Plasma cell granuloma of the heart.

A case of plasma cell granuloma arising in the free ventricular wall and involving the coronary arteries of a 10-month-old female infant is presented. Morphologic characteristics were comparable with those of plasma cell granulomas arising elsewhere. The histologic, immunohistochemical, and ultrastructural observations, and in particular the quiescent clinical course of the disease and its control with anti-inflammatory medication, favor a nonneoplastic nature of the lesion. This report documents the presence of an intracardiac plasma cell granuloma for the second time in the medical literature.