A rare case of extramedullary plasmacytoma of the paranasal sinuses.

Plasmacytoma is a rare malignant tumor originating from plasma cells either located in the bone marrow (known as solitary bone plasmacytoma or SBP) or from outside the bone, usually arising from the mucosa (known as extramedullary plasmacytoma). Extramedullary plasmacytoma (EMP) in the head and neck region is extremely uncommon, and therefore this case involving the paranasal sinuses is reported for its rarity and to demonstrate the importance of imaging in the diagnosis and follow-up of the disease. Both pathologies can progress to multiple myeloma, a much more common manifestation of the continuum of plasma cell neoplasms.