Incidental Mesothelial/Monocytic Cardiac Excrescenceand Literature Review

We present a case of the so-called mesothelial monocytic incidental cardiac excrescences (MICE) of the heart and a brief review of related literature. The patient was a 74- year- old woman. She had no history of previous cardiac instrumentation and underwent pericardial drainage and biopsy due to cardiac tamponade. A tissue sample was submitted as thrombus attached to the pericardium. Histologically، these lesions were composed of a mixture of plump histiocytoid cells، a papillary and strip rrangement of cuboidal cells، and various sized vacuoles and fibrin. The nests of cuboidal ells resembled cancer cells but showed features of mesothelial cells. mmunohistochemically، histiocytic cells were positive for CD68 but negative for ytokeratin. The cuboidal cells were positive for cytokeratin but negative for CD 68. These esions were probably reactive because of their heterogeneous components. The significance f MICE is its possibility of being misdiagnosed as metastatic carcinoma.