The trans-vaginal US examination does not reveal any polyp in this patient
with post menopausal bleeding. The endometrium (E) is thickened. The HSG
demonstrates the polyp (P) in the endometrial cavity
Hysterosonography is superior to endovaginal US in the evaluation of the
endometrial thickness in patients with post-menopausal bleeding. By hysterosonography
one can differentiate sub-endometrial lesions from endometrial lesions.
It is an excellent procedure to demonstrate changes related to tamoxifen
therapy on the endometrium.
Women with postmenopausal vaginal bleeding are diagnosed by HSG to have
polyps and sub-endometrial fibroids. A small percentage of women are diagnosed
with endometrial cancer. An endometrial thickness of 4 or 5 mm or less
almost completely excludes endometrial carcinoma. HSG has been shown to
be useful for evaluating the endometrium, particularly in patients with
PMB. Even when the endometrial thickness is 5 mm or less, HSG is accurate
in identifying an anatomic cause of the bleeding in some cases.
In the general population, endometrial polyps are composed of three components:
(a) stroma of dense fibrous tissue, (b) thick-walled vascular channels,
and (c) endometrial glands. The incidence of endometrial polyps is higher
in women treated with tamoxifen than in untreated women: 8%–36%
versus 0%–10%. Although these polyps may cause abnormal uterine
bleeding, most women are asymptomatic.
"Tamoxifen" induced polyps are larger and are differentiated
from the ordinary type by the proliferative process seen as cystic glandular
dilatation, and aberrant epithelial differentiation or metaplasia. If
periglandular stromal condensation seen, it may be a form of müllerian
adenosarcoma. Extensive stromal fibrosis within the polyp may make resection
difficult at hysteroscopy.