DNA content of hyperplastic and neoplastic acinar cell lesions in rat and human pancreas

Pancreatic acinar cell hyperplastic lesions and neoplasms in rats and humans were studied for their nuclear DNA content by microspectrophotometry. Atypical hyperplastic acinar cell lesions induced in rats by azaserine displayed a wide range of DNA contents, 1.5-8C for those composed of acidophilic-type cells and 1.5-9C for those of basophilic-type cells compared with the euploid pattern of 1.5-5C in acinar cells in normal pancreas. The modal DNA values of rat acinar cell adenomas were distributed over an even wider range of 2-11C. In human pancreas, hyperplastic acinar cell lesions composed of eosinophilic-type cells displayed a slightly wider range of DNA content (1.5-8C) than that in surrounding normal acinar cells (1.5-5C). The DNA histograms of basophilic acinar cell lesions were of an aneuploid pattern (2-12C) similar to that of an acinar cell carcinoma (2-15C). These findings demonstrate that acinar cell hyperplastic lesions in rats and humans have an altered genetic complement and suggest that they probably are precursor lesions for acinar cell neoplasms.