A BENIGN FORM OF CHRONIC LYMPHOID LEUKEMIA

According to the classification of chronic lymphocytic leukemia (CLL) proposed by A. l. Vorobyev and M. D. Brilliant in 1983, benign CLL is a distinct form of CLL which is characterized by low level of absolute lymphocytosis, absent or mild peripheral lymphadenopathy, slow progre ssion. No specific therapy is needed. The paper presents clinical, mor phological and immunological analysis of 34 cases of benign CLL (17 ma les and 17 females, mean age 58 years). Patients were included in the study if they had lymphocyte count less than 30 000 and no significant growth of lymphoid tissue for at least 3 years. They were followed up from 3 to 24 years (11 years. on the average). The main features of b enign CLL are the following: no ''B'' symptoms, no essential enlargeme nt of the lymphoid organs, a stable low level of absolute lymphocytosi s, low prolymphocyte count in the blood smear (0.95% +/- 0.2), nodular or nodular-interstitial proliferation in the bone marrow. We failed t o find any cases with paraprotein secretion. There was immunophenotype typical for CLL in 91% of cases (CD19+, CD20+, CD23+, CD5+, EM+. CR1- /CR2+, sIg+-). None was positive for CD38 activation marker. One triso my 12 cases was detected by FISH method. 8 patients died so far, but n ot because of the tumor progression or transformation, median survival was 22 years.