[Septic arthritis due to Bacteroides fragilis in a patient with non-Hodgkin lymphoma and mixed connective tissue disease].

We present a 53 year old woman with pre-existing mixed collagen tissue disease who developped highly-malignant non-Hodgkin lymphoma and 2 years later had left groin abscess, then septic tenosynovitis of the left ankle, septic artrhritis of the right shoulder and purulent tenosynovitis of the right hand. Bacteroides fragilis was identified in synovial fluid drawn from the right shoulder, in blood cultures and in culture of a central venous catheter tip. The primary infection site is presumed to have been the abdominal cavity, and the presence of an indwelling central venous catheter the reason for recurrence of infection. We treated her empyrically with intravenous ampicillin/sulbactam and clindamycine then oral metronidazol until definite resolution of the infection. Septic artrhritis due to Bacteroides fragilis is a rare entity mainly occurring in immunocompromised patients, as shown in this case.