Pancreatic lithiasis in the aged. Its clinicopathology and pathogenesis.

The incidence of pancreatic calculi in autopsy material was found to increase in proportion to age after 70 yr: 0% under 69 yr of age (0 of 134), 4.2% in the 70s (5 of 119), 7.7% in the 80s (9 of 117), and 16.7% in the 90s (8 of 48). Most of the stones were found scattered throughout the peripheral ducts. Pancreatic lithiasis in the aged was clinically characterized by lack of signs and symptoms, absence of alcoholism, and was unassociated with hypercalcemia. Extensive parenchymal atrophy and fibrosis were limited to the areas upstream from the calculi. The stones were found in the ducts just above the sites of obstruction where squamous metaplasia was invariably present. Immunohistologic study showed intense staining for lactoferrin in the protein plugs and in the cytoplasm of cuboidal or squamous cells of ducts containing the plugs. Ductal stenosis, either primarily caused or secondarily exacerbated by squamous metaplasia, and lactoferrin-positive cells appeared to play a role in the pathogenesis of pancreatic lithiasis in the aged.