Immunohistochemical characterization of chondroid syringomas.

This study was initiated because the histogenesis of chondroid syringomas (CSs), especially the role of the myoepithelial cells, is still controversial. Twelve cases of CS were analyzed by immunohistochemical methods with a broad panel of routinely used antibodies. The epithelial elements were classified as tubuloglandular components, stromal cells, and solid nests. The authors' results indicated the following: (1) The inner cell layers of tubuloglandular components have distinct epithelial features with cytokeratin (CK), carcinoembryonic antigen (CEA), and epithelial membrane antigen (EMA) positivity. (2) The outer cell layers had negative results for muscle-specific actin (MSA), desmin, CEA, EMA, and CK (if antibody AE1/3 was used) and had positive results for vimentin, S-100 protein, neuron-specific enolase (NSE), and in three cases for glial fibrillary acidic protein (GFAP). (3) The stromal cells and, to a lesser extent, the solid nests expressed immunophenotypes similar to those of the outer cell layers. These data suggest that the stromal components may derive from the outer cells of the tubuloglandular elements but derive from the outer cells of the tubuloglandular elements but do not confirm their exclusive myoepithelial origin.