Adult T-cell lymphoma. A case report with lymph node studies by monoclonal antibodies and ultrastructure.

A case of retrovirus-associated adult T-cell lymphoma studied by monoclonal markers and ultrastructure is reported. The patient, who was born in Jamaica and emigrated to Canada 9 years previously, had a 5-year history of asymptomatic lymphocytosis preceding the onset of rapidly progressive disease. The peripheral blood lymphocytes were predominantly pleomorphic small lymphocytes with a smaller population of transformed lymphocytes. The peripheral blood lymphocytes were typed immunologically as T-cells of helper/inducer phenotype. Immunological typing of the lymph node lymphocytes, performed on tissue sections, demonstrated a similar phenotype. Morphological study of the lymph node showed a diffuse lymphoma, encompassing a wide range of cell sizes, including giant cells. In view of the morphological heterogeneity of this condition, immunological and viral studies are recommended to confirm the diagnosis.