Pathologic changes in gonadotropin releasing hormone agonist analogue treated uterine leiomyomata.

OBJECTIVE: To define the pathologic changes underlying the mechanism of shrinkage of uterine leiomyomata in patients treated with luprolide acetate.

DESIGN: Retrospective study of pathologic changes seen in leiomyomata removed by hysterectomy or myomectomy in treated and untreated patients, matched by age and size of uteri and leiomyomata.

PATIENT(S): Gross description and histologic slides of 30 treated and 30 untreated patients.

INTERVENTION(S): Histologic examination performed blindly (without knowledge of treatment). Statistical work-up using chi 2 analysis with 1 df.

MAIN OUTCOME MEASURE(S): Degree of hyaline and hydropic degeneration, cellularity, nuclear atypia, necrosis, and obliteration of interface.

RESULT(S): Confluent nodular hyaline degeneration representing a scarlike retraction, geographic hydropic degeneration necrosis and obliteration of the interface between myoma and myometrium were found in higher proportions in the treated patients; differences in cellularity, nuclear atypia, and edema were not statistically significant.

CONCLUSION(S): The decrease in size of the treated leiomyomata occurs as an accelerated postmenopausal shrinkage because of the antiestrogenic effect of the therapy. Obliterated cleavage planes may explain the difficult enucleation of myomatous nodules in some of the treated patients.