cardiac myxoma
Pronunciation: mik-SO-ma
Most common primary cardiac tumor, typically arising from the atrial septum and composed of stellate cells in a myxoid matrix.
Full Definition
Cardiac myxoma represents the most common primary cardiac tumor in adults, typically presenting as a pedunculated mass arising from the atrial septum, most commonly the left atrium near the fossa ovalis. Histologically, myxomas are characterized by stellate or polygonal cells embedded in an abundant myxoid (mucopolysaccharide-rich) matrix, often with associated hemorrhage, hemosiderin deposition, and calcification. The tumor surface may show organization of thrombi, and the stalk typically shows vascular proliferation. While generally benign, myxomas can cause mechanical obstruction, systemic embolization, or constitutional symptoms. Grossly, they appear as smooth, lobulated, gelatinous masses that may be friable or calcified.
Usage
Usage note: Always specify anatomic location; distinguish from organized thrombus which lacks the characteristic histology.
In Context
- "The 4.5 cm cardiac myxoma was successfully excised along with a rim of normal atrial septum." — Cardiac surgery pathology
- "Microscopic examination confirmed cardiac myxoma with typical stellate cells in a myxoid background." — Tumor pathology report