Lemierre's Syndrome With External Jugular Vein Thrombosis Following Submandibular Sialadenitis: A Life-Threatening Complication.

BACKGROUND: Lemierre's syndrome is a rare but potentially life-threatening condition traditionally characterized by bacteremia, septic thrombophlebitis of the internal jugular vein, and metastatic septic emboli following pharyngotonsillitis. We report an atypical presentation originating from submandibular sialadenitis and complicated by external jugular vein thrombophlebitis. CASE PRESENTATION: A 26-year-old man presented with high-grade fever, sore throat, and right submandibular swelling persisting for 7 days. Contrast-enhanced CT revealed right submandibular sialadenitis, thrombosis of the right external jugular vein without abscess formation, and bilateral cavitary pulmonary lesions consistent with septic emboli. Blood cultures identified Fusobacterium necrophorum as the causative pathogen. The patient was managed in the intensive care unit with vasopressor support, high-flow nasal oxygen, weight-based therapeutic anticoagulation (enoxaparin), and targeted intravenous antibiotics. Complete clinical and radiological recovery, including venous recanalization, was achieved without surgical intervention. CONCLUSION: Clinicians must maintain a high index of suspicion for Lemierre's syndrome even when thrombosis involves noninternal jugular neck veins or when the primary infectious focus is nonpharyngeal. Prompt multidisciplinary management is key to favorable outcomes.