Image Description
Microscopic Features: Some myxomas (especially right-sided tumors) show calcification and cartilaginous or osseous metaplasia (shown here). Other rare findings include extramedullary hematopoiesis, thymic remnants, and intestinal-type mucinous glands arising from foregut remnants (glandular myxomas; 2% of cases).
Cytologic atypia, increased cellularity, any mitotic activity, and necrosis are generally absent in cardiac myxomas. Presence of any of these features is highly suggestive of a malignant diagnosis such as myxosarcoma. Multiple sections must be examined to avoid missing a low-grade sarcoma.
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.