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.