Multimodal Imaging of Papillary Muscle-Origin Left Ventricular Myxoma.

Abstract

Background: Cardiac myxomas most commonly originate in the left atrium, whereas occurrences in the ventricles are rare, accounting for only 3% to 4% of cases. Their pseudoinvasive growth, which can mimic malignancy, poses significant diagnostic challenges.

Case summary: A 49-year-old asymptomatic man underwent transthoracic echocardiography, revealing a 27.5 × 16.5 mm moderately echogenic mass in the midlateral left ventricle, adjacent to the anterior papillary muscle. Further examination showed the mass with low-density margins merging with the chordae tendineae on computed tomography (54 HU), homogeneous T2 hyperintensity with delayed "cloud-like" enhancement on cardiac magnetic resonance imaging, and moderate metabolic activity (SUV_max = 7.8) on positron emission tomography/computed tomography. Histopathological examination confirmed the mass as a benign myxoma with pseudoinvasive entrapment of the papillary muscle. Subtotal resection was performed, successfully maintaining mitral valve integrity.

Discussion: This case demonstrates the value of integrated imaging techniques in differentiating pseudoinvasive cardiac myxomas from malignant tumors, thereby enhancing diagnostic approaches for ventricular masses.

Take-home messages: Multimodal imaging is crucial for diagnosing cardiac tumors located in atypical regions. Recognizing benign pseudoinvasive patterns is key to avoiding unnecessary radical surgery.