We experienced a rare case of psoas abscess due to acute appendicitis. A 61-year-old male was admitted to the hospital because of fever and right abdominal pain. On admission his abdominal findings were atypical for acute appendicitis. So he was treated conservatively under a diagnosis of diverticulitis of the colon. Thereafter the patient came to the hospital three times because of the same symptoms, which were successfully managed by conservative treatment. At the fifth admission with the similar symptoms which also lacked in typical findings for acute appendicitis, he was treated conservatively under a diagnosis of right sided diverticulitis of the colon. After that he became almost free from the subjective symptoms, but laboratory findings got worse. CT revealed a psoas abscess. Laparotomy was performed and a diagnosis of psoas abscesses due to acute appendicitis was made.
It is rare in recent years that the psoas abscess is formed following acute appendicitis. In the last one decade only one case has been reported on. This paper describes the clinical course and treatment of the case together with a review of the literature.