A case of primary non-tuberculous psoas abscess is reported and the literature reviewed. The aetiology of psoas abscess is varied and there is a worldwide variation in the aetiology. Primary psoas abscess is due to Staphylococcal infection. The pathophysiology, clinical features, diagnosis and treatment are discussed with emphasis on the changing pattern in the aetiology and diagnosis.
Staphylococcus Aureus is a Gram-positive cocci bacteria which had been found to be the causative organism in over 88% of patients with primary iliopsoas abscess. We report the case of a 53-year-old diabetic woman with end-stage renal failure diagnosed with left iliopsoas abscess with a catheter-related infection. Computed tomogram (CT) of abdomen and pelvis revealed hypodense lesions of left psoas, iliacus and quadratus lumborum suggestive of psoas abscesses. In addition, osteomyelitis changes at left sacroiliac and hip joint were seen. At surgery, she was found to have abscess at the posterior psoas muscle where she underwent open surgery drainage and percutaneous drain was inserted. A high index of suspicion of iliopsoas abscess should be maintained among haemodialysis patients presenting with intradialytic pelvic and hip pain and treated with optimal antibiotics therapy with appropriate surgical intervention.
The presentation and management of psoas abscess was studied prospectively in 5 patients and retrospectively in 4. 3 patients had bilateral abscesses. All patients had back pain and a mass in loin or iliac fossa. 7 patients had no hip findings. One patient had a perinephric abscess and another had radiological features of tuberculosis of the spine. In the other seven no cause for the abscess could be identified. Ultrasonography demonstrated the abscess in all patients; CT scanning done in 5 patients was confirmatory. Drainage was done by an extraperitoneal route. Biopsy of the abscess wall in 2 patients demonstrated tuberculosis. They, the patient with TB spine and 3 others put empirically on anti-tuberculosis chemotherapy responded well. The perinephric abscess grew Pseudomonas sensitive to gentamycin, but she and two other patients died due to multiorgan failure.
A 60-year-old Chinese lady presented with a left flank mass and weight loss. Plain films showed a sclerotic L1 vertebral body, osteopenic L2 and L3 vertebral bodies and loss of left psoas outline. However initially unrevealed history of previous carcinoma of the cervix caused confusion as to the aetiology of a sclerotic vertebral body associated with an left flank collection. Psoas abscess with adjacent bony osteomyelitis was initially suspected. The left flank mass turned out to be an infected necrotic large metastatic lymph node compressing the lower pole of the left kidney. The sclerotic and osteopenic vertebral bodies represented an unusual presentation of bony cervical carcinoma metastases.