Case Report: When benign overgrowth turns fatal in CLOVES syndrome: underestimated perioperative risk.

CLOVES syndrome is driven by somatic activating PIK3CA mutations that constitutively activate the PI3K-AKT-mTOR pathway, resulting in segmental overgrowth and complex vascular malformations. Emerging evidence suggests these vascular lesions are biologically active and may pre-dispose to localized intravascular coagulation and thrombosis. We report a 21-year-old man with genetically confirmed CLOVES syndrome who developed concurrent consumptive coagulopathy and hypercoagulability. Post-operatively, he experienced both hemorrhagic and thromboembolic complications, culminating in fatal cardiac arrest. This case highlights a fragile perioperative hemostatic balance in CLOVES syndrome, underscoring the need for careful risk stratification and multidisciplinary management.