Psoas muscle abscess simulating acute appendicits: A case report

Psoas abscess is a rare clinical entity with vague symptomatology. We report a psoas abscess that simulated symptoms of acute appendicitis.

A twenty-five year old male presented pain irradiating to the right iliac fossa and lumbar region associated with thigh flexion. Laboratorial exams revealed leukocytosis with a neutrophil shift to the left. Abdominal Ultrasound showed significant intestinal distension and a small quantity of free fluid at the right iliac fossa. Laparotomy and an appendectomy were performed. During immediate post-operative, the patient evolved with worsening of the pain and the leukocytosis, therefore, we chose to maintain his antalgic posture. An abdominal Computerized Tomography scan with contrast was solicited, revealing an increase of the iliac and psoas muscles of the right side, and multiple bacterial focuses. A retroperitoneal access was performed and 300ml of purulent secretion was drained. Afterwards, we implanted a Penrose Drain. The patient had a good post-op evolution, being discharged 7days after the drainage.

The psoas muscle is a flexor of the thigh. Psoas abscess is an underdiagnosed condition, its main treatment is surgery associated with antibiotic therapy. CT scan seems to be the best choice of diagnostic image exam, although some authors prefer the nuclear magnetic resonance.

The psoas muscle abscess is uncommon and poorly characterized in its etiology, clinical associations, and its therapeutic approach. On the other hand, acute appendicitis is the most common abdominal emergency, with a 7% death rate, and surgery is its main treatment.