Anaplastic Multiple Myeloma: An Aggressive Variant With a Poor Response to Novel Therapies.

Introduction Anaplastic multiple myeloma (AMM) is a very rare and aggressive morphologic variant of multiple myeloma with a historically poor prognosis. The term “anaplastic myeloma” is used to describe a plasma cell malignancy involving immature plasma cells of pleomorphic morphology with high-grade transformation and extramedullary involvement with large, poorly differentiated cells. Anaplastic morphology can be present at the initial diagnosis or can appear later in the disease course. Historically, this disease has been very resistant to chemotherapy. We have described 2 cases of anaplastic myeloma and the poor response to novel myeloma therapies.