Mitral valve thrombus attached to the intact mitral valve associated with distal embolism

A 61-year-old man was referred for cardiac investigation because embolism w as suspected to be the cause of the sudden onset of severe pain in his righ t leg after a surgical procedure. The electrocardiogram revealed no atrial fibrillation. Transthoracic echocardiography demonstrated a tumor-like echo at the anterior mitral leaflet, and transesophageal echocardiography docum ented a mass 13 x 9 mm in size, attached by a stalk to the left atrial side of the anterior mitral leaflet. The other parts of the mitral valve appear ed to be intact. At emergency surgery, the mass was located in the center o f the left atrial side of the anterior mitral leaflet. It mimicked a myxoma and had a stall: arising from the anterior leaflet. After resection of the mitral valve mass, catheter thrombo-embolectomy was performed and several long pieces of fresh thrombus were removed. On histological examination, th e mass consisted of fresh thrombus tissue. No cellular component or myxoma tissue was documented. The distal embolus also consisted of fresh thrombus tissue. This is the first case of a thrombus of the intact mitral valve wit hout atrial fibrillation.