Hughes-Stovin Syndrome: A Case Report of a 24-Year-Old Male with Pulmonary Aneurysms and Deep Vein Thrombosis.

Background: Hughes-Stovin Syndrome (HSS) is a rare vasculitis characterized by pulmonary artery aneurysms (PAAs) and peripheral venous thrombosis. Anticoagulation, the standard treatment for venous thrombosis, is often contraindicated in HSS due to the risk of fatal pulmonary hemorrhage, especially since mortality rates of patients with a history of hemoptysis are reported at 50%-100% from PAA ruptures, yet treatment guidelines are limited due to the condition's rarity with fewer than 90 reported cases globally. This report highlights the complex management decisions required. Case Presentation: A 24-year-old man with a 3-month history of PAAs, left lower extremity deep vein thrombosis (DVT), and hemoptysis presented with worsening right lower extremity DVT after discontinuing apixaban due to the hemoptysis. He was initially evaluated for chest pain potentially signaling myocardial infarction, which was ruled out. Imaging confirmed extensive new bilateral lower extremity DVTs and a chronic infrarenal inferior vena cava (IVC) occlusion with collateralization. Importantly, the PAAs remained stable without imaging signs suggesting impending rupture. HSS was diagnosed based on the constellation of PAAs, recurrent DVT, and the patient's history of hemoptysis. Conclusion: Despite the inherent risks associated with anticoagulation in HSS, the decision was made to resume apixaban due to the patient's significant thrombotic burden and stable PAAs, alongside continued immunosuppression and close monitoring. This case underscores the necessity of individualized treatment in HSS, balancing thrombotic versus hemorrhagic risk in the absence of definitive guidelines. Further research is crucial to establish evidence-based strategies for managing anticoagulation in this complex patient population.