The DNA content in cells from 98 sites from 14 surgical specimens of human esophageal carcinoma, including nonpathologic epithelium; mild, moderate, and severe squamous dysplasia and squamous cell carcinoma; and in cells from 13 sites from 13 noncancerous biopsy specimens, including nonpathologic epithelium and mild and moderate dysplasia, was determined in Feulgen-stained sections by the cell analysis system (CAS 200). In surgical specimens, diploid DNA histogram patterns were observed in 16 of 17 nonpathologic epithelia, two of seven mild dysplasias, 12 of 21 moderate dysplasias, nine of 18 severe dysplasias, six of 12 intraepithelial carcinomas, and nine of 22 advanced carcinomas. In biopsy specimens, diploid patterns were observed in four of four nonpathologic epithelia, two of seven mild dysplasias, and two of two moderate dysplasias. The remaining displayed nondiploid patterns. There was a statistically significant difference in the frequency of nondiploid histogram between nonpathologic epithelium and pathologic esophageal lesions, including squamous dysplasia and carcinoma in both surgical and biopsy specimens, but not between squamous dysplasia and carcinoma in surgical specimens. We found statistically significant differences in some parameters, including the population of cells in S-phase fraction, diploid fraction, tetraploid or higher chromosome content, and peak cell number, between nonpathologic epithelium and pathologic esophageal lesions demonstrating diploid histograms. In contrast, there were no significant differences between squamous dysplasia and carcinoma demonstrating diploid histogram in those five parameters described above.(ABSTRACT TRUNCATED AT 250 WORDS)