Pneumococcal septic arthritis of the knee in a patient with multiple myeloma.

Although most patients with multiple myeloma are predisposed to pneumococcal infections, such infections usually involve the respiratory tract or the meninges. Pneumococcal arthritis is rare in the general population and is unexpectedly even rarer in patients with myeloma. We believe this to be the first case of pneumococcal septic arthritis of the knee in a patient with myeloma.