CD56 (NCAM) expression in pancreatic carcinoma and the surrounding pancreatic tissue.

Expression of CD56, also known as the neural cell adhesion molecule (NCAM), in the pancreatic ducts of chronic pancreatitis is considered to represent a regenerative process of the pancreatic duct system. CD56 expression was analyzed in 25 tissue samples of invasive ductal carcinoma without mixed ductal-endocrine carcinoma of the pancreas, and in the surrounding non-cancerous pancreatic tissue. CD56 expression was detected in intercalated ducts (ICDs) of lobules in the pancreatic parenchyma showing chronic inflammation close to the carcinoma, but not in the carcinoma itself, in all cases. CD56 showed strong, diffuse expression in the areas with severe inflammation, but expression was weak in ICDs where the inflammation was mild. We suggested that CD56 expression is degenerative process in pancreatic tissue with chronic inflammation, and that examination of CD56 expression may be helpful in the differentiation of atypical degenerative ducts from cancerous ducts.