The diagnostic significance of parabasal cells. II. Rate of their disappearance and reappearance under estrogen administration and withdrawal.

The rate of disappearance of parabasal cells under estrogens and their reappearance following the cessation of treatment was studied in 22 patients. In ten patients with complete atrophic cell type, parabasal cells disappeared within 6 to 15 days under the influence of estradiol dipropionate (1-0.5-0.05 mg. daily for five days). In these patients parabasal cells reappeared promptly (within 20 days) after discontinuation of estrogen administration. In 12 patients receiving replacement therapy for long periods of time (2 to 10 years) there was a marked variability (10 days to 8 months) in the rate of reappearance of parabasal cells after cessation of treatment. These findings document the sensitivity and reliability of the atrophic cell type as an index of estrogen lack in the organism.