Cardiovascular pseudoneoplasms

Context: Primary cardiac tumors are rare and the great majority are benign neoplasms. Mass-forming reactive and pseudoneoplastic growths are less common, but recognizing and distinguishing these lesions from the neoplasms they resemble is critical to appropriate patient care. Objective: The general clinical, imaging, gross pathologic, and histologic features of 5 important pseudoneoplasms (inflammatory myofibroblastic tumor, hamartoma of mature cardiac myocytes, mesothelial/monocytic cardiac excrescences, calcified amorphous tumor, and lipomatous hypertrophy of the atrial septum) are discussed, with an emphasis on features differentiating them from other benign and malignant tumors. Data Sources: Pertinent citations of the literature and observations from the authors' experience are drawn upon. Conclusions: While lacking malignant potential, these lesions can be associated with considerable morbidity and occasional mortality. Their recognition is important in guiding patient management, providing both guidance for appropriate therapy and avoidance of inappropriately aggressive and toxic treatments.