The proliferative potential of human pituitary tumors in situ

Abstract

✓ At the start of transsphenoidal microsurgery for removal of various types of pituitary adenomas, 21 patients received a 1-hour intravenous infusion of 5-bromodeoxyuridine (BUdR, 200 mg/sq m) to label tumor cells in the deoxyribonucleic acid (DNA) synthesis phase (S-phase). Excised tumor specimens were fixed in 70% ethanol and stained by the indirect peroxidase method using anti-BUdR monoclonal antibody as the first antibody. The percentage of BUdR-labeled cells, or S-phase fraction, was calculated for each specimen. The S-phase fraction was less than 0.1% in nine cases, 0.1% to 0.5% in seven, and greater than 0.5% in five. Except in two cases of Nelson's syndrome, in which it was greater than 1%, the S-phase fraction did not correlate with any other variable, including patient age, tumor size, or the duration of signs and symptoms. The small S-phase fraction of most of the pituitary adenomas correlates well with the clinical behavior of these tumors, which grow much more slowly than other kinds of brain...