Multiple myeloma involving the thyroid cartilage: case report.

Multiple myeloma involving the thyroid cartilage is exceedingly rare. We describe a patient with progressive airway obstruction due to diffuse involvement of the thyroid cartilage with multiple myeloma. CT revealed a conglomerate of calcifications of the thyroid cartilage. Additional classic lytic lesions of multiple myeloma were subsequently found in the bones, without associated calcifications. Calcified matrix in multiple myeloma involving the thyroid cartilage should now be included as an additional manifestation of extraosseous multiple myeloma.