[Kidney adenoma].

Morphological, electron microscopic, histospectrophotometric and morphometric (mean nuclear surface and ellipticity coefficient) studies of small cortical adenomas were performed. Surgical (kidneys removed because of renal cell carcinoma and shrinkage) and autopsy (atrophic kidney) materials were used. Total 142 adenomas were found in 93 out of 592 observations. The incidence of adenomas in kidneys with renal cell carcinoma was 12%, in contracted kidneys 19.2 and 19.44% (surgical and autopsy material). Electron microscopic examination was performed in 15 adenoma cases. Comparative quantitative DNA determination was performed in sections stained by Feulgen using plug-method on the microscope spectrum analyzers in 20 cases of adenoma and 15 cases of renal cell carcinoma identical histologically to adenocarcinoma. This combined study revealed the adenomas heterogeneity. Only part of them (well differentiated with diploid DNA-histograms and nuclei up to 32 mm2 may be referred to adenomas. All the others morphologically and morphometrically are close to adenocarcinomas. The type of DNA distribution and mean nuclear surface are most important for differential diagnosis between renal adenoma and carcinoma.