Colorectal Cancer in a Patient With Multiple Myeloma: A Treatment Dilemma.

Multiple myeloma (MM) is a malignancy of plasma cells characterized by the clonal proliferation of plasma cells that produce monoclonal immunoglobulins. While typically considered to be incurable, advances in treatment options have led to remarkable improvements in survival for these patients. Accumulating evidence suggests an increased risk for the development of a secondary primary malignancy (SPM) in these patients, perhaps as a result of myeloma directed therapy or as an effect of their underlying disease process. Here we present a case of a patient who was diagnosed with an SPM while undergoing palliative treatment for multiple myeloma and a treatment approach.