A case report of a giant left atrial myxoma traversing a patent foramen ovale as a biatrial myxoma

Introduction Cardiac myxomas are the most common primary cardiac tumors, typically located in the left atrium. A rare and clinically significant variant is the biatrial myxoma, which most commonly extends from the left to the right atrium by traversing a patent foramen ovale (PFO). These tumors can present with a triad of embolic phenomena, obstructive symptoms, and constitutional symptoms, posing a high risk of life-threatening complications. Background Cardiac myxomas, though rare benign tumors with an incidence of approximately 0.0017%, represent the most common primary cardiac neoplasm. Biatrial involvement is exceptionally uncommon. This report presents a case of a giant left atrial myxoma traversing a patent foramen ovale (PFO), thereby simulating a true biatrial tumor. Conclusion This case highlights that a left atrial myxoma traversing a patent foramen ovale can mimic a biatrial tumor on imaging, underscoring the critical need for multimodal assessment to guide complete surgical excision and prevent catastrophic embolic complications. However, the generalizability of this finding is limited by the single-case nature of this report. Ultimately, despite its benign histology, timely and precise resection remains paramount, as it offers an excellent prognosis in most cases and underscores the importance of considering cardiac tumors in the differential diagnosis of unexplained embolic events.