[A case of mucinous carcinoma of the skin]

We were consulted by an 81-year-old man who had been complaining of a slow-growing tumor on his abdomen for 20 years. Histologically, small islets of the tumor cells were floating in mucinous lake separated by fibrous septa, so we diagnosed this tumor as mucinous carcinoma of the skin (Mendoza). Electron-microscopically, nuclei of the tumor cells were slightly folded. There were a few secretory granules and many secretory vacuoles in cytoplasm, but no findings of decapitation secretion. Like some other authors' reports, our data suggest that this tumor has an eccrine gland origin. To our knowledge, this is the 12th case of mucinous carcinoma of the skin in the Japanese literature.