Persistent Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia Due to Pelvic Pyomyositis and Abscesses With...

Pelvic pyomyositis can present a diagnostic challenge because of its anatomic location and nonspecific clinical manifestations. We report a case of a 39-year-old man with poorly controlled diabetes mellitus with neuropathy and bilateral foot ulcers who presented with 10 days of persistent methicillin-resistant Staphylococcus aureus (MRSA) bacteremia and progressive left hip pain. Transthoracic and transesophageal echocardiography and computed tomography (CT) of the abdomen and pelvis did not identify a definitive source of the persistent bacteremia. Contrast-enhanced magnetic resonance imaging (MRI) of the pelvis subsequently demonstrated multifocal intramuscular abscesses involving the obturator internus, gluteus minimus, and gluteus medius muscles, with extension through the greater sciatic notch and along the sciatic nerve. MRI established the diagnosis of multifocal deep pelvic pyomyositis. Surgical and percutaneous drainage were not considered feasible. The patient was treated with prolonged intravenous daptomycin, with subsequent clearance of bacteremia and clinical improvement. This case demonstrates an advanced stage of pelvic and sciatic infection involving the greater sciatic notch, highlighting the value of MRI in identifying and delineating a musculoskeletal source of persistent MRSA bacteremia when initial imaging was inconclusive.