It was revealed that the sensitivity and specificity of MSI data distinguishing ACTH secreting adenomas from nonpathological pituitary were 100% and 93%, the sensitivity and specificity of MSI data distinguishing GH secreting adenomas from nonpathological pituitary were 82% and 100% and the sensitivity and specificity of MSI data distinguishing PRL secreting adenomas from nonpathological pituitary were 50% and 100%, respectively. The gene discussed is GH1; the disease is adenoma.