A case of mesothelial/monocytic cardiac excrescence causing severe acute cardiopulmonary failure.
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.
Pham
Truc Thanh
TT
Department of Pathology, University of California, San Diego, CA 92103-8720, USA. trucpham@ucsd.edu
Antons
Kenneth
K
Shishido
Ralph
R
Mullvain
Jeffrey
J
Salem
Fakhri
F
Haghighi
Parviz
P
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*