Endometrial polyps detected at ultrasound and rate of malignancy

The vast majority of the evidence on the prevalence of malignancy in endometrial polyps was obtained irrespectively of the time of diagnosis, i.e. including both women who were diagnosed at pre-surgical ultrasound and those who were diagnosed at the time of hysteroscopy. We hypothesize that this may represent an inaccuracy of potential clinical relevance since physicians have to take decisions regarding the need of surgery at the time of ultrasound diagnosis.

Medical records of 2,245 patients who underwent hysteroscopy during a 4-year period were reviewed. Inclusion criterion was a pre-operative diagnosis of endometrial polyps.

1,284 women (57 % of the cohort) were selected, of whom 36 were diagnosed with malignancies (2.8 %, 95 % CI 2.0-3.8). This prevalence markedly differ in pre- and post-menopause, being higher in the latter group (OR = 9.0, 95 % CI 2.6-30.3, p < 0.001). Six out of 803 resulted positive in the pre-menopausal group (0.7 %, 95 % CI 0.3-1.5) compared to 30 out of 481 in the post-menopausal group (6.2 %, 95 % CI 4.3-8.6). In the pre-menopausal group, a younger age resulted protective. The risk of malignancy in women younger than 50 years was 0.3 % (95 % CI 0.04-0.9). In the post-menopausal group, abnormal uterine bleeding (AUB) was associated with a diagnosis of malignancy (OR = 4.0, 95 % CI 1.9-8.5). The prevalence of malignancy in symptomatic and asymptomatic post-menopausal women was 11.8 % (95 % CI 7.6-17.1) and 3.0 % (95 % CI 1.4-5.3), respectively.

The prevalence of malignancy among endometrial polyps detected at ultrasound is low and in line with the evidence obtained for a diagnosis made at the time of surgery. Some simple anamnestic information such as menopausal status, age and AUB helps identify women at higher risk and should be used in the decision-making process guiding the choice of surgery.