Background <p>Lemierre’s Syndrome (LS) is a rare but potentially fatal syndrome that usually starts with a throat and neck infection and leads to blood clots, septicemia, and thrombosis of the internal jugular vein. Fusobacterium necrophorum, an anaerobic bacterium is the most common cause. Classically, it is seen in healthy adolescents following pharyngitis, but recent cases show a wider clinical spectrum and atypical sources and thrombotic sites, which complicates the diagnosis of the syndrome.</p> Case description <p>We reported a 57-year-old woman with a history of pulmonary tuberculosis (TB) who visited the hospital with facial swelling, shortness of breath, fever, and abdominal distension. Imaging showed a large facial abscess, pleural effusion, right lower lobe consolidation, and ascites. Blood and abscess culture grew Fusobacterium necrophorum. Notably, thrombosis was seen in the left brachiocephalic and subclavian vein rather than the usual internal jugular vein. The source of infection was traced to a dental abscess. She was treated with surgical drainage and antibiotics, which resulted in her clinical improvement. The ascitic fluid profile raised concern for tuberculous peritonitis, given her history.</p> Conclusion <p>This case shows the atypical presentation of LS, originating from a dental source and involving the atypical site of thrombosis with possible concurrent tuberculosis. This case highlights the critical need for clinicians to maintain a high index of suspicion for LS, even in the absence of its classic features, to ensure timely diagnosis and intervention. Early recognition, prompt imaging, culture, and targeted treatment are key to managing such a complex presentation effectively.</p>