Solitary extramedullary plasmacytoma of the lung with rapid transition to multiple myeloma : A rare case report and brief literature review.

SEPs are an exceedingly rare form of malignancy with the potential for conversion to MM. Although the likelihood of transformation to MM in months is rare, we call for attention to the possibility of such transition and the clinical prognosis of patients with SEP. Prompt and aggressive treatment is essential, and this, to our knowledge, is the first case of conversion to MM in less than four months following the initial diagnosis of SEP of the lung.