title: Cardiac MICE--tumor or thrombus?
abstract: BACKGROUND
  Mesothelial/monocytic incidental cardiac excrescence (cardiac MICE) is a rare intracardiac lesion, which can cause severe disease and lead to misdiagnosis.
  
  
  METHODS
  A 66-year-old woman with floppy mitral valve and coronary atherosclerosis underwent diagnostic coronary angiography, mitral valve surgery and aortocoronary bypass. During surgery, a thrombus was detected inside the left atrium and sent for pathology analysis. The sample was routinely processed, stained with histochemical dyes and immunomarked for epithelial (keratin) and mesenchymal cells (vimentin), histiocytes (lysozyme) and endothelial cells (Factor VIII).
  
  
  RESULTS
  Histologically, the lesion contained mesothelial cells (keratin/vimentin coexpression), histiocytes (lysozyme/vimentin positive) and fibrin, leading to a diagnosis of MICE.
  
  
  CONCLUSIONS
  Cardiac MICE is a benign cardiac tumor-like lesion. It may be misdiagnosed as a thrombus or neoplasia, either primary or metastatic. Through embolization, it may cause myocardial or multiorgan infarctions, in some cases fatal. Developments in cardiothoracic surgery and interventional cardiology may increase its incidence; hence the importance of recognizing this entity.
authors.affiliation: Serviço de Anatomia Patológica, Hospital de Santa Cruz, Carnaxide. rhgouveia@mail.telepac.pt
authors.forename: Rosa Henriques
authors.initials: RH
authors.lastname: de Gouveia
authors.forename: Sância
authors.initials: S
authors.lastname: Ramos
authors.forename: Miguel Almeida
authors.initials: MA
authors.lastname: Ribeiro
authors.forename: Moradas
authors.initials: M
authors.lastname: Ferreira
authors.forename: Ana Paula
authors.initials: AP
authors.lastname: Martins
mesh_terms: D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006331:Heart Diseases / Q000473:pathology*; D006338:Heart Neoplasms / Q000473:pathology*; D006801:Humans; D013927:Thrombosis / Q000473:pathology*