Non-traumatic acute mediastinitis secondary to acute phlegmonous esophagitis: a rare case report.

Acute mediastinitis secondary to acute phlegmonous esophagitis (APE) is an exceptionally rare, life-threatening condition with high morbidity. We report a 75-year-old diabetic female with recent severe pneumonia who presented with pleuritic chest pain, dyspnea, and elevated inflammatory markers. Computed tomography pulmonary angiography excluded embolism but revealed diffuse long-segment esophageal wall thickening with mediastinal fat stranding, aortic encasement, and pleural effusion, features consistent with APE and secondary non-traumatic mediastinitis without overt perforation. Given clinical stability, endoscopy was deferred to avoid disrupting a possible contained micro-perforation. The patient was successfully managed with 14 days of empiric broad-spectrum intravenous antibiotics (vancomycin, cefepime, metronidazole), achieving complete clinical and radiographic resolution. This case underscores that in hemodynamically stable patients without free perforation or large abscess, conservative antimicrobial therapy can be definitive. It also highlights the importance of considering APE in non-surgical patients presenting with acute chest pain.