Rapid pulmonary fistulization complicating a psoas abscess with intraoperative hypoxemia: a rare case report

Psoas abscess is a relatively uncommon condition that can present with vague clinical features. Patients with this condition often present in different ways to different specialties leading to delays in diagnosis and management. The authors present a 47-year-old woman with complaint of vague abdominal pain, fever, and raised inflammatory markers who underwent CT examination. On CT, a collection was noted in the right iliac fossa that extended along the right retroperitoneum through the retrocrural space in the right lung base communicating with a cavitary pulmonary lesion with air-fluid level. The psoas abscess was drained. Our case presents a number of rare and intriguing features. Notably, the patient, who was immunocompetent, experienced a primary Staphylococcus infection that swiftly progressed to a sizable pulmonary abscess, a phenomenon uncommon in such hosts. The rarity further extends to the source of infection, originating abdominally but culminating in thoracic complications through contiguous spread from a retroperitoneal site. Despite the potential severity, the patient's outcome was remarkably positive. This case underscores the potential rapidity of pulmonary involvement in psoas abscesses, emphasizing the need for heightened awareness and consideration of respiratory signs during preoperative assessments.