Chondroid syringoma with tyrosine crystals: case report and review of the literature.

Chondroid syringoma (CS) is a relatively rare cutaneous mixed tumor arising from sweat glands. It usually presents in the head and neck area as an asymptomatic, slow-growing, firm, circumscribed, lobulated nodule within the dermis or subcutaneous fat. CSs share morphologic similarities with their salivary gland counterparts, pleomorphic adenomas (benign mixed tumors). Although the presence of tyrosine-rich crystalloids in mixed tumors of the salivary gland is well recognized, to our knowledge, this finding has not been previously described in mixed tumors of the skin. We report a case of tyrosine crystalline structures in a CS and review the pertinent literature.