Concomitant lipomatous hypertrophy and left atrial mass: Distinguishing benign from malignant.

Masses in and near the interatrial septum may be either benign or malignant. The most common mass near the interatrial septum is lipomatous atrial septal hypertrophy (LASH). LASH can be present in patients with intracardiac malignancies, myxomas, lipomas, or other cardiac masses. It is important to recognize the transesophageal echocardiography (TEE) characteristics of these pathologies to arrive at an accurate diagnosis with an appropriate plan for intraoperative resection. At the authors' institution, patients have been referred for surgery due to a finding of significant LASH masquerading as a left atrial myxoma. In challenging cases, TEE offers a thorough evaluation of the interatrial septum to delineate between multiple intracardiac masses.