Calcified amorphous tumor of the heart with mitral annular calcification: a case report

Calcified amorphous tumor of the heart is a rare, non-neoplastic cardiac mass characterized by nodular calcium in the background of amorphous degenerating fibrinous material. Clinical diagnosis of calcified amorphous tumor can be difficult, and current single imaging techniques do not specifically differentiate calcified amorphous tumor from other cardiac tumors such as calcified atrial myxoma, calcified thrombi, or vegetation. Complete surgical resection is the treatment of choice for both symptom improvement and prevention of embolization, as well as for pathological diagnosis.

A 70-year-old Asian man with end-stage renal disease complained of chest discomfort during exercise. He had no history of thromboembolism or endocarditis. A transthoracic echocardiogram revealed mitral annular calcification as well as a highly mobile mass (8 × 6 mm) attached to the ventricular side of the posterior mitral valve leaflet. As the mass was highly mobile, suggesting a high risk of embolization, he underwent surgical resection. A histopathological examination revealed multiple nodular amorphous calcifications, along with fibrous connective tissue. There were no identifiable myxoma or malignancy cells. Consequently, the diagnosis of calcified amorphous tumor was confirmed.

In the present case, a calcified amorphous tumor arose from mitral annular calcification. A characteristic of mitral annular calcification-related calcified amorphous tumor is its highly mobile nature, with a high risk of stroke or other systemic embolism. Therefore, surgical therapy should be considered for treatment of calcified amorphous tumors.