Image Description
Clinical Features: Lipomatous hypertrophy of atrial septum (LHAS) can produce a mass-like lesion bulging into the right atrial cavity, causing superior vena cava obstruction and clinically mimic right atrial myxoma. The fat deposits may extend into the AV node and produce heart block, arrhythmias (atrial and supraventricular tachycardias) or even sudden death in rare instances. When diagnosed antemortem, it is usually left alone unless it is causing arrhythmias. The image shows trichrome stain highlighting entrapped cardiac myocytes within LHAS.
Image courtesy of: Dr. Ibrahim Zardawi; used with permission.
About the Disease
Primary cardiac tumors are extremely uncommon. Secondary tumors (metastases to heart) are 20-50 times more common than primary cardiac tumors and yet still relatively rare. Of primary cardiac tumors, almost 75% are benign and the remaining 25% are malignant.Benign Primary Cardiac Tumors: Myxoma (50-70% of cases), rhabdomyoma, lipoma and lipomatous hypertrophy of interatrial septum, papillary fibroelastoma, and fibroma. Angiomas and teratomas are found mainly in children. Malignant Primary Cardiac Tumors: Mostly sarcomas, including angiosarcoma (30%), rhabdomyosarcoma (20%), leiomyosarcoma, liposarcoma, osteosarcoma, fibrosarcoma, and undifferentiated pleomorphic sarcoma. Other tumors include mesothelioma and lymphoma.Secondary cardiac tumors are far more frequent than primary cardiac tumors. The most common primary sites include melanoma, lung, breast, kidney, and lymphomas. Pericardium is usually affected, resulting in pericardial effusion.Cardiac tumors may be asymptomatic and found incidentally or present with obstructive, embolic, arrhythmic or systemic symptoms, depending upon the size and location of the mass. References: 1. Miller, D. V. & Revelo M. P. (2023). Diagnostic Pathology - Cardiovascular. 3rd Edition, Elsevier.2. Sheppard, M. N. (2022). Practical Cardiovascular Pathology 3rd Edition, CRC Press.3. Maximilian B. & Butany J. (2022). Cardiovascular Pathology 5th Edition, Academic Press.