Endometrial polyp (review) - JS Afonso

This link was last updated on October 01, 2003 and review on July 20, 2005.

This article should be cited as:

Afonso JS. Endometrial polyp (review). In: http://www.histeroscopia.med.br/. Access in:

keywords: hysteroscopy, endometrial, polyp.

José Sebastião Afonso




From the outside their appearance is velvety, smooth, red or orange masses. They are oval-shaped of elongated sessile or pedicular tumourous formations. Inside it is solid or contains cysts. They are born in the endometrium and project themselves into the uterine cavity, and ulcerate and bleed very easily. They vary a lot in terms of volume and number: from minimal to the point of filling the whole of the uterine cavity, singly or as a group. Most of them have a diameter of between 2 and 4 cm in the most (Bogliolo ,1976).

Kindly offered by Dr. Antônio Francisco de Souza

(PhD from the Escola Paulista de Medicina, Prof. of Pathology of the Universidade Federal de Minas Gerais, Head of Pathologic Anatomy of the Hospital Luxemburgo of Belo Horizonte).


"Hyperplastic growth of the glands and stroma"  (Kistner, 1989).

"Endometrial glands covered by pseudo-stratified epitelium, juxtaposed and with cystic areas, inserted in fibro-vascular stroma"  (Bogliolo, 1994).

The polyps hold a varied number of glands, stromas and blood vessels.

"In the majority of cases the hystologic situation is the simple hyperplasia of the uterine mucous membrane; at times, almost every gland is dilated (cystic hyperplasia)" (Bogliolo, 1976).

Most of them present an immature basal endometrium hystological pattern, which in general does not respond to hormonal stimulus (Kistner, 1989).

The hystological pattern can be described as atrophic and hyperplastic (Muylder, 1999).

The typical effects of tamoxifeno in the endometrial polyp are: perigladular  stromal condensation, epithelial metaplasia and atypical formations in different degrees (Ismail, 1994).

In morphological terms the endometrial polyps can be classified as:

1)  Hyperplastic polyps - respond to strogen and are similar endometrial  diffuse hyperplasy.

2)  Functional polyps - present glandular alterations similar to those of the  surrounding endometrium.

3)  Adenomimatose polyps - when a significant amount of muscular tissue is identified.

4)  Atrophic polyps - they result in retrogressive alterations of a hyperplastic or functional polyp.

5)  Pseudo-polyps  - small size (less than 1cm), sessile, with a structure similar to that of the surrounding endometrium. They are only identifiable durin the secretory phase and disappear with menstruation.

Frequency, Incidence and Etiology

They are found in about 10% of the uteruses examined during autopsy.

The peak age is between 40 and 50 (Lima, R. et al., 1979).

In a recent retrospective study Bacsko G. and Major T. (1999) found 163 polyps in 1,900 hysteroscopic procedures. Those patients presenting previous  D&C  corresponded to 22%. Hysteroscopic procedures indicated haemorrhage in 55%, abnormal USG in 25% and sterility in 15%.

Their etiology is unknown. They start as local proliferation of the endometrial tissue covered by epithelium. Strogen's real involvement, with no progesteron opposition, is still unknown.

A genetic alteration was found involving chromosomes two and twelve.

A good number of studies have reported an increased incidence of endometrial polyps and carcinomas in patients that use tamoxifeno in the treatment of mammal  cancer.

This can be partially attributed to other factors.

Vilodre et al (1997) observed that age and cervical polyps were independent risk factors for endometrial polyps. This study did not show a significant relationship concerning parity, cigarette smoking or contraceptive pills.


The polyps are generally assymptomatic.

The most common symptom is irregular bleeding that does not respond to the clinical treatment. Its manifestation can come in the form of a haemorrhage  morbid discharge after the menstrual period, with a duration of 4 to 5 days (Kistner, 1989).

Kamel H. S. et al (2000) have demonstrated that sonohysterography  is more significantly accurate than transvaginal ultrasonography in detecting endometrial polyps in the cases of abnormal uterine bleeding. A combination of the two techniques has not improved accuracy. The ultrasonography presented a positive rate of 25% and a fake negative rate of 36.2%.

The polyps appear in the ultrasonography in the form of a non-specific endometrial thickening or of glandular and cystic floating structures (Muylder, 1999).

Uterine curettage does not usually remove the lesion, and the endometrium obtained shows signs of hyperplasia which confuses diagnosis.

"The endometrial polyps respond for 34% of the diagnosis overlooked by D & C" (Copeland, 1993).

The  hysterosalpingography shows a poorly defined image that does not didtort the uterine cavity. Small polyps have not been observed.

"Hysteroscopy is the most sensitive of all diagnostic tests and has been recommended as the initial stage in the evaluation of normal uterine bleeding" (Copeland, 1993).


In a retrospective study Bacsko G. and Major T. (1999) demonstrated the high rate of fake positive in hysteroscopy. The result of the hystologic test  in 153  'polyps' was quite surprising. It showed 22 cases of proliferative endometrium, 17 cases of hyperplasia, 6 cases of secretory endometrium, 5 cases of fibroma and hormonal malfunction and 1 case of endometritis, adenomiosis, atrophy and  malignant transformation.

In hystopathology Lass A. et all (1999) confirmed 58% of the endometrial polyps diagnosed by hysteroscopy. In the same study it was demonstrated that polyps smaller than 2cm do not lower the rate of pregnancy in the in vitro fertilization, but the tendency is for failed pregnancy.

Hysteroscopic morphology according to  Hamou:

Mucous Polyp - Like the pseudopolyps, they can be sessile or pediculated. They are bigger than 1cm and mobile. In appearance, they are similar to the surrounding endometrium and are frequently congested. They can be single or multiple.

Fibrous Polyp -  usually pediculated, smooth, mobile and do not easily deform with the pressure exerted by the tip of the hysteroscope. Its surface, when evaluated in the magnitude 20x, is smooth, with very few blood vessels and does not identify with glandular openings.


The endometrial polyps can be removed by hysteroscopic eletroresection, with the use of the same technique used in myomectomy - a relatively easy procedure.

Hysteroscopic electroresection stems from the resection technique used for the prostate gland.

The ideal stage is that of initial proliferation.

The incision is always performed through the direct method (visualization), in the direction uterine fundus to the cervical channel.

The loop is fixed at a distance from the resectoscope and the instrument as whole moves in the same fashion as a curette. The movement  can also be combined when the person performing the procedure is more experienced  (loop + curette movement).

What follows if the "slicing" of the polyp up to the miometrium, which is easily identifiable in when magnified 20x by the fasciculated structures. 

Bleeding in general is insignificant, yet at the end we clotted the wound left by the surgery.

Perez-Medina T. (1999) avoided removing he polyps in patients that did not present the symptoms and whose USG vaginal Doppler was negative. After three years the segment showed that the patients remained clinically asymptomatic  and with a negative USG vaginal Doppler.

In a retrospective study Bacsko G. e Major T. (1999)showed that during 153 polipectomies there were 2 perforations and no major complications.

Recurrence in unusual. 

Adenocarcinoma and Malignant Potential 

The malignant potential of endometrial polyps is rather low.

Isolated focuses of neoplastic growth are rarely found.

Endometrial cancer associated polyps in women in a post-menopause stage is between 10 and 34%. 

Women with endometrial polyps are twice as much in danger of having endometrial cancer (Petterson et al., 1985).

Polyps with atypical hyperplasia are lesions that appear prior to endometral cancer (age peak between 50 and 70) 


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