A Rare Case of Empyema Necessitans Due to Streptococcus Anginosus with Necrotizing Fasciitis and Retroperitoneal Abscesses.

BACKGROUND: Necrotizing fasciitis (NF) is a rapidly progressive soft-tissue infection associated with high mortality even when recognized early. Empyema necessitans (EN) is an uncommon complication of pleural empyema in which purulent material extends beyond the thoracic cavity into surrounding soft tissues. Although classically linked toand, EN due tois distinctly rare. In exceptional cases, extra thoracic spread of empyema can track along fascial planes and evolve into NF.

CASE REPORT: A 36-year-old previously healthy woman, recently treated for bilateral empyema, re-presented in severe respiratory distress and septic shock. She was found to have a foul-smelling open thigh wound, widespread soft-tissue involvement, and laboratory evidence of severe infection. Computed tomography (CT) imaging demonstrated bilateral multiloculated empyema with chest-wall extension consistent with EN, NF of the right thigh, multiple large retroperitoneal abscesses, and emphysematous cystitis (EC). She required intubation, vasopressor support, broad-spectrum antibiotics, and multiple surgical debridements. Pleural cultures grew. Retroperitoneal abscesses were managed conservatively, and multidisciplinary care led to steady clinical improvement. After approximately 5 weeks, her empyema had resolved, and her thigh wounds healed adequately, allowing discharge on oral antibiotics.

CONCLUSION: This case illustrates an exceptionally rare progression ofempyema to EN with concurrent NF and widespread retroperitoneal involvement. Early recognition of atypical dissemination, aggressive surgical management, and coordinated multidisciplinary care are essential for survival in such complex presentations.

LEARNING POINTS: , although a commensal organism, has strong abscess-forming potential and can cause disseminated, life-threatening infections even in immunocompetent adults.This case highlights the importance of optimal treatment of lung empyema. Partially treated lung empyema can lead to empyema necessitans, with pus tracking along fascial planes and causing multiple superficial and retroperitoneal abscesses.Early recognition, repeated surgical source control, and multidisciplinary collaboration are critical to survival in multifocal invasive infections.