Multiple Myeloma with recurrent extramedullary replaces

Abstract

Multiple myeloma is a neoplasm of differentiated B cells, characterized by plasma cell proliferation resulting in end organ damage and immunosuppression.¹The majority of  clinical effects produced by myeloma can be attributed to proliferation of plasma cells in the marrow and secretion of paraprotein. ²In a small fraction of patients, presence of plasma cells is noted outside the marrow, termed extramedullary disease (EMD). Older studies have included bone related masses, and contiguous infiltration of plasma cells near marrow sites in this definition, but only soft tissue masses non-contiguous to the marrow are associated with adverse clinical outcomes, and it has been proposed that these should alone be included in the definition of EMD. ³Thus, the definition of Extramedullary disease has evolved to include soft tissue masses or plasma cell infiltration distant from the marrow, as a result of haematogenous  dissemination. ⁴ The incidence of true hematogeneously  disseminated plasmacytomas is much lower than initially  described, constituting only 15-30% of soft tissue masses initially labelled as Extramedullary disease. With the current use of PET/CT and MRI, true EMD is detected in 6-8% of patients at diagnosis. The incidence rises with disease progression, and upto 20% of patients develop    plasmacytomas at relapse. ⁵⁶We describe a patient who had extramedullary  disease at presentation and progressed with multiple extra medullary relapses. We review the implications of extra medullary disease in myeloma, with a highlight on post-transplant relapses and available therapeutic options.