PYOMYOSITIS ASSOCIATED WITH BACTEROIDES-FRAGILIS IN A PATIENT WITH MULTIPLE-MYELOMA

Pyomyositis is an infection of the skeletal muscle that is usually cau sed by Staphylococcus aureus. We report a 68-year-old Japanese woman w ho developed pyomyositis caused by Bacteroides fragilis Following trea tment for multiple myeloma. There are only two cases of pyomyositis as sociated with multiple myeloma in the literature. After receiving melp halan and prednisolone for five days, she developed multiple abscesses in the muscles of the right arm and thigh. Purulent exudate was aspir ated from the abscess, and B. fragilis was identified. This is the fir st case of B. fragilis pyomyositis. Magnetic resonance imaging aided t he diagnosis. Treatment consisted of surgical incision and drainage, w ith antibiotic administration. The immunosuppression caused by the mye loma and/or the chemotherapy presented a risk factor for the unusual i nfection observed in this patient.