carcinoma /kär′sinō″mə/ [Gk, karkinos + oma, tumor] , a malignant epithelial neoplasm that tends to invade surrounding tissue and to metastasize to distant regions of the body. Carcinomas develop most frequently in the skin, large intestine, lungs, stomach, prostate, cervix, or breast. The tumor is firm, irregular, and nodular, with a well-defined border. Microscopically, the cells are characterized by abnormal size and shape, disproportionately large nuclei, and clumps of nuclear chromatin. −carcinomatous, adj.
