A Case of Synchronous Bone Marrow Chronic Myelomonocytic Leukemia (CMML) and Nodal Marginal Zone Lymphoma (NMZL).

BACKGROUND Leukemias and lymphomas can arise from myeloid or lymphoid stem cells. Combined myeloid leukemia and non-Hodgkin's lymphoma (NHL), either synchronous or metachronous, rarely occur in the same patient. This report is of a 67-year-old man with a synchronous diagnosis of both bone marrow chronic myelomonocytic leukemia (CMML) and nodal marginal zone lymphoma (NMZL), which a peripheral low-grade B-cell NHL. CASE REPORT A 67-year-old Caucasian man, who was a long-term cigarette smoker, presented with a five-year history of leukocytosis and cervical lymphadenopathy. He had no symptoms of night sweats, fever, or weight loss. Review of his medical records showed a progressively increasing leukocytosis with a peak of 58×109/L. Computed tomography (CT) imaging of the chest and abdomen showed lymphadenopathy, including enlarged cervical, axillary, mediastinal, and retroperitoneal lymph nodes. Bone marrow biopsy and histology showed CMML. Lymph node biopsy and histology showed NMZL. The patient was treated for NMZL with weekly intravenous rituximab infusions. Although his CMML was stable, the patient requested an evaluation for treatment with hematopoietic allogeneic stem cell transplantation (ASCT). At the time of this report, the patient remains asymptomatic. CONCLUSIONS The synchronous occurrence of bone marrow CMML and NMZL in a single patient is rare and may be attributed to a genetic mutation common to both. There are no current treatment guidelines for this group of patients, and treatment strategies should be individualized to provide an optimum outcome or symptomatic improvement.