MALIGNANT CHONDROID SYRINGOMA - IMMUNOHISTOPATHOLOGY

Malignant chondroid syringoma, also called malignant mixed tumor of th e skin, is a rare variant of a malignant tumor derived from sweat glan d cells. Histologically the tumor is composed of an epithelial and a m esenchymal component. The epithelial structures show glandular differe ntiation and carcinomatous features. They are embedded in a mucinous s troma with spindle mesenchymal cells and areas of chondroid differenti ation. The epithelial cells express cytokeratins. The luminal epitheli al cells show binding to the lectin Ulex europaeus; intraluminal cells are carcinoembryonic antigen positive. The stromal cells are cytokera tin negative and sporadically positive for vimentin. Chondroid areas a re S-100 protein and vimentin positive. No labeling for actin is seen.