Pathological characteristics and clinical outcome of uterine leiomyomas associated with pregnancy.

Classification of a uterine smooth muscle neoplasm as benign or malignant is straightforward in most of the cases. During pregnancy, hemorrhage, necrosis and various degenerative changes can complicate the diagnosis. In this study, we examined the histological features, clinical behavior and proliferatively related markers in gestational leiomyomas removed during cesarean section. From 2005 to 2008, 53 pregnant patients with leiomyomas were submitted to cesarean section in our institute. Degenerative and atypical changes were detected in 42 leiomyomas (61.7%). Seven leiomyomas had extensive areas of necrosis. All necrotic foci appeared in the form of hyaline type or infarct type necrosis. Cellular atypia was mild and focal in 18 leiomyomas. Atypia was associated with hyaline type necrosis in 3 cases. Mitotic activity was very low (<5/10 HPF) in one but all of the cases. Within a median follow-up of 38 months, none of the patients in our study with follow-up information had any evidence of residual disease or recurrence. Morphological features of leiomyomas removed during pregnancy include extensive hyalin type necrosis, hemorrhage and focal cellular atypia. The pathological management of gestational uterine leiomyomas may be performed successfully with a multivariate diagnostic approach. The proper clinical management of leiomyomas needs further studies to clarify the etiology and pathogenesis of this common disease.