Although patients with the carcinoid syndrome may have a variety of manifestations which involve the skin, gastrointestinal carcinoids rarely metastasize to the skin or subcutaneous tissue. The literature is reviewed regarding this occurrence, and an additional case is presented. Four of the six patients described had a primary tumor in the small intestine. This is not unexpected since this area has the highest rate of metastasis of carcinoid tumors.
Norman JL, Cunningham PJ, Cleveland BR. Skin and Subcutaneous Metastases From Gastrointestinal Carcinoid Tumors. Arch Surg. 1971;103(6):767-769. doi:10.1001/archsurg.1971.01350120131027