Azygos vein thrombosis and vertebral osteomyelitis: A rare variant of Lemierre syndrome.

Lemierre syndrome, traditionally defined as septic thrombophlebitis of the internal jugular vein following an oropharyngeal infection, is most commonly caused by Fusobacterium necrophorum. We report an unusual variant of this syndrome in a 29-year-old male who presented with F. necrophorum bacteremia following tonsillar infection, complicated by vertebral osteomyelitis of the T10 vertebral body, azygos vein thrombosis, and septic pulmonary emboli (infected emboli that lodge in the lungs). The patient developed severe thrombocytopenia, consistent with the thrombogenic properties of F. necrophorum. Initial treatment with intravenous cefepime and metronidazole was administered, followed by ampicillin-sulbactam, and subsequently switched to oral clindamycin due to a drug eruption. The patient completed a 12-month course of antibiotics with full clinical recovery and no evidence of relapse at 20-month follow-up after treatment completion. While the classical definition of Lemierre syndrome focuses on internal jugular vein involvement, our case supports a broader conceptualization that encompasses septic thrombophlebitis at various vascular sites. This atypical presentation highlights the importance of thorough radiological evaluation in patients with persistent oropharyngeal symptoms and unexpected systemic manifestations, even when the classic internal jugular vein thrombosis is absent. The unique combination of thoracic vertebral osteomyelitis and azygos vein thrombosis represents an extremely rare manifestation with significant implications for diagnosis and management.