Shoulder Pain after Fall, Septic Shock, and Pyomyositis Associated with Breast Cancer Chemotherapy and Lymphedema

Background: As a symptom of pyomyositis, sepsis usually follows local inflammation signs. Here, we report pyomyositis with lymphedema of upper extremity in which septic shock and poor local findings initially presented during chemotherapy for breast cancer. Case Report: An 80-year-old woman presented with chronic right shoulder pain during chemotherapy for the recurrent disease. She had a history of postmastectomy lymphedema, diabetes mellitus, and repeated hyaluronic acid injections to the shoulder joint. The pain suddenly worsened with septic shock and no apparent local signs. Magnetic resonance imaging revealed myonecrosis, and no pus was yielded by ultrasound-guided needle aspiration. After 2 weeks of recovery by conservative medical management, surgical drainage was performed. Late formulated massive intramuscular pus showed severe neutrophil infiltration and myonecrosis. Conclusion: Pyomyositis can develop into septic shock with poor local signs. Myelosuppression after chemotherapy can cause myonecrosis without macroabscess, and magnetic resonance imaging was useful for the diagnosis of this condition. When unspecified local pain appears during cancer chemotherapy we should consider this disease, too