IBCL-338: The Incidence of Composite Lymphomas: One Center Experience (Russia)

Abstract

Context: Composite lymphomas (CL) can occur simultaneously or sequentially and are of a particular interest in hematology. Objective: Approaches to the diagnosis and treatment of CL are complex with a full range of modern laboratory methods. Design: Analysis of cases of CL with histological and molecular features of these cases. Setting: Study setting can be used in hematological inpatient and outpatient departments. Patients: There were 37 cases of CL (M:F=2:1, median age 64 (38-83 years)). Interventions: All patients underwent a full range of diagnostic procedures, including histological, immunophenotypic, cytogenetic and molecular tests. Main outcomes measures: Study the combination types of CL. Results: Metachronous CL were observed in 17 cases; synchronous CL in 20 cases. Metachronous CL cases: the most common type of the second lymphoma was diffuse B-large cell lymphoma (DBLCL) with 58.8% and Hodgkin's lymphoma (HL) with 29.4%. In 30% of cases, DBLCL developed after HL therapy, and in 30% - after therapy of angioimmunoblastic lymphoma. The median time to development of the second lymphoproliferative disease (LD) was 6 years (range 7 mo - 40 yrs). Synchronous CL were observed in 55% of cases; the most common were the combination of chronic lymphocytic leukemia (CLL) with other LD, hairy cell leukemia (HCL) 54.5%, large granular lymphocytic leukemia, marginal zone lymphoma (MZL), follicular lymphoma, multiple myeloma, and fungal mycosis. Combination of HL with other LD was observed in 25% of cases (HL+MZL represent 60% of cases). It is not clear whether HL in this combination represents a clonal transformation from MZL cells or it is a secondary tumor that develops de novo after MZL treatment. Since common IGVH gene rearrangements and somatic mutation status could be detected for both types of cells; this may indicate that MZL and HL cell clones may originate from a single B–cell of the follicular germinal center. Conclusions: Careful examination is needed in atypical clinical course of lymphomas to exclude the second LD, including clonally related. CL are excellent models for studying the complex process of tumor cells evolution during the course of the disease. Treatment of CL is a non-trivial task and aims to control both diseases.