Mucinous carcinoma of the skin.

Primary mucinous carcinoma of the skin is a rare adnexal neoplasm with sweat gland differentiation. We describe a case of primary mucinous carcinoma of the skin and characterize its clinical and histologic features. Mucinous carcinoma can occur in noncutaneous visceral sites and may metastasize to the skin. Thus it is important to exclude the possibility of a noncutaneous visceral primary tumor before diagnosing primary mucinous carcinoma of the skin.