Background. Multiple myeloma complicated by extramedullary plasmacytoma is an unfavorable variant of the disease. It remains unknown what triggers tumor transformation. The review presents literature data on the pathogenesis of extramedullary disease, as well as a clinical example of a comprehensive study of the tumor substrate.Aim. To study the molecular and biological characteristics of the tumor substrate of the bone marrow and extramedullary plasmacytoma using various research methods.Materials and methods. A 55-year-old patient was admitted to National Medical Research Center for Hematology with a diagnosis of multiple myeloma occurring with extramedullary plasmacytoma of the retroperitoneal space. dNA was isolated from samples of different localization (blood plasma, Cd138+ bone marrow cells, plasmacytoma and buccal epithelial cells). The profile of short tandem dNA repeats (STR) from the obtained samples was studied by multiplex polymerase chain reaction followed by fragment analysis. fluorescent in situ hybridization (fISH) of bone marrow Cd138+ cells was performed using various dNA probes. Comparative genomic hybridization on a microarray (arrayCGH) plasmacytoma dNA was also performed. The mutation profile of the KRAS, NRAS, BRAF genes was studied by Sanger sequencing in tumor samples of various localizations.Results. The induction therapy (vCd (bortezomib + cyclophosphamide + dexamethasone), vRd (bortezomib + lenalidomide + dexamethasone), daratumumab therapy) was ineffective, death occurred 4 months after the first clinical manifestations appeared. Comparison of STR markers of circulating cell-free tumor dNA (cfdNA), Cd138+ bone marrow cells, and plasmacytoma revealed the largest number of involved loci exactly in plasmacytoma’ dNA. A mutation in the NRAS gene was found only in plasmacytoma’ dNA. This indicates the presence of another clone of tumor cells in the extra-medullary plasmacytoma. Molecular karyotyping of plasmacytoma using the arrayCGH method revealed rearrangements of many chromosomes. 1p32.3 bi-allelic deletion, amplification of 1q21, 8q24/MyC rearrangements and del17p13 were confirmed by arrayCGH molecular karyotyping and fISH studies in bone marrow and plasmacytoma.Conclusion. A comprehensive molecular genetic study of the extramedullary plasmacytoma’ substrate is necessary to understand the pathogenesis mechanisms and, on this basis, to develop differentiated therapeutic approaches.

Aim.To evaluate the efficacy of DSP30 in combination with IL2 in cultivating blood cells/bone marrow/lymph nodes in chronic lymphocytic leukemia (CLL) patients to detect clonal abnormalities.Materials and methods.The study included 50 patients with CLL, all of whom underwent both chromosome banding analysis (CBA) (46 patients with DSP30+IL2 and LPS+TPA; 4 patients with only DSP30+IL2) and FISH with DNA probes to detect trisomy 12 and deletions of 13q14, 11q22 and 17p13.Results.Under cell cultivation with DSP30+IL2 and LPS+TPA, CBA was successfully performed in 41 (82 %) and 38 (83 %) patients. Chromosome aberrations were observed in 36 (72 %) and 15 (33%) cases, while a complex karyotype was detected in 13 (26%) and 5 (11%) cases, respectively. A significant difference was found between the number of metaphases with chromosomal abnormalities obtained by cultivation with DSP30+IL2 and LPS+TPA (V = 490.5, p < 0.05). CBA revealed balanced translocations in 6 patients, with the involvement of the IgH/14q324 locus being confirmed in 4 cases. Unbalanced translocations and various combinations of translocations were detected in 11 and 6 patients, respectively. In 5 cases, according to CBA, the results of 13q14, 11q22, 17p13 deletions identified by FISH were accompanied by balanced or unbalanced translocations in these loci. Unbalanced t(12;16)(q14;q23) — a case of partial trisomy — was detected only by CBA with DSP30+IL2.Conclusions.An abnormal karyotype was detected in CLL patients twice as more frequently under cultivation with DSP30+IL2 compared to LPS+TPA. CBA is an important method allowing the structure of chromosomal abnormalities to be specified and translocations to be identified. As a result, patients running the highest risk of CLL — those with a complex karyotype — can be singled out for selecting an optimal strategy of their management.

Introduction. 13q14 deletion is the most common chromosomal abnormality in chronic lymphocytic leukemia (CLL), and as the sole abnormality determines the most favorable prognosis of the disease. Using molecular genetic methods two subtypes of 13q14 deletion were identifi ed based on the size of the lost chromosomal material: small (type I) with the involvement of the D13S319 segment containing MIR15A/MIR16-1 and DLEU1 genes and large (type II) containing centromeric region of 13q14 involving RB1 gene. Data on the impact of type I and II deletions on the course of CLL are controversial.Aim — to evaluate the prognostic signifi cance of different variants of 13q14 deletion in CLL.Patients and methods. The study enrolled two cohorts of CLL patients. Cohort 1: 256 patients who were studied by FISH with DNA probes for detection of 13q14/D13S319, 11q23/ATM, 17p13/TP53 deletions, and trisomy 12 before immunochemotherapy. 101 patients with identifi ed 13q14/D13S319 deletion were analyzed with a DNA probe for RB1 locus for determination of deletion size (type I or type II). Cohort 2: 28 patients at different stages of the disease with deletion 13q14 detected by FISH were studied by using combination of standard and molecular cytogenetic methods (mFISH, mBAND, arrayCGH) to clarify the structure of 13q abnormalities.Results. In Cohort 1 chromosomal aberrations were detected in 75 % of patients: 13q deletion — 52 % (isolated — 36 % of all cases and 48 % of cases with deletion), 11q deletion — 19 %, +12 — 13 %, 17p deletion — 6 %. 13q14 deletion type I was detected in 56 %, type II — in 44 % of patients. Type II deletion correlated with the presence of 11q deletion (p = 0.05). Isolated deletions of type I and II were found in 61 and 39 %, respectively. Biallelic deletion was identifi ed in 12.7 % of patients with 13q deletion. Statistically signifi cant differences in OS were obtained in type I and II groups of patients with isolated 13q14 deletions: median OS was not reached and made 67.5 months, respectively, p = 0.05. In Cohort 2 structural abnormalities of chromosome 13 by conventional cytogenetic analysis (CCA) were identifi ed in 50 % of cases: 13q deletion — 11 cases; translocations involving 13q14 — 6 cases. In 5 cases with biallelic deletion identifi ed by FISH, 13q14 deletion by CCA was detected in two patients, and only in one allele.Conclusion. In general, 13q14 deletion is a cytogenetic factor of favorable prognosis for CLL but its structure is heterogeneous. Loss of tumor suppressor RB1 (type II deletion) negatively affects OS in patients treated with immunochemotherapy

In chronic lymphocytic leukemia, the risk of second tumors including hematological malignancies, with which the use of purine nucleosides and alkylating agents in treatment of chronic lymphocytic leukemia is most often associated, is significantly increased. Concurrent detection of this disease and various hematological tumors is a rare occurrence in hematological practice. Use of cytogenetic method or analysis allows to differentiate between 2 tumors and confirm differences in genetic abnormalities in different clones and on different levels of cell differentiation. This article presents a clinical case of simultaneous chronic lymphocytic leukemia and myelodysplastic syndrome with 2 clones with different cytogenetic abnormalities: partial trisomy of chromosome 12 and deletion of the long arm of chromosome 5 formed at different levels of cell differentiation.