Atrial Myxoma

Figure A. H&E x4

Figure B. H&E x10

Figure C. H&E x20

Figure D. H&E x40

Figure E. Gross appearance

Collaboration: Joseph Cleveland, MD

Figure F. H&E x40

Figure G. H&E x40



Clinical History: 59 years old female presented with dyspnea with exercise. Her chest x-ray showed possible left atrial appendage enlargement. Echocardiogram was consistent with a left atrial myxoma.

Histology: H&E staining (Figures A, B, C & D) shows numerous fusiform, rounded and stellate lipidic cells in a background of abundant myxoid matrix (mucopolysacarides) infiltrated by scattered inflammatory cells. The myxoma cells have eosinophilic cytoplasm with large vacuoles and round to oval nuclei, with some cells arranged in layers to form vasoformative rings (Figure C, arrow). Scattered hemosiderin laden macrophages are also present.

Figure E is another case showing the gross appearance of these tumors with a multilobulated smooth surface, light tan and light yellow translucent parenchyma with patchy hemorrhage. These tumors are loosely embedded in the myocardial parenchyma and are easily enucleated during the surgical procedure. Figures F and G show the microscopic features of the gross tumor in Figure F.

(Last Edition: May 22, 2018 )