Supplementary Material for: Case Report: Sorafenib-induced Capillary Leak Syndrome

Capillary leak syndrome is a rare life-threatening disorder of acute endothelial hyperpermeability. It consists of initial fluid extravasation resulting in hypotension, hypoalbuminemia and hemoconcentration, followed by noncardiogenic pulmonary edema from rapid fluid remobilization into intravascular compartment. Drug-induced etiology is an important diagnostic consideration in cancer patients, particularly with use of antimetabolites, immunostimulants and monoclonal antibodies. Sorafenib-mediated capillary leak syndrome has never been reported. Here, we present the case of a 29-year-old female patient with a desmoid tumor of the thigh, who was admitted for acute hypoxic respiratory failure after recent initiation of sorafenib. She was found to have extensive pulmonary edema, bilateral pleural effusions, and hemoconcentration, all of which stabilized on supportive care with non-invasive mechanical ventilation and intravenous diuresis. Her infectious and cardiac work-up were negative. Given the temporal relationship between sorafenib use and symptom onset as well as a lack of an alternative etiology of her findings, patient was deemed to have sorafenib-induced acute capillary leak syndrome. Importantly, she did not become hypotensive prior to or during this hospitalization. To our knowledge, we reported for the first time an atypical presentation of acute capillary leak syndrome due to sorafenib use without hemodynamic instability.