Abstract
The coexistence of chronic myelomonocytic leukemia (CMML) and T-lymphoblastic lymphoma (T-LBL) is extremely rare. We report a 65-year-old female patient who presented with occipitocervical masses, fever, and night sweats for 1 month. Comprehensive examinations, including bone marrow aspiration, lymph node biopsy, flow cytometry, and molecular profiling, confirmed the diagnosis of CMML-1 combined with T-LBL. The patient achieved complete remission of T-LBL after VDCP chemotherapy (vindesine, daunorubicin, cyclophosphamide, and dexamethasone), but later relapsed and progressed to T-lymphoblastic leukemia (T-ALL). After unsuccessful salvage therapies, she was treated with venetoclax combined with the CHG regimen, which induced a second complete remission of T-ALL. Notably, the CMML remained indolent throughout the clinical course. This article, supplemented with a literature review, emphasizes the clinicopathological features, molecular mechanisms, and therapeutic strategies for this rare coexistence, thereby highlighting the importance of multidisciplinary collaboration and individualized management in rare hematologic malignancies.