Mesothelial/monocytic incidental cardiac excrescences (MICE): report of a case and review of literature with focus on pathogenesis.

Mesothelial/monocytic incidental cardiac excrescence (MICE) is a benign lesion composed of histiocytes and mesothelial cells, usually found during cardiac surgery. To date, no more than 50 cases are reported in literature, and pathogenesis is still unclear even if different theories have been proposed. Here we report a case of MICE encountered during aortic valve replacement with typical histological features and extensive immunohistochemical investigation. To date, little information is available about the pathogenesis of MICE. We review the current literature focusing on the role of adhesion molecules such as CD31.