Small calcifying fibrous pseudotumor of the heart confined to the epicardium.

A calcifying fibrous pseudotumor (CFPT) is a rare benign lesion that often presents in the upper and lower extremities of children and young adults. In the present report, we describe a case of a small CFPT arising from the epicardium (visceral pericardium) in a 32-year-old woman. The tumor presented as a 25-mm polypoid mass protruding into the pericardial cavity, without extending into the myocardium. A complete resection was performed, and the patient has not experienced any relapse for more than 2 years. On histological examination, the lesion contained densely hyalinized collagen with psammomatous and dystrophic calcifications, as well as patchy chronic inflammatory infiltrate. The localization in the epicardium with no involvement of the myocardium was confirmed by the elastic stain. Amyloid was negative by the Congo red stain. On immunohistochemical analysis, the lesional cells indicated diffuse positive staining for vimentin and factor XIIIa and focal positive staining for CD34, but did not indicate positive staining for other pertinent antigens such as cytokeratins, calretinin, desmin, α-smooth muscle actin, ALK, and estrogen and progesterone receptors as well as IgG4 in plasma cells. To our knowledge, only three cases of CFPT in the heart have been reported in the literature, all of which developed in young females as a large mass involving the epicardium; the lesion also extended to the parietal pericardium in two cases. Moreover, all cases presented with few symptoms, despite the large lesion. In the present case, the CFPT developed also in a young woman, but the lesion was much smaller than those previously published and was localized in the visceral serous membrane of the heart. The findings of this case suggest a potential preferable site of origin of CFPTs of the heart.