Calcified iliopsoas abscess caused by Enterococcus faecalis.

A 67-year-old woman was referred to our department for the treatment of cryoglobulinemic vasculitis associated with primary Sjögren’s syndrome. One month after the initiation of immunosuppressive therapy, hemorrhagic rectal ulcers were observed and rectal resection was performed. Although a computed tomography (CT) scan obtained on admission was unremarkable (Picture 1), CT repeated two months after the initiation of immunosuppressive therapy revealed a calcified and gas-forming abscess in the right iliopsoas (Picture 2, arrow). Enterococcus faecalis was detected using a CT-guided biopsy. The empirical administration of biapenem (0.6 g/day) and clindamycin (1.2 g/day) for nine days was not effective; however, the patient was successfully treated using incisional drainage and the sequential administration of antibiotics [imipenem (1 g/day) and minocycline (200 mg/day) for three weeks, followed by ampicillin (6 g/day) for two weeks and amoxicillin (1.5 g/day) for one month] selected based on antibiotic susceptibility testing. Iliopsoas abscesses are classified as primary or secondary, depending on the presence or absence of underlying pathologies, such as gastrointestinal or genitourinary disease (1). Staphylococcus aureus and Mycobacterium tuberculosis are well-known causative organisms; however, infection with E. faecalis is rare, even in patients with gastrointestinal lesions (1, 2). For example, Enterococcus was detected in only one out of 99 (1%) CT-guided drainage procedures for deep intramuscular and musculoskeletal abscesses (2). However, this case demonstrates that E. faecalis can form calcified iliopsoas abscesses resembling those caused by M. tuberculosis.