Pancreatic PP cell distribution and hyperplasia. Immunocytochemical morphology in the normal human pancreas, in chronic pancreatitis and pancreatic carcinoma.

Abstract

The endocrine pancreatic tissue from 13 patients with severe chronic pancreatitis, 5 patients with pancreatic duct carcinoma and 4 non-diseased pancreases was analysed by immunocytochemistry and morphometry. The controls revealed two distinct islet types with different regional distribution. The lower dorsal part of the pancreatic head contained islets with irregular outlines and a high number of PP cells (PP-cells 60.4±4.1%; B-cells 29.4±4.6%; A-cells 7.4±1.5%; D-cells 2.8±0.6%). The other parts of the pancreas contained compact islets with only a few PP cells (PP-cells 1.0±0.4%; B-cells 69.3±3.0%; A-cells 24.1±2.1%; D-cells 5.8±0.5%). In chronic pancreatitis the sclerotic tissue of the body and the tail region contained compact islets with altered cell inter-relationships when compared with controls. While the number of B-cells was diminished (48.5%), A and PP cells appeared to be increased in number (42.7 and 4.1%, respectively). Furthermore, ductulo-insular proliferations were conspicuous (nesidioblastosis) with budding-off of small endocrine cell clusters made up predominantly of A and PP cells. In 3 patients with pancreatic carcinoma increased numbers of PP cells and of A cells were found along the advancing edge of the carcinoma.