Pathologic features of uteri and leiomyomas following uterine artery embolization for leiomyomas

The objectives of this study were to identify the presence/absence and location of any embolic material and to describe the morphologic appearance of the leiomyoma and adjacent tissues of cases undergoing surgical intervention following uterine artery embolization (UAE) for leiomyomas. A total of 555 women underwent UAE using polyvinyl alcohol particles (PVA) in a multicenter clinical trial. The histopathologic slides from 17 of 18 women who subsequently underwent myomectomy or hysterectomy in the follow-up period (median 8.2 months) were reviewed without knowledge of the indication for surgery or time elapsed since UAE. The presence/absence and distribution of PVA emboli, associated inflammatory response, and necrosis were noted. Necrosis of leiomyoma(s) was classified as hyaline-type, coagulative tumor cell necrosis, and/or acute suppurative necrosis. In all cases PVA emboli were identified within smooth muscle tumors of the uterine body, its periphery, cervix, uterine body, myometrium, and/or the adnexa. A florid foreign body giant cell type of chronic inflammatory reaction was seen within 1 week of UAE and persisted with visible PVA for up to 14 months post-UAE. Typically, post-UAE leiomyomas showed hyaline-type, but rarely coagulative tumor cell necrosis and acute suppurative necrosis could be seen as well. Five of eight cases coming to surgery for complications showed necrotizing endomyometritis with tissue infarction. PVA particles are recognizable in post-UAE specimens. Leiomyoma necrosis is typically of the hyaline type; coagulative tumor cell necrosis was rarely seen. In some cases with complications, uterine and/or cervical necrosis occurred. The applicability of these findings for UAE patients who have been successfully treated and not resected is uncertain.