AUB-P – How do polyps contribute to abnormal uterine bleeding? – Malcolm G. Munro, MD, FRCS(c), FACOG

Endometrial and endocervical polyps are localized epithelial proliferations that possess a variable vascular, glandular, fibromuscular and connective tissue component. Typically, such polyps are attached to the epithelial surface by a narrow stalk, but, in some instances, they may have a wide base when they are called “sessile”. In the vast majority of instances the lesions are benign, but 0.5 to 4.7% of symptomatic polyps have atypical or malignant features. (1, 2)

Polyps of the endometrium and columnar cervical epithelium have long been known to be associated with abnormal uterine bleeding (AUB) but it took the wide availability of diagnostic imaging and endoscopic techniques to provide greater insight into the relationship. Using such techniques to examine asymptomatic individuals allowed us to understand that these lesions have a prevalence of 12 – 25% in “normal” populations of premenopausal women. (3, 4) Consequently, those familiar with the varied causes of AUB in the reproductive years, detailed in FIGOs new classification system, will recognize that there are a large number of potential entities, both structural, and those unrelated to visible pathology, that could coexist with asymptomatic endometrial or endocervical polyps and be the actual cause of the abnormal bleeding.(5) So, you might ask, if that is the case, which polyps contribute to AUB and which do not?

Bleeding, when it occurs, is thought to emanate from a fragile and friable vascular structure, a feature that would lead to the notion that polyp-related AUB would be a random event, manifesting in intermenstrual bleeding or spotting. Indeed the available evidence seems to support this hypothesis. (3) However, there is also some relatively high quality evidence that heavy menstrual bleeding in association with polyps also may respond to polypectomy with a measurable reduction in menstrual volume. (6)

How is the diagnosis of an endometrial or endocervical polyp to be made? We know that blind sampling with endometrial biopsy catheters or D&C is inadequate for the task and that accurate structural evaluation of the endometrial cavity requires imaging by ultrasonographic techniques and/or direct inspection with hysteroscopy. (7-9) Furthermore, while simple transvaginal ultrasound is a good screening test, it may miss some focal lesions, particularly flat polyps. Consequently evaluation for structural causes of AUB such as polyps is most reliably determined by hysteroscopy or contrast sonography).

So the “take home” message should be this: When endometrial polyps are found in women with AUB, they should be excised and sent for histopathological examination. And while polyps can be blindly removed with suitable “polyp” forceps, there is evidence that recurrence is relatively frequent when this technique is used. (10) Consequently it is preferable to remove the polyps under direct hysteroscopic visualization with one or a combination of hysteroscopic scissors, biopsy forceps, or an electrosurgical cutting loop.

More about AUB-P can be found in the book Abnormal Uterine Bleeding, from Cambridge Medical Press.(11)

1. Anastasiadis PG, Koutlaki NG, Skaphida PG, Galazios GC, Tsikouras PN, Liberis VA. Endometrial polyps: prevalence, detection, and malignant potential in women with abnormal uterine bleeding. Eur J Gynaecol Oncol. 2000;21:180-3.
2. Shushan A, Revel A, Rojansky N. How often are endometrial polyps malignant? Gynecol Obstet Invest. 2004;58:212-5.
3. Lieng M, Istre O, Sandvik L, Qvigstad E. Prevalence, 1-year regression rate, and clinical significance of asymptomatic endometrial polyps: cross-sectional study. J Minim Invasive Gynecol. 2009;16:465-71.
4. Savelli L, De Iaco P, Santini D. Histopathologic features and risk factors for benignity, hyperplasia, and cancer in endometrial polyps. American Journal of Obstetrics and Gynecology. 2003;188:927-31.
5. Munro MG, Critchley HO, Broder MS, Fraser IS. FIGO classification system (PALM-COEIN) for causes of abnormal uterine bleeding in nongravid women of reproductive age. Int J Gynaecol Obstet. 2011;113:3-13.
6. van Dongen H, Janssen CA, Smeets MJ, Emanuel MH, Jansen FW. The clinical relevance of hysteroscopic polypectomy in premenopausal women with abnormal uterine bleeding. BJOG : an international journal of obstetrics and gynaecology. 2009;116:1387-90.
7. Valle RF. Hysteroscopic evaluation of patients with abnormal uterine bleeding. Surg Gynecol Obstet. 1981;153:521-6.
8. Gimpelson RJ, Rappold HO. A comparative study between panoramic hysteroscopy with directed biopsies and dilatation and curettage. A review of 276 cases. Am J Obstet Gynecol. 1988;158:489-92.
9. Loffer FD. Hysteroscopy with selective endometrial sampling compared with D&C for abnormal uterine bleeding: the value of a negative hysteroscopic view. Obstet Gynecol. 1989;73:16-20.
10. Liberis V, Dafopoulos K, Tsikouras P, Galazios G, Koutlaki N, Anastasiadis P, et al. Removal of endometrial polyps by use of grasping forceps and curettage after diagnostic hysteroscopy. Clin Exp Obstet Gynecol. 2003;30:29-31.
11. Munro MG. Abnormal Uterine Bleeding. Cambridge: Cambridge University Press; 2010.

Abnormal uterine bleeding

Blog Post  by Malcolm G. Munro MD, FACOG, FRCS(c), Professor, Department of Obstetrics and Gynecology, David Geffen School of Medicine at UCLA, Director of Gynecologic Services, Kaiser Permanante, Los Angeles Medical Center, Los Angeles, CA, USA

Many medical students, registrars/residents, primary care physicians and even gynecologic specialists struggle when confronted with a patient with abnormal uterine bleeding (AUB) in the reproductive years. This is no surprise as both the investigation and management of abnormal AUB in such women has been hampered by confusing and inconsistently applied nomenclature and the lack of standardized methods for investigation and categorization of the various potential causes of the problem.(1, 2) Terms such as “menorrhagia” and “dysfunctional uterine bleeding” frequently have different meanings in different environments, often resulting in misinterpretation of patients, colleagues, and textbooks or the medical literature. In addition, while many potential causes of AUB are invisible such as endometrial defects or coagulopathies, many uterine entities that are discernable, such as adenomyoais, leiomyomas, and endometrial polyps, are frequently asymptomatic.