ACUTE LEUKEMIA IN AN EMERGENCY IRRADIATED PATIENT WITH AN IDENTIFIED CYTOGENETIC CLONES IN THE BONE MARROW

The development of hematological malignancies is often associated with the influence of various genotoxic unfavorable factors, in particular, with the effect of ionizing radiation. The case report of the acute leukemia in a patient suffered from an accident at the Chernobyl nuclear power plant thirty years ago is presented. The average absorbed dose was estimated from the dicentrics frequency in peripheral blood lymphocyte culture and was 4.3 Gy. At a subsequent long-term clinical observation (27 years), moderate transient instability of hematological parameters was revealed: lymphocytosis, leukopenia and thrombocytopenia, which were associated with chronic persistent hepatitis. Three-color FISH-staining of chromosomes of cultured peripheral blood lymphocytes through 30.1-30.5 years after irradiation exposure demonstrated the level of translocations significantly in 42-54 times higher background value. In 2014, the patient underwent transurethral resection of the prostate in connection with prostate cancer. In May 2015, a course of radiation therapy with a total local dose of 35 Gy was conducted. In December 2015, there was a general weakness. Cytopenia was noted (RBC 3.56 x 10(12)/I, WBC 2.9 x 10(9)/I, platelets 90 x 10(9)/1). Diagnosis: acute myeloid leukemia, transformation from myelodysplastic syndrome. An abnormal complex clone was detected in 38% of metaphases by the mFISH-method along with other chromosome rearrangements.The patient died due to pneumonia in March 2017.