Gastrointestinal cancer

Gastrointestinal carcinoma, colon and rectal cancer is the second most common primary tumor, and it is also the most common visceral tumor that metastasizes to the skin. Most occur in the rectum, accounting for 11% to 19% of skin metastatic cancers in men and 1.3% to 9% in women. Colorectal cancer is usually found before skin metastases. Metastatic skin cancers from the gallbladder and bile ducts can be seen when the primary tumor is found, and can be as late as 40 years after the primary tumor is removed. Metastatic skin cancers from the stomach and pancreas usually occur before the primary tumor is found. The sites of skin metastasis from the stomach and intestines are usually the abdominal wall, perineum, and umbilicus.