Beyond the Lungs: A Rare Case of Extrapulmonary Tuberculosis Presenting With Neck Vein Thrombosis and Seizure

<b>Introduction:</b> Tuberculosis (TB), caused by <i>Mycobacterium tuberculosis</i>, primarily affects the lungs but can involve virtually any organ system, manifesting as extrapulmonary TB. While TB-related hypercoagulability and venous thromboembolism are recognized, such presentations remain uncommon and diagnostically challenging, especially in the absence of classical symptoms. <b>Case Presentation:</b> We report the case of a 24-year-old immunocompetent female who initially presented with painless right-sided neck swelling. Imaging revealed an acute thrombus in the right internal jugular vein (IJV), with no clear underlying cause. Further evaluation showed enlarged necrotic mediastinal lymph nodes, raising suspicion for lymphoma. However, the patient later developed a seizure episode, and subsequent neuroimaging revealed multiple intracranial ring-enhancing lesions. Ultimately, mediastinoscopic lymph node biopsy confirmed necrotizing granulomatous inflammation, with a positive TB polymerase chain reaction (PCR), consistent with disseminated TB involving both vascular and central nervous systems. The patient was started on antitubercular therapy, anticoagulation, and adjunctive corticosteroids, with multidisciplinary follow-up arranged. <b>Discussion:</b> This case highlights TB-induced hypercoagulability as a potential cause of isolated venous thrombosis and underscores the diagnostic challenges when TB mimics malignancy. It also emphasizes the importance of considering TB in the differential diagnosis of unexplained thrombosis and intracranial lesions, even in the absence of pulmonary symptoms. <b>Conclusion:</b> Clinicians should maintain a high index of suspicion for extrapulmonary TB in atypical thrombotic events. Early tissue diagnosis and a multidisciplinary approach are key to effective management and favorable outcomes.