Endometrial polyps are a relatively common pathology, occurring in 24% to 41% of women who have abnormal bleeding, and in about 10% of asymptomatic women.1,2 Endometrial polyps may be associated with leiomyomas in women who have abnormal bleeding.1-3
Polyps originate as focal hyperplasia of basal endometrium and contain variable amounts of glands, stroma, and blood vessels. Glandular epithelium has higher estrogen- and progesterone-receptor expression than surrounding endometrium, whereas the stromal component of a polyp has hormone receptors similar to endometrium. This suggests that a polyp represents focal hyperplasia that is more glandular than stromal.4
In this Update, I outline the basics of diagnosis and treatment and report on several recent investigations:
- a retrospective analysis from Italy that found that endometrial polyps are associated with advancing age and that any apparent association between polyps and diabetes, hypertension, or obesity is likely age-related
- a cross-sectional study from Norway that found that some asymptomatic polyps regress spontaneously, usually when their length is 10.7 mm or less
- three studies that explore the variables associated with premalignant and malignant polyps
- an investigation of the relationship between endometrial polyps and the background endometrium that found atypical hyperplasia in endometrium remote from the polyp in a significant percentage of women.
Age is the most important variable when assessing a patient for endometrial pathology
Nappi L, Indraccolo U, Di Spiezio Sardo A, et al. Are diabetes, hypertension, and obesity independent risk factors for endometrial polyps? J Minim Invasive Gynecol. 2009;16(2):157–162.
In this retrospective analysis of 353 women who underwent office hysteroscopy, Nappi and co-workers set out to ascertain whether endometrial polyps are associated with diabetes, hypertension, or obesity, independent of age and menopausal status. They did find an association between age, menopause, hypertension, obesity, and the presence of endometrial polyps. However, after multivariable logistic regression, all variables except age lost statistical significance. The median age at which polyps were present was 53 years (range: 29–86 years).
Details of the trial
A total of 394 consecutive Caucasian women underwent hysteroscopy to assess abnormal uterine bleeding, infertility, cervical polyps, or abnormal sonographic patterns (e.g., postmenopausal endometrial thickness >5 mm, endometrial hyperechogenic spots). Of these women, 353 were included in the study, and demographic characteristics and data on diabetes, hypertension, and menopausal status were collected. Anthropometric parameters were also analyzed. When a polyp was detected, it was removed via office hysteroscopy, and histologic analysis was performed.
The prevalence of endometrial polyps is associated significantly with age. Other associations, such as hypertension, obesity, and diabetes, exist simply because the prevalence of these pathologies increases with age. Therefore, age is the most significant variable to consider when assessing a patient for endometrial polyps.
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(4):465–471.
The treatment of asymptomatic polyps is controversial because their clinical consequences, malignant potential, and spontaneous regression rate are unknown. In this study, Lieng and colleagues prospectively estimated the prevalence and 1-year regression rate of incidentally diagnosed endometrial polyps in women 40 to 45 years old, as well as bleeding patterns and intensity.
They found polyps in 31 (12.1%) of 257 randomly selected women. At 1 year, the regression rate was 27%.
Details of the trial
At study inception, a standard 10-point visual analog scale was used to quantify each participant’s periodic bleeding, and a physical examination was performed. Transvaginal ultrasonography (US) and saline infusion sonography (SIS) were also performed. When a polyp was detected, researchers measured its length and used Doppler US to visualize the vessel feeding the polyp. An endometrial biopsy was also obtained.
The mean length of polyps was 14 mm (standard deviation [SD], 5.2 mm; 95% confidence interval [CI], 12.1–15.9; median, 13.4 mm; range, 6.7–28.7 mm), and the feeding vessel was identified for 22 of 31 polyps (71%). (For comparison, consider the findings of Clevenger and associates, who reported mean polyp diameters of 13.9 mm and 8.5 mm (P = .064), respectively, among women who had abnormal bleeding and women who did not.1)