Hyaline-cell rich chondroid syringoma. A tumor mimicking malignancy

We report three cases of chondroid syringoma composed almost entirely of hyaline cells and occurring in the soft tissues. These lesions were confused with a variety of malignant neoplasms, including malignant melanoma, myxoid chondrosarcoma, and alveolar soft part sarcoma. The tumors occurred in two men and one woman aged 37, 75, and 71 years, respectively, and involved the heel, great toe, and face. All cases arose in the subcutaneous tissue or fascial layer and ranged in size from 0.8 to 2.0 cm. The neoplasms were composed of plasmacytoid hyaline cells with variable amounts of myxoid stroma. Two of the chondroid syringomas contained rare duct structures. One contained cartilage lobules but no ducts. All were well circumscribed. Immunohistochemistry showed positive staining for keratin, S-100, and vimentin in all cases. Muscle markers, including desmin, smooth-muscle actin, and muscle-specific actin, were negative. Follow-up has showed no evidence of recurrence or metastasis.