Complete Metabolic Response to Rituximab-Bendamustine in an Elderly Patient with Rare Cyclin D1-Negative Leukemic Mantle Cell Lymphoma Mimicking Chronic Myeloid Leukemia: A Case Report dataset

Initial peripheral blood morphology misdirected clinical suspicion toward chronic myeloid leukemia. Diagnosis was definitively resolved via peripheral flow cytometry (distinct CD5+/CD23- profile) and bone marrow immunohistochemistry lacking Cyclin D1 expression.

This established a rare, Cyclin D1-negative MCL leukemic phase, featuring atypical non-FDG avid lymphadenopathy. She received six cycles of Rituximab-Bendamustine (R-Benda). Treatment was complicated by severe pruritus and stomatitis, requiring dermatologic intervention and dose delays.