The Diagnostic and Treatment Challenges of Concomitant Mantle Cell Lymphoma and IgM Myeloma

It is rare for IgM multiple myeloma (MM) and mantle cell lymphoma (MCL) to coexist. Furthermore, it is challenging to demonstrate if there are two distinct types of neoplasia or if plasma cell differentiation of MCL is present. We discuss the case of a patient concomitantly diagnosed with MCL and IgM MM, and the subsequent diagnostic and management difficulties, and the positive treatment outcome. LEARNING POINTS: Due to the rarity of simultaneous multiple myeloma (MM) and mantle cell lymphoma (MCL), it is challenging to investigate a possible association. This report will draw attention to the condition's rarity, diagnostic and treatment hurdles, and hopefully inspire future research into therapeutic alternatives. Several recent developments indicate a bright future for treating refractory malignancies such as MM and MCL, such as the advent of chimeric antigen receptor T-cell (CAR T-cell) therapy.