Chronic lymphocytic leukemia in the course of chronic myelocytic leukemia: evidence of independent clonal origin as shown by interphase fluorescence in situ hybridization and fluorescence-activated cell sorting

Coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma with antecedent chronic lymphocytic leukemia: a case report and review of the literature

BACKGROUND

Chronic lymphocytic leukemia and chronic myeloid leukemia are the most common types of adult leukemia. However, it is rare for the same patient to suffer from both. Richter's transformation to diffuse large B-cell lymphoma is frequently observed in chronic lymphocytic leukemia. Purine analog therapy and the presence of trisomy 12, and CCND1 gene rearrangement have been linked to increased risk of Richter's transformation. The coexistence of chronic myeloid leukemia and diffuse large B-cell lymphoma in the same patient is extremely rare, with only nine reported cases. Here, we describe the first reported case of concurrent chronic myeloid leukemia and diffuse large B-cell lymphoma in a background of chronic lymphocytic leukemia.

CASE PRESENTATION

A 60-year-old Saudi man known to have diabetes, hypertension, and chronic active hepatitis B was diagnosed as having Rai stage II chronic lymphocytic leukemia, with trisomy 12 and rearrangement of the CCND1 gene in December 2012. He required no therapy until January 2016 when he developed significant anemia, thrombocytopenia, and constitutional symptoms. He received six cycles of fludarabine, cyclophosphamide, and rituximab, after which he achieved complete remission. One month later, he presented with progressive leukocytosis (mostly neutrophilia) and splenomegaly. Fluorescence in situ hybridization from bone marrow aspirate was positive for translocation (9;22) and reverse transcription polymerase chain reaction detected BCR-ABL fusion gene consistent with chronic myeloid leukemia. He had no morphologic or immunophenotypic evidence of chronic lymphocytic leukemia at the time. Imatinib, a first-line tyrosine kinase inhibitor, was started. Eight months later, a screening imaging revealed new liver lesions, which were confirmed to be diffuse large B-cell lymphoma.

CONCLUSIONS

In chronic lymphocytic leukemia, progressive leukocytosis and splenomegaly caused by emerging chronic myeloid leukemia can be easily overlooked. It is unlikely that chronic myeloid leukemia arose as a result of clonal evolution secondary to fludarabine treatment given the very short interval after receiving fludarabine. It is also unlikely that imatinib contributed to the development of diffuse large B-cell lymphoma; rather, diffuse large B-cell lymphoma arose as a result of Richter's transformation. Fludarabine, trisomy 12, and CCND1 gene rearrangement might have increased the risk of Richter's transformation in this patient.

The coexistence of chronic lymphocytic leukemia and myeloproliperative neoplasms: a retrospective multicentric GIMEMA experience

Although the coexistence of chronic lymphocytic leukemia (CLL) and myeloproliferative neoplasms (MPN) has been sporadically reported in the literature, no systematic studies on this disease association are available. We retrospectively analyzed 46 patients affected by CLL/MPN referred by 15 Italian GIMEMA centers. The aim of this retrospective multicenter study was to define the following: clinico-biological characteristics, possible familiarity, clinical course of both diseases, and influence of MPN chemotherapy on the course of CLL. Among 46 patients, 30 patients were males, 16 patients were females; median age was 71 years. Only one case had familiar CLL. Myeloproliferative disorders consisted of essential thrombocytemia in 18 cases, polycythemia vera in 10 cases, chronic myeloid leukemia in 9 cases, primary myelofibrosis in 6 cases, and MPN/myelodysplastic syndrome in 3 cases. The lymphoproliferative disorder was diagnosed as monoclonal B-cell lymphocytosis in 8 patients and as Binet Stage A CLL in 38 patients. After a median follow-up of 49 months, 9 patients experienced progressive CLL and only 6 patients required treatment after a median of 57.5 months. The biological profile confirmed a subset of low-risk CLL. Twenty patients received chemotherapy for MPN without influence on the course of CLL: lymphocyte counts remained unchanged after 3, 6, and 12 months of treatment. This series is the largest so far reported in literature. The diagnosis of concomitant CLL/MPN is a rare event and lymphoproliferative disorders present a clinical indolent course with a low-risk biological profile. MPN therapy does not interfere with the prognosis of patients with CLL.

Identification of cell lineages involved by t(15;17) in acute promyelocytic leukemia by combined fluorescence activated cell sorting and FISH

Bone marrow cells from five patients with acute promyelocytic leukemia (APL) with t(15;17) were studied by a combination of fluorescence activated cell sorting and fluorescence in situ hybridization (FISH) to establish the cell lineage involvement of t(15;17). Interphase FISH demonstrated that the fusion gene (PML/RARA) was present in almost all abnormal promyelocytes. In one case, the translocation was demonstrated in both CD34+ and CD34- APL cells. The t(15;17) abnormality was not detectable in erythroblasts nor in T- or B-lymphoid cells. These results suggest that lymphocytes and erythroblasts are not clonally involved in APL, and that malignant transformation in some cases of APL may occur at the level of CD34+ cells.