Persistent lymphocytosis with chromosomal evidence of malignancy.

An inappropriate, sustained and absolute lymphocytosis in a young man was investigated using technics which attempted to define the more detailed features of these cells and their T and B subpopulations. The results of the tests for lymphocyte RFC (E) and complement (EAC) rosette formation, immunofluorescence, in vitro phytohemagglutin (PHA) stimulation and 14C-cyclo-phosphamide binding assays, when evaluated in a combined and interrelated fashion, indicated that the lymphocytosis was mainly but not solely, due to an absolute elevation in circulating T lymphocytes. Moreover, an aneuploid cell line with 47 chromosomes, presumably T cells, also was detected in PHA-stimulated cultures. These data, associated with the patient's anemia, lymphocyte-infiltrated bone marrow, hepatosplenomegaly, pharyngeal lymphoid tumor and the clonal proliferation of lymphocytes bearing an abnormal karyotype, furnish evidence that the lymphocytosis is more than an unremitting leukemoid reaction and is potentially neoplastic. The detection of the chromosomal abnormality at this patient's age and point in disease may make him especially unique in that he could be a clinical prototype for other patients with lymphoreticular tumors which remain undetected at their onset.