[Rare association of a mixed tumor of the skin with a carcinoma of low grade malignancy. Clinical case].

Chondroid syringoma, previously called mixed tumor of the skin is a fairly uncommon type of sweat gland tumor, most often diagnosed in the sixth and seventh decade of life. It presents as a well encapsulated dermal or subcutaneous module and it is most frequently found in the skin of the head and neck. The neoplasm is asymptomatic and is featured by a slow rate of growth. At histopathological examination, the tumor consists of an epithelial component, with glandular or ductal differentiation, either eccrine or apocrine, and a stromal component with myxoid or chondroid elements. Surgical removal is the treatment of choice and recurrence may occur. Malignant chondroid syringoma has been reported rarely, most frequently arising in previously benign lesions. They behave as lethal tumors and often metastasize to the regional lymph nodes and lung. We report a most unusual case of a mixed tumor of the skin localized in the sacral area associated with a peripheral low grade malignant component of the adenocystic type. Association of these two types of sweat gland tumors has never been previously described, to our knowledge.