Primary tuberculous psoas abscess as a postpartum complication: Case report and literature review

Primary psoas abscess is an unusual clinical entity rarely encountered in the postpartum period. Only seven cases have been reported to date. Here, we present a woman with a primary psoas abscess caused by Mycobacterium tuberculosis and occurred 2 months following a normal vaginal birth. We highlight the difficulties in the management of this uncommon condition in light of the relevant literature.

A 34-year-old woman who was previously healthy was presented at 2 months' postpartum with important right sciatica and low back pain without fever. Examination of the abdomen revealed tenderness in the right iliac fossa but obstetric/gynecologic and neurologic examinations were normal. The patient had an elevated C-reactive protein level and computed tomography (CT)-scan demonstrated a large psoas abscess on the right side without sacroiliac or spine abnormalities. Initial posterior lumbar percutaneous drainage was useful, but no pathogens were identified. The patient was discharged home with oral antibiotics therapy (amoxicillin/clavulanate and metronidazole). Four weeks later, the follow-up CT-scan showed a re-accumulation of the abscess cavity. Subsequently, the patient underwent a right anterolateral laparotomy with a retroperitoneal approach for abscess drainage. Again, no microorganisms were found. However, diagnosis of tuberculosis was established on histopathologic study. She was successfully treated with antituberculous drugs with a good outcome.

Most primary psoas abscesses present with a delay in diagnosis because of the rarity of this infectious disease, the lack of specific symptoms and signs, and its similarity to many differential diagnoses. When suspected, CT-scan and/or magnetic resonance imaging help in making an accurate diagnosis and facilitate percutaneous or open surgical drainage of the abscess. Correct and fast identification of the microorganisms in addition to appropriate usage of antibiotic regimen improves the outcome.