Abnormally high CA199 is not necessarily a malignant tumor. CA199 is a relatively common clinical tumor marker, causing its elevation for a variety of reasons, may be pancreatitis, cholelithiasis, cirrhosis, diabetes and other diseases, but also may be pancreatic cancer, rectal cancer and other digestive tract malignant tumors. There is no way to determine the specific cause of the disease through a single CA199 index, just the higher the CA199 index the greater the chance of cancer, that is to say, CA199 abnormally high is not necessarily a malignant tumor. It is generally believed that CA199 level stays below 3 times of the normal range, mostly considered as a benign disease; if it is more than 10 times, then it is likely to be caused by cancer, and it is necessary to improve the abdominal CT, MRI, and biopsy of pathological tissues in a timely manner, so as to better define the cause of the disease and take targeted treatment. CA199 abnormalities need to follow the doctor’s instructions to improve the relevant examination, so as not to delay the condition.