Fourteen cases of primary mucinous carcinoma of the sweat glands occurred. Tumors of this type in the skin are frequently misdiagnosed as metastatic carcinoma. Histochemically, the mucin is of the sialomucin type. The tumor is commonly a round, elevated, reddish, and sometimes ulcerated mass, usually located on the face, head, or trunk. These masses tend to recur, but metastasis is infrequent.
Mendoza S, Helwig EB. Mucinous (Adenocystic) Carcinoma of the Skin. Arch Dermatol. 1971;103(1):68-78. doi:10.1001/archderm.1971.04000130070011