Rapid daily expansion of highly mobile intracardiac calcified tissue: a case report

A calcified amorphous tumour (CAT) is a non-neoplastic mass lesion arising within the cardiac chamber. CATs are rare but are a common cause of organ embolism. In the present study, we experienced a case of an intracardiac mass with calcification that, in contrast to a typical CAT, suddenly appeared and rapidly expanded without an inflammatory response based on pathological findings.

A 58-year-old Japanese man undergoing peritoneal haemodialysis had a high-echoic mobile mass (15 × 6 mm), which was not visible on the transthoracic echocardiography (TTE) approximately a month earlier, in the left ventricular outflow tract noted on TTE performed during a close examination for fever. Although multiple blood cultures were negative, ampicillin/sulbactam and ceftriaxone were initially administered because of suspected blood culture-negative endocarditis. The mass rapidly enlarged (22 × 5 mm) over the following days. A CAT was suspected and resected based on imaging findings with calcification; however, the pathological findings did not indicate inflammation and fibrin that are typically found in CATs. Echocardiography performed 12 months after the resection showed no recurrence.

This intracardiac calcified tissue had several similar features to a CAT. However, the initial presentation, enlargement rate, and pathological features of the tissue differed from that of a typical CAT. Although it is unknown whether this mass is a subtype of CAT, when an intracardiac calcified tissue is detected using an imaging test, careful follow-up or early surgical resection should be considered given the possibility of rapid tissue enlargement and embolism caused by the mass.