title: A case of mesothelial/monocytic cardiac excrescence causing severe acute cardiopulmonary failure.
abstract: Mesothelial/monocytic incidental cardiac excrescence (MICE) is a benign lesion composed of a haphazard mixture of mesothelial cells, histiocytes, and fibrin, often found incidentally during cardiac valve replacement. Its pathogenesis is controversial with some authors favoring an artifactually produced amalgam while others espoused a reactive phenomenon. Clinically, this entity is important because of potential misdiagnoses as malignancies. We report a case in a 65-year-old man with severe acute aortic regurgitation. A 2.0-cm mobile aortic valve vegetation was documented by transesophageal echocardiography prior to any cardiac instrumentation. At surgery, the lesion was immediately visualized together with free-floating vegetation in the left ventricular outflow tract. Routine and immunohistochemical examination showed a nodule composed of predominantly histiocytes and mesothelial cells, together with fibrin and scattered neutrophils. To our knowledge, this is the first reported case of a mesothelial/monocytic cardiac excrescence causing acute cardiopulmonary failure. The literature on MICE is reviewed with discussion of its etiology.
authors.affiliation: Department of Pathology, University of California, San Diego, CA 92103-8720, USA. trucpham@ucsd.edu
authors.forename: Truc Thanh
authors.initials: TT
authors.lastname: Pham
authors.forename: Kenneth
authors.initials: K
authors.lastname: Antons
authors.forename: Ralph
authors.initials: R
authors.lastname: Shishido
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Mullvain
authors.forename: Fakhri
authors.initials: F
authors.lastname: Salem
authors.forename: Parviz
authors.initials: P
authors.lastname: Haghighi
mesh_terms: D000208:Acute Disease; D000368:Aged; D001021:Aortic Valve / Q000000981:diagnostic imaging / Q000473:pathology; D001022:Aortic Valve Insufficiency / Q000150:complications / Q000473:pathology*; D017548:Echocardiography, Transesophageal; D004848:Epithelium / Q000473:pathology; D006333:Heart Failure / Q000150:complications / Q000473:pathology*; D006644:Histiocytes / Q000473:pathology*; D006801:Humans; D008297:Male; D009206:Myocardium / Q000473:pathology*; D011654:Pulmonary Edema / Q000150:complications / Q000473:pathology*