Case report of rare right intraventricular thrombus: a diagnostic and anticoagulation management challenge

Background Antiphospholipid syndrome (APS) is a rare autoimmune disorder characterized by an increased risk for both arterial and venous thrombosis. This case of a right intraventricular thrombus mimicking a cardiac tumor highlights the complexities of anticoagulation management in APS. Case Summary A right intraventricular mass was incidentally discovered in a 54-year-old woman undergoing assessment for an unexplained cerebral stroke. Imaging revealed a 27 × 15 mm pedunculated mass in the right ventricle without atrial fibrillation, intracardiac shunt lesion, or deep vein thrombosis. The patient was initially started on a direct oral anticoagulant (DOAC), but the intracardiac mass did not change in size, prompting a referral for further management. Due to the large size and high mobility of the mass, and the associated risk of pulmonary embolism, surgical resection of the mass was performed. Histopathologic examination revealed the mass to be an organized chronic thrombus. Postoperatively, the patient continued treatment with a DOAC but experienced recurrent cerebral strokes requiring 4 months’ rehabilitation, which delayed the definitive diagnosis of APS. Anticoagulation therapy was changed to therapeutic warfarin thereafter. Discussion Diagnosing a right intraventricular thrombus is particularly challenging if it is the first clinical venous thrombotic event associated with APS. This case emphasizes the importance of considering APS in patients presenting with unexplained arterial and venous thrombosis. Warfarin is preferred over DOACs unless the diagnosis of APS is ruled out, even if the thrombus is completely removed.