Papillary fibroelastomas are the most common tumors of valvular origin, accounting for approximately 8% of primary cardiac tumors.^[1] They are most frequently associated with embolic phenomena due to their mobility.^[2,3] They are generally characterized by their small, pedunculated morphology and frond-like projections.^[3] Most PFEs are located on the aortic or mitral valves, with less frequent occurrences on non-valvular endocardial surfaces.^[2] The case presented here involves an unusual tumor attached near the orifice of the left atrial appendage and the anterior mitral leaflet but extending into the atrial cavity, a highly atypical site for PFEs, and underscores the need for a multidisciplinary approach in such rare presentations.^[4]

A 34-year-old female presented with a history of an acute ischemic stroke in the distribution of the left middle cerebral artery (MCA) in August 2024, managed successfully with intravenous thrombolysis. She reported persistent post-stroke deficits, including right-sided hemiparesis and sensorimotor aphasia. Comprehensive genetic testing for thrombophilia revealed no significant predisposition for thromboembolic events. The patient’s medical history was otherwise unremarkable.

The patient underwent a median sternotomy due to the very small femoral arteries and high risk from peripheral perfusion. Normothermic cardiopulmonary bypass was established with aortic and bicaval cannulation. Cold crystalloid cardioplegia (VitaOrgaSol) was administered to achieve myocardial protection. Upon performing a left atriotomy, a mobile, pedunculated, frond-like tumor was identified, originating from the left atrial wall near the anterior mitral leaflet (Fig. 2A). The mass was meticulously excised en bloc using a Beaver blade to preserve adjacent structures and was subsequently sent for histopathological analysis (Fig. 2B). To minimize the risk of recurrence, cryoablation was applied to the tumor’s attachment site (Fig. 2C).

The postoperative recovery was uneventful. The patient was extubated without complications and remained hemodynamically stable. Rehabilitation was initiated on postoperative day 2. Follow-up imaging demonstrated no residual mass or recurrence. The patient was discharged on postoperative day 5 with acetylsalicylic acid 100 mg once daily and recommendations for neurological and cardiac follow-up.

Histological examination confirmed the diagnosis of papillary fibroelastoma, characterized by a central avascular core of dense collagen and elastic fibers with peripheral endothelial lining.^[5,6] No evidence of malignancy or myxoid stroma was observed, ruling out the initial diagnosis of myxoma.

Papillary fibroelastomas, though benign, are clinically significant due to their embolic potential, particularly when located in the left atrium.^[7–9] This case highlights a rare presentation of PFE atypically located near the orifice of the left atrial appendage and the anterior mitral leaflet, extending into the left atrium.^[4] The differential diagnosis included myxoma, thrombus, and vegetation, but definitive histology clarified the diagnosis.^[5,10-12] While PFEs are predominantly valvular, cases involving non-valvular surfaces, particularly near the mitral annulus, are exceedingly rare.‌^[2] Tumors near valves are more prone to embolization due to mobility and proximity to high-velocity blood flow.^[2,3,8] Myxomas are more commonly associated with atrial locations and may overlap in imaging characteristics.^[1,4] However, histological analysis confirmed the tumor’s identity as a fibroelastoma.^[10] Surgical excision remains the gold standard for management, particularly for symptomatic or mobile lesions.^[13–16] Cryoablation of the tumor base further reduces recurrence risk in cases of atypical attachment.^[14]

This case represents a rare instance of a papillary fibroelastoma located near the orifice of the left appendage and the mitral valve but not originating directly from it. Accurate imaging, surgical expertise, and histological confirmation were imperative for diagnosis and management. Such cases highlight the variability in PFE presentation and the importance of individualized treatment planning to optimize outcomes. Early surgical intervention was essential in mitigating the risk of further embolic events and ensuring the patient’s recovery.

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The authors have declared that no competing interests exist.