Rectal mucosa in cystic fibrosis. Morphological features before and after short term organ culture.

Histological changes observed in the large intestinal mucosa of cystic fibrosis (CF) patients, including crypt enlargement as well as intracellular and extracellular accumulation of mucus, have been considered by some to be useful diagnostic signs of this disease. The extent of these changes, however, has not been evaluated quantitatively. In this study, quantitative stereological methods were applied to biopsies of rectal mucosa from 5 CF patients, 5 sibling controls, and 2 normal adults, to measure goblet cell numbers, crypt luminal volume, and volume of intracellular mucus. It was found that CF crypt lumina were variably dilated, but that the average relative volume of intracellular mucus and the numbers of goblet cells in CF mucosae were comparable to those of sibling and adult controls. In CF biopsies, however, surface columnar absorptive cells consistently contained putative lipid droplets and rapidly accumulated additional large lipid droplets during short term organ culture. Lipid droplets were not observed in the same cell types of control biopsies before or after short term organ culture.