Infectious Lymphadenosis

MONG the features of infectious lymphadenosis (‘ ‘mononucleosis’ ‘) which help to distinguish it from acute lymphatic leukemia is the lack of reduction in both red cells and platelets. Conversely, the association of well-defined anemia and/or thrombocytopenia with a marked degree of lymphocytosis in which abnormal lymphocytes are conspicuous, almost certainly indicates acute leukemia. The present case report deals with an exception to this rule. A young woman with severe purpura hemorrhagica was found to have generalized lymphadenopathy and a marked lymphocytosis. Although the clinical picture appeared to be that of acute lymphatic leukemia, the character of the lymphocytes suggested infectious mononucleosis; this was confirmed by a strongly positive heterophile agglutination. When the patient’s bleeding became uncontrollable, splenectomy was performed and was followed by prompt recovery. The splenic histology was that of a reactive hyperplasia and that of adjacent lymph nodes was characteristic of infectious mononucleosis. This case is of interest not only because of its rarity, but because it brings up anew the diagnostic features of infectious mononucleosis, the question of “hypersplenism” and its relationship to thrombocytopenia, and the lymphocytosis observed in a number of cases of idiopathic thrombocytopenic purpura.