Plasmacytoma

Epidemiology

Plasma cell neoplasms can be grouped into three categories: multiple myeloma, plasmacytoma of bone, and extramedullary plasmacytoma. Extramedullary plasmacytomas account for approximately 20% of all plasma cell neoplasms, and 80% of these lesions are found in the head and neck. Plasmacytomas are most frequently seen in the upper airways such as the epiglottis, larynx, and nasopharynx but they have also been reported in the sinonasal cavity, clivus, and petrous apex. Plasmacytomas are most commonly seen in the sixth and seventh decades (mean age 60 years, range 28–74). These neoplasms have an 80% male preponderance. Approximately 30% of patients with extramedullary plasmacytoma will have systemic disease after 20 years.

Clinical Findings

Clinical findings depend on the size and site of the neoplasm. Upper airway involvement such as sinonasal lesions may produce nasal obstruction or bloody nasal discharge whereas laryngeal lesions produce hoarseness of voice. Diagnostic evaluation should include bone marrow biopsy, skeletal survey, measurement of urinary Bence Jones proteins, and quantitative measurements for κ and λ light chains.