Histopathologic findings in 107 uterine leiomyomas treated with leuprolide acetate compared with 126 controls

The reported histopathologic findings in leiomyomas treated with leuprolide acetate (LA) differ. We examined 233 myomectomy specimens, including 107 myomas from 30 patients (mean age, 34.7 +/- 4.6 years) treated with LA. Their histopathologic findings were compared with those from a control group of 126 myomas from 30 untreated patients (mean age 32.7 +/- 5.3 years). The LA-treated leiomyomas had myxoid change (n = 2; 1.9%), total necrosis (n=4; 3.7%), focal necrosis (n = 5; 4.7%), calcifications (n = 5; 4.7%), hemorrhage (n = 8, 7.5%), vascular changes (n = 12; 11.2%), hydropic degeneration (n = 22; 20.5%), and hyalinization (n = 61; 57.0%). None of these changes differed significantly from the untreated controls. None of the LA-treated leiomyomas had nuclear atypia, whereas nuclear atypia occurred in four (3.2%) of the untreated leiomyomas; this difference was also not significant. Mitotic figures were present in 8.4% of the LA-treated myomas and 8.5% of untreated controls. The number of mitotic figures per 10 high-power fields was slightly higher in the untreated myomas, but the difference was not statistically significant (range, 0-3 for treated, 0-5 for controls). The degree of cellularity did not differ between the two groups. In conclusion, (a) LA-treated myomas do not significantly differ from untreated myomas with respect to nuclear atypia, calcification, total coagulative necrosis, focal coagulative necrosis, hemorrhage, vascular changes, myxoid change, hydropic degeneration, hyalinization, mitotic activity, or cellularity; and (b) the mechanism leading to a reduction in the size of myomas treated with LA is not apparent from routine histologic examination.