Cardiac MICE--tumor or thrombus?
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.
de Gouveia
Rosa Henriques
RH
Serviço de Anatomia Patológica, Hospital de Santa Cruz, Carnaxide. rhgouveia@mail.telepac.pt
Ramos
Sância
S
Ribeiro
Miguel Almeida
MA
Ferreira
Moradas
M
Martins
Ana Paula
AP
D000368:Aged; D003937:Diagnosis, Differential; D005260:Female; D006331:Heart Diseases / Q000473:pathology*; D006338:Heart Neoplasms / Q000473:pathology*; D006801:Humans; D013927:Thrombosis / Q000473:pathology*