Most solitary extramedullary plasmacytomas are plasma cell tumors that tend to develop in mucosa-associated lymphoid tissues including the upper respiratory tract. We present a 43-year-old patient who was diagnosed with a solitary plasmacytoma in the lung. Primary plasmacytoma of the lung is exceedingly rare, and the treatment is surgical excision. This malignancy advances to multiple myeloma in a minority of patients. Multiple myeloma is a plasma cell malignancy that typically presents in the bone marrow.