Production of collagen fibrils in adrenocortical adenoma with Cushing's syndrome.

The production of collagen fibrils, especially collagen type III, was studied with regard to eight adrenocortical adenomas with Cushing's syndrome. Anti-type III procollagen amino-terminal peptide serum (procollagen III) was employed for the PAP method. In areas of clear-type cells, the parenchymal cells were negative for procollagen III, but the stroma exhibited an intense reactivity and were arranged in an alveolar fashion. On the other hand, it was obvious that not only interstitial cells or spindle-shaped cells but also the parenchymal cells synthesized procollagen III in areas of compact-type cells, and the stroma showed a strongly positive reaction to it.