Plasmacytoma is a frequent complication of multiple myeloma, either at diagnosis or within disease progression. The extramedullary disease confers a poorer prognosis and is biologically distinct with high-risk molecular and histological features, being resistant to conventional treatments. Radiation therapy remains the most effective treatment for extramedullary lesions to achieve local control. There are very limited data from randomized trials regarding the most appropriate systemic treatment. Case reports such as those presented here, as well as retrospective analysis of series, suggest that lenalidomide is an effective agent, in combination with dexamethasone, in this setting. Additional studies are needed to define the proper management of this condition.