the aid of the Epstein-Barr virus. Ten patients had a normal karyotype and eleven patients, an abnormal. There is no single characteristic anomaly, but certain types were more frequent, i.e., 14q+ as a result of a translocation 11;14, trisomy 12, and an isochromosome 17q. Abnormalities in these same three chromosomes have been found in other hematologic malignancies. It is postulated that loci with control cell proliferation are present on chromosomes 12, 14, and 17.

A new characteristic karyotypic anomaly in lymphoproliferative disorders

A new characteristic chromosome anomaly t(11;14)(q14;q32?) in lymphoproliferative disorders (LPD) is described in 4 cases. The extra material was found on a "14 chromosome (14q+) and belonged to the long arm of one "11 chromosome in 3 cases and to the long arm of a "14 in the other case. These cases confirm that the distal end of chromosome 14q may function as a "receptor site," according to the hypothesis of Kaiser-McCaw et al. and also tend to indicate that chromosome "14 may not be unique in showing so-called "donor" and "receptor sites," and that other chromosomes, in casu chromosome "11, may behave similarly.

Association of a chromosomal abnormality with lymphocytes having both T and B markers in a patient with lymphoproliferative disease

The lymphocytes of a patient with leukemic lymphosarcoma were found to have an unusual surface phenotype in that they bound both sheep erythrocytes (a T cell marker) and complement-coated erythrocytes (a B cell marker) but lacked other B cell surface characteristics. Marker chromosomes were present in these cells, but not in other, phenotypically normal cells from the same patient. This case may provide a clue to the chromosomal origin of some lymphocyte surface markers in man.

Chromosomes and transformation of lymphocytes in lymphoproliferative disorders

In chronic lymphocytic leukaemia the majority of circulating lymphocytes which responded to phytohaemagglutinin in vitro were found to have normal karyotypes. A minor population of cells in patients treated with chemotherapy had an increased number of chromosomal rearrangements as compared with cells from normal controls and untreated patients with chronic lymphocytic leukaemia. Probably bonemarrow and lymph-node cells also had a normal karyotype.In the other lymphoproliferative disorders the peripheral blood lymphocytes had either normal karyotypes or chromosomal abnormalities attributable to treatment, even in those cases where the tumour cells of involved lymph nodes were known to have abnormal karyotypes.It was possible that circulating tumour cells were present in one case.