MYC-Positive Diffuse Large B-Cell Lymphoma in Leukemic Phase at Presentation: A Diagnostic and Therapeutic Challenge.

Diffuse large B-cell lymphoma (DLBCL) in leukemic phase at presentation is a rare condition, and it can be challenging to differentiate from acute leukemia or other types of non-Hodgkin lymphoma. To obtain an accurate diagnosis immunophenotyping and cytogenetic analyses should be performed. Herein, we report a 54-year-old woman who experienced loss of consciousness and fever. Laboratory test results revealed leukocytosis, anemia, thrombopenia and hypercalcemia. Morphology of blood smear revealed two abnormal cell populations. However a specific diagnosis could not be made. Immunophenotyping showed two different populations, which was consistent with non-Hodgkin lymphoma. A fluorescence in situ hybridization (FISH) showed MYC and BCL2 rearrangements. Finally a leukemic DLBCL was diagnosed and immediately treatment with rituximab cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) was started. Due to MYC-positivity, lenalidomide was added to the therapy regimen. After treatment the patient achieved complete remission without any clinical sequelae, which is still ongoing after 4 years. Lenalidomide is an oral immunomodulatory drug that downregulates MYC gene and is commonly used in patients with multiple myeloma. Moreover, it can also be a promising therapeutic option for patients with MYC-positivity DLBCL presenting in leukemic phase. Copyright 2021, Bilgin et al.