An introduction to mucin-producing tumors of the pancreas: why they deserve more attention.

BACKGROUND/AIMS: Mucin-producing tumors of the pancreas are clinically characterized by dilatation of the major pancreatic duct due to pooled mucin, and by dilatation of the orifice of the duodenal papilla. The concept of mucin-producing tumors of the pancreas was proposed in 1982, but has undergone revision since then.

METHODOLOGY: The present paper reviews the history, classification, and description of mucin-producing tumors of the pancreas. Problems relating to this type of tumor are also discussed.

RESULTS

The clinical concept of mucin-producing tumors of the pancreas has affected studies of the pancreatic diseases in many areas. First, when recognition of pancreatic cancer with a relatively good prognosis commenced, this concept led to awareness of the necessity for a detailed examination of the pancreatic duct epitheliums in cases of suspected pancreatic carcinoma. Second, the concept made it easier to diagnose carcinoma in situ. Third, new classifications of cystic lesions of the pancreas were initiated. Fourth, a molecular biological view of the onset of pancreatic cancer was developed. Pathologically, this type of tumor is characterized by papillary growth of the epitheliums within the pancreatic duct, and it has been regarded as having a good prognosis. The term mucin-producing tumors of the pancreas now includes: intraductal papillary tumors which are non-invasive carcinomas or carcinoma in situ; duct-ectatic tumors, or mucinous cystic tumors; and, invasive carcinomas, derived from the former types.

CONCLUSIONS

The definition of "mucin-producing tumor of the pancreas" has been undergoing revision. In the past, it has referred to pancreatic tumors with a good prognosis. It is now time to consider a more detailed classification.