Chronic Lymphocytosis with Lymphocyte Inclusions

The lymphocytes of a patient with chronic lymphocytosis contained unique inclusions. The inclusions, composed of cytoplasmic bundles of straight, tubular structures measuring 120 Å to 150 Å in diameter, were found in more than 90% of the lymphocytes in peripheral blood and bone marrow. Histochemical and immunofluorescent studies did not identify their composition, although the inclusions occurred within rough endoplasmic reticulum, suggesting that they were largely composed of protein. The disease has had a benign course for 9 years, and no defects of cellular immunity have been found. This new and rare clinical state is probably a form of chronic leukemia. It is easily recognized by the presence of unique lymphocyte inclusions.