Morphological patterns of primary nonendocrine human pancreas carcinoma

The study of histological sections of 406 cases of nonendocrine pancreas carcinoma at Memorial Hospital indicated that morphological patterns of pancreas carcinoma could be delineated as follows: duct cell adenocarcinoma (76%), giant-cell carcinoma (5%), microadenocarcinoma (4%), adenosquamous cancinoma (4%), mucinous adenocarcinoma (2%), anaplastic carcinoma (2%), cystadenocarcinoma (1%), acinar cell carcinoma (1%), carcinoma in childhood (under 1%), unclassified (7%). In 195 cases of patients with pancreas carcinoma, search was made for changes in the pancreas duct epithelium and these were compared to duct epithelium in a control group of 100 pancreases from autopsies of patients with nonpancreatic cancer. The following incidences were found for pancreas cancer and nonpancreatic cancer, respectively: mucous cell hypertrophy, 39 versus 28%; pyloric gland metaplasia, 28 and 17%; epidermoid metaplasia, 6 and 12%; papillary hyperplasia, 42 and 12%; atypical duct hyperplasia, 14% and none; cancinoma in situ in 19% and none in the control group. Mucin in the majority of pancreas cancers suggested that the cell type of origin of the common pancreas cancer is the mucin-producing duct epithelium. The association of atypias and carcinomas in situ in the patients with pancreas carcinoma implies, by analogy to other organs, that there may be a significant latent period between the appearance of carcinoma in situ and the grossly recognizable pancreas cancer.