Cardiac myxoma is the most common benign tumor of the heart in adults. Their most common location is on the endocardium of the left side of the atrial septum, near the fossa ovalis. Most commonly they appear in an isolated case, less commonly in familial form or as part of the Carney complex.
This gross picture of an atrial l myxoma shows a smooth contour and glistening variegated cut surface with multiple cysts, and pale and hemorrhagic areas. The mass was attached to the atrial septum by a narrow pedicle indicated by the asterisk. Microscopically this tumor has a rich myxoid matrix.