Uterine Arteriovenous Malformations: An Underrecognized Putative Cause of Postpartum Hemorrhage, Abnormal Uterine Bleeding, and Pelvic Pain

Arteriovenous malformations (AVMs) are vascular anomalies defined by direct communications between arteries and veins with bypassing of the capillary network. Such lesions may be congenital or acquired. In the uterus, AVMs are considered uncommon, with rare case reports—predominantly in the clinical and radiology literature—citing them as a possible source of abnormal uterine bleeding (AUB) or postpartum hemorrhage (PPH). Uterine AVMs (UAVMs) are largely favored to be acquired, arising secondary to trauma (eg, prior c-section, myomectomy, curettage) or, theoretically, due to an obstructive process distorting vasculature (eg, large leiomyomata). The rarity of reported cases to date has yielded an estimated incidence of 0.10% among premenopausal women. However, the personal experience of 2 academic gynecologic pathologists suggests a higher incidence of incidentally discovered uterine UAVMs. The aim of this study is to highlight the clinicopathologic features and putative etiologies of a series of UAVMs. Clinical presentations, gross findings, and histologic features of 12 UAVMs diagnosed from 2018 to 2023 from 2 institutions were reviewed. Cases arose in both premenopausal and postmenopausal women (range 24–55 yr) and were diagnosed as part of routine, nonconsultative practice. All patients were status post hysterectomy for benign pathologies (eg, leiomyomata, adenomyosis, endometriosis, postpartum hemorrhage), with the most common clinical presentations being chronic pelvic pain (n=6) and AUB (n=5). Histologically, all cases demonstrated incidentally discovered AVMs, hallmarked by the presence of an admixture of small to medium-sized arteries and veins without an intervening capillary network, arising in both the uterine cervix and corpus. Immunohistochemistry was pursued in select cases, which demonstrated an admixture of ERG and CD31-positive vasculature in the lesional foci. Most putative etiologies for AVM formation were obstructive (n=6), followed by a combination of obstructive and prior uterine intervention (n=4), prior uterine intervention only (n=1) and syndromic association (n=1). We demonstrate that UAVMs are likely an underrecognized cause of AUB, PPH, and chronic pelvic pain and often arise in the setting of obstructive benign pathology (eg, leiomyomata). Recognition of UAVMs, both clinically and pathologically, is important in determining the etiology of otherwise unexplained AUB and chronic pelvic pain. Uterine Arteriovenous Malformations: An Underrecognized Putative Cause of Postpartum Hemorrhage, Abnormal Uterine Bleeding, and Pelvic Pain - Buy - PAP Plain Language SummaryUterine arteriovenous malformations (UAVMs) are rare vascular anomalies that can cause abnormal uterine bleeding (AUB) and chronic pelvic pain. This study reviewed 12 cases of UAVMs diagnosed between 2018 and 2023, finding them in both premenopausal and postmenopausal women who had undergone hysterectomy for benign conditions like leiomyomata and adenomyosis. UAVMs were often discovered incidentally and were linked to obstructive processes or prior uterine interventions. The study suggests UAVMs may be more common than previously thought and highlights the importance of recognizing them to better understand unexplained AUB and pelvic pain. Text is machine generated and may contain inaccuracies. FAQ