INTRADUCTAL PAPILLARY TUMORS AND MUCINOUS CYSTIC TUMORS OF THE PANCREAS - CLINICOPATHOLOGICAL STUDY OF 38 CASES

Clinicopathological features of 28 patients with intraductal papillary tumor (IDPT) and 10 patients with mucinous cystic tumor (MCT) of the pancreas were studied. Both IDPT and MCT showed papillary projections of the epithelium with abundant mucus secretion in the ectatic ducts o r cystic spaces. The patients with IDPT comprised 19 men and 9 women w ith a mean age of 64.9 years. Three fourths of the IDPTs were located in the pancreatic head, and the mean tumor size was 3.5 cm. Local recu rrence was observed in one patient, but none died of IDPT. In contrast , all patients with MCT were women, with a mean age of 49.4 years. Non e of the MCTs arose in the head, and the mean tumor size was 7.1 cm. O ne patient died of MCT, but all of the others survived without recurre nce. Eight IDPTs and three MCTs showed invasion into the surrounding p ancreatic tissue. Muconodular infiltration was mainly observed in five IDPTs and one MCTs and tubular infiltration in three IDPTs and two MC Ts. A characteristic histological finding associated with the muconodu lar infiltration in IDPT was subepithelial ''mucin droplets'' that app eared to represent a change in polarity of mucus secretion. The format ion of such subepithelial ''mucin droplets'' may be the initial step o f muconodular infiltration in IDPT. Muconodular infiltration in IDPT a ppears different morphologically and biologically from the mucinous ca rcinoma subtype of conventional invasive ductal carcinoma. Copyright ( C) 1997 by W.B. Saunders Company.