Endometrial polyps
Definition:
Localized hyperplasic overgrowths of endometrial glands and stroma which form projections from the surface of the endometrium
- can be single or multiple
- Range from a few millimetres to several centimetres.
- incidental endometrial polyps are diagnosed more frequently
INCIDENCE:
- rare among women under the age of 20 years
- Rises steadily with increasing age, peaks in the 5 decade of life and gradually declines after the menopause.
- 24–41% with abnormal uterine bleeding, 10% of asymptomatic women are diagnosed with endometrial polyps
- an increased incidence of endometrial polyps in women on hormone replacement therapy (HRT) and tamoxifen (8–36%), acts as a selective receptor modulator and estrogen agonist on the endometrium.
- endometrial polyp formation appears to be related to the type and dosage of the estrogen and progestogen in HRT
- higher incidence of concurrent endometrial hyperplasia with endometrial polyps, especially in women on hormone replacement,
aetiology
- unknown
- close relationship with the background endometrium
- Proliferate and express apoptosis-regulating proteins during the menstrual cycle.
- In both pre and postmenopausal women, endometrial polyps lose their apoptotic regulation and over express estrogen and progesterone receptors, thus avoiding the usual control mechanisms.
- Genetic factors may explain polyp development, identifying clusters of anomalies in chromosomes 6 and 12, which may alter the proliferative process, resulting in polyp formation in some women
- Other risk factors include obesity and hypertension.
SYMPTOM
- generally asymptomatic
- present in approximately 1/4th of symptomatic pre and postmenopausal women
- ½ th of the premenopausal women may present with menorrhagia
- postmenopausal bleeding,
- prolapse through the cervical ostium,
- abnormal vaginal discharge
- Breakthrough bleeding during hormonal therapy.
- Symptoms do not appear to correlate with the polyp number, size or location.
INVESTIGATION
- ultrasound,
- saline infusion sonogram
- Hysteroscopy – gold standard.
Transvaginal ultrasound scanning (TV USS)
Not superior to SIS
Likelihood ratios for a positive – 2.7 for TV USS and 15.5 for SIS.
Likelihood ratios for a negative – 0.46 for TV USS and 0.07 for SIS
Findings:
- hyperechoic lesions with regular contours within the uterine cavity,
- surrounded by a thin hypo-echoic halo
- Cystic spaces may also be present and correspond to dilated glands filled with proteinaceous fluid.
- a single feeding vessel to a suspected polyp has been demonstrated to confirm the presence of a polyp with a specificity and NPV of 95% and 94% respectively
Colour Doppler can be used to differentiate between endometrial polyps and submucosal fibroids and it may also be helpful to distinguish between benign and malignant pathology.
Saline infusion sonogram (SIS),
- uses a sterile normal saline solution to distend the endometrial cavity & outline polyps,
- highly sensitive,
- well-tolerated,
- safe,
- Rapid and minimally invasive diagnostic technique.
- may help in predicting endometrial malignancy of a focal lesion
- Distension difficulties should also raise a suspicion of malignancy.
Gel instillation sonography (GIS)
- an alternative to SIS.
- Fewer technical failures.
Saline contrast hystero sonography
- accurate in evaluating the uterine cavity of pre- and postmenopausal women suffering with abnormal uterine bleeding
- fails more often in postmenopausal women compared with premenopausal women due to stenosis of cervix, backflow or distention problems.
- There also seems to be a learning curve to perform the procedure, which once acquired, should reduce the failure rates to around 10%
Hysteroscopy
sensitivity of 100%
specificity of 97%,
Accuracy of 91%
Allows for concurrent treatment
Hysteroscopic markers for malignant endometrial polyps à indications for histological diagnosis.
- surface irregularities such as necrosis,
- vascular irregularities
- whitish thickened areas
hysteroscopic polypectomy improved the rate of spontaneous conception regardless of size or number of polyps, which may be due to the normalisation of endometrial implantation factors in infertile woman.
Treatment
Malignant potential are rare.
Malignant potential increases with endometrial polyp size, symptoms and patient age.
these factors need to be considered in mx
Suggested treatment algorithm for women with endometrial polyps based on current evidence
- endometrial polyps in postmenopausal women are more likely to be malignant when symptomatic so have to under go resection
- even risk of malignant transformation is low, endometrial polyps should be removed when detected, as excision allows for both histological diagnosis and effective treatment of abnormal uterine bleeding patterns and excessive menstrual loss
- Incidental small endometrial polyps in premenopausal women may be amenable to conservative treatment due to their low malignant potential and chances of regression. (one obseversional study)
- The risk of perforation during hysteroscopy is higher in asymptomatic women.
Hysteroscopic resection
Good direct and circumstantial evidence that hysteroscopic resection of endometrial polyps under vision is safe, simple and superior to blind techniques:
- Malignant cells at the base of the polyp can be missed with blind avulsion.
- Hysteroscopic resection avoids excessive cervical dilatation, which is when uterine perforation and creation of a false passage usually occur.
- Not a single recurrence of endometrial polyps was reported when resection under vision was compared with removal with a grasping forceps (recurrence rate 15%).
Resection is feasible even in an outpatient setting without general anaesthesia, which has become possible due to small- diameter instruments, which obviate the need for cervical dilatation.
See-and-treat outpatient hysteroscopy is cheaper than inpatient hysteroscopy under general anaesthesia.
Adequate patient selection, psychological support, a competent operator and a setting that creates a private, caring and calm environment are prerequisites for carrying out this procedure in the outpatient setting.
The vaginoscopic approach to hysteroscopy causes less pain than the traditional approach using a speculum and tenaculum but is similarly successful in achieving polypectomy
The procedure is carried out as follows in out patient:
- NSAID or tramadol are given orally 1 hour prior to the procedure,
- Can be carried out at any time during the cycle unless the women are bleeding heavily, without the need for routine antibiotic cover.
- in the lithotomy position
- a staff member providing one-to-one attention, vaginoscopy is carried out.
- hysteroscopy system consisting of scope and a sheath with a 3.5 mm expandable operating channel is inserted into the posterior vaginal fornix under normal saline irrigation.
- The cervix is then ‘loaded’ onto the hysteroscope and during gentle withdrawal of the hysteroscope the cervical canal moves into the field of vision.
- After allowing time for cervical hydrodilatation the scope is gently navigated through the cervical canal with minimal lateral movement and tissue contact.
- Once the endometrial polyp is visualised the hysteroscope is adjusted by moving the sheath to allow good access to the endometrial polyp base from the operating channel.
- endometrial polyps are resected with cold scissors down to a thin stalk and then retrieved under vision with a hysteroscopic grasper or Bipolar electrosurgical resection with bipolar twizzles or polyp snares also show good success and low pain scores.
- Polyps >2 cm require piecemeal removal, a longer operating time and multiple instrument passes through the cervix. In those cases we recommend removal under general anaesthesia, but small-diameter hysteroscopic morcellators are becoming available for this indication.
Failure of outpatient hysteroscopy due to:
- anatomical factors, including cervical stenosis,
- inadequate visualisation
- patient tolerance – inform that outpatient hysteroscopy is acceptable to most women and that, on average, it is considered less painful than menstruation.
Biopsy of adjacent area after polypectomy?
Referrence
TOG 2012
TOG 2015
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