[Subacute and chronic monocytic leukemia: diagnostic and clinical problems]

The authors report on 16 cases of either subacute (SMML) or chronic (CMML) myelomonocytic leukemia as well as chronic monocytic leukemia (CMoL). All these cases were oligoblastic and, according to their clinical course, they could be termed as smouldering leukemias. The chronic types affected mainly males. The diagnostic cytomorphological and cytochemical criteria are discussed. Erythro- and thrombocytopoiesis were distinctly less impaired than in acute leukemias (AL). The leucocyte count in the peripheral blood of the SMML cases was within the normal range. Hepato- and splenomegaly were markedly increased as compared to AL. According to our materials leukemic skin infiltrations were less frequent in CMoL, CMML and SMML than in acute monocytic leukemias. In each of the three types of leukemia discussed monocytic leukemic cells could be readily identified by cytochemical tests and usually showed fairly normal maturation. In accordance with these observations lysozyme levels in urine and serum usually were strongly increased. The patients in the CMML and CMoL groups showed a mean survival of more than 13 months (2 out of 7 are still alive), whereas the SMML patients survived an average of 8 months. Deaths were frequently due to advanced age rather than to leukemia. In other cases a terminal accumulation of blasts marked a transition to acute leukemia. During the smouldering phase of the disease no beneficial effect of combined chemotherapy could be noted. Supportive and symptomatic therapy might improve length and quality of survival.