A case of psoas abscess associated with diabetes mellitus (DM) is reported. The 64-year-old male patient with untreated DM was admitted to the hospital because of pain in the left lower side of his back and in the left leg. White blood cell, CRP, blood glucose and Hb_AIC were elevated. Abdominal ultrasonography demonstrated an ehco free space and abdominal CT scan revealed a low density area with un irregular border in the left psoas muscle, indicative of psoas abscess. Ultrasonography-guided percutaneous drainage was performed and thick, white pus was obtained. Group B β-Streptococcus was detected by culture. The patient's condition was improved with the pus drainage, administration of antibiotics and treatment of diabetic status by intermittent insulin injection, but a hard mass developed subsequently in the left groin region. Pus that was similar to that previously drained from the psoas abscess was also collected by an incision of the mass. The amount of pus drainage gradually decreased over the course of days, and the patient was discharged from the hospital.
Though the process of infection and the development of the abscess were unclear in this case, they seemed to have been induced by advanced DM as a fundamental complication.