Benign Tumours Flashcards
What are fibroids?
Fibroids are extremely common benign monoclonal tumours of the smooth muscle cells of the uterine myometrium, containing a large amount of extracellular matrix with disordered collagen. They start as multiple, single-cell seedlings distributed throughout the uterine wall. These then increase in size very slowly over many years, stimulated by oestrogens and progestogens. As the fibroid grows, the central areas may not receive an adequate blood supply and undergo benign degeneration often followed by calcification
What causes fibroids?
The cause of fibroids is debated but it is thought to be a combination of acquired genetic change plus the effects of hormones and growth factors, possibly related to a response to ischaemic injury at the time of menses.
Name the types of fibroids:
Intramural (the majority).
Submucosal: growing into the uterine cavity. They may be pedunculated and may protrude through the cervical os.
Subserosal: growing outwards from the uterus - can be:
- Uterine
- Cervical
- Intraligamentous
- Pedunculated subserous (abdominal)
Name some symptoms of fibroids:
Most uterine fibroids are asymptomatic (up to half).
But they can cause;
-Prolonged or heavy menstrual bleeding (can lead to anaemia- fatigue etc).
-Pelvic pressure or pain
-Fibroids may present with recurrent miscarriage or infertility. However, only submucous fibroids decrease fertility but their removal restores fertility to baseline rates.
-Pedunculated submucosal fibroids may cause inter menstrual bleeding
-5% of pregnant women noted to have fibroids experience acute pain during the pregnancy, due to fibroid degeneration.
-Pressure on the bowel may cause constipation and pressure on the bladder may cause urinary
symptoms.
-Dyspareunia
Fibroids don’t undergo malignant change to a sarcoma except in very rare circumstances but tumours assumed to be benign fibroids may occasionally later be identified as uterine sarcomas. Most women with sarcoma have symptoms of a suspected gynaecological malignancy: abdominal pain and abnormal bleeding.
How common are fibroids?
- Uterine fibroids are the most common non-cancerous tumours in women of childbearing age, occurring in 77% of women. They are clinically apparent in 25%.
- Fibroids are three times more common in African-American women than in white Americans. Black women tend to be younger at the time of diagnosis and have more numerous, larger and more symptomatic fibroids.
What age do fibroids tend to present?
Although they have been reported occasionally in adolescents, most women are in their 30s or 40s when the myomas become symptomatic. The incidence increases with age up to the menopause.
Examination required when suspecting fibroids:
Examination:
Palpable abdominal mass arising from the pelvis.
Enlarged, often irregular, firm, non-tender uterus palpable on bimanual pelvic examination.
Signs of anaemia due to menorrhagia.
Ddx for fibroids?
- Dysfunctional uterine bleeding.
- Endometrial polyps, endometrial cancer.
- Endometriosis.
- Chronic pelvic inflammatory disease.
- Tubo-ovarian abscess.
- Uterine sarcoma.
- Ovarian tumour.
- Pelvic masses (other causes of a pelvic mass include t-tumour of the large bowel, appendix abscess, and diverticular abscess).
- Pregnancy.
Investigations needed in suspected fibroids:
- Pregnancy test if chance of pregnancy
- FBC (anaemia), iron studies.
- Pelvic ultrasound may be indicated to exclude other causes of a pelvic mass, to confirm the presence and size of a fibroid and to exclude possible complications such as urinary tract obstruction causing hydronephrosis. Transvaginal ultrasound (TVUS) is more accurate.
- MRI is highly sensitive and specific and is occasionally required if ultrasound is not definitive in assessing the fibroid(s) when myomectomy is being considered.
- Endometrial sampling (Pipelle®): for histology in the assessment of abnormal uterine bleeding.
- Hysteroscopy: with biopsies.
- The combination of lactic acid dehydrogenase (LDH), LDH isoenzyme 3 and gadolinium-enhanced MRI is highly accurate in diagnosing leiomyosarcoma pre-operatively, if sarcoma is suspected clinically.
Management of fibroids:
Only required if symptomatic. Symptoms will usually reduce/ stop post-menopause.
-Non-steroidal anti-inflammatory agents (eg, ibuprofen) may be tried. They reduce menstrual blood loss when the cause is unknown due to reducing prostaglandins. Antifibrinolytic agents (eg, tranexamic acid) may also also reduce menorrhagia.
-Combined hormonal contraception pill (CHC). This is helpful if the patient requires contraception, although it is not as effective as a levonorgestrel-releasing intrauterine system LNG-IUS (Mirena®)
-Gonadotrophin-releasing hormone (GnRH) agonists:
Produce reduction in the size of fibroids, in the region of 50% within three months but, once discontinued, fibroids regrow to their former size within about two months; therefore, they are mainly useful pre-hysterectomy.
- Mifepristone is a progesterone receptor inhibitor which is effective at reducing fibroid-related bleeding but, as it results in exposure of the endometrium to unopposed oestrogen, it may cause endometrial hyperplasia. It does not reduce uterine volume and hence has no role pre-surgery.
- Ulipristal acetate: A selective progesterone receptor modulator (SPRM), with predominantly inhibitory action. It acts by inhibiting cell proliferation and inducing apoptosis. It has been shown to be superior to placebo and non-inferior to GnRH agonists. Like mifepristone however, long term endometrial safety data are still required before SPRMs can be used other than pre-surgery. The licensed indication is for pre-operative treatment and duration of treatment should not exceed two three-month courses. Measure LFTs once monthly for patients on this.
Risk factors for fibroids:
Fibroids are more common in obese women and women with an early menarche - factors which increase lifetime exposure to oestrogen.
Protective factors against fibroids:
Exercise and increased parity are protective factors.
Surgical indications for fibroids:
- There is excessively enlarged uterine size.
- Pressure symptoms are present.
- Medical management is not sufficient to control symptoms.
- The fibroid is submucous and fertility is reduced.
Surgical options for fibroids:
Myomectomy - this is used in patients who wish to maintain their reproductive potential or keep their uterus. Abdominal myomectomy is a safe alternative to a hysterectomy. However, there is a risk of excessive bleeding and a risk of requiring hysterectomy at the time of the operation. Therefore, blood should be cross-matched pre-operatively and the patient needs to give their consent to hysterectomy should the need arise. Lapascopically is associated with lower risks.
Hysteroscopic endometrial ablation - for women presenting with menorrhagia.
Total hysterectomy: This has been the mainstay of treatment for many years, eliminating both symptoms and the possibility of recurrence. It is also indicated when there are many fibroids. If these are small then the vaginal route is appropriate but if they are large (especially if intraligamentous) then laparotomy is indicated with preservation of ovaries if possible. Blood loss may be reduced by preceding use of GnRHas.
Uterine artery embolisation (UAE): This procedure has been shown to be both effective (for short- and medium-term symptom relief) and safe for women who wish to keep their uterus, although the effects on fertility and pregnancy are uncertain. Ensuring the tumour is a benign fibroid and not a malignant sarcoma is essential prior to UAE.
MRI-guided transcutaneous focused ultrasound.
Name the three types of ovarian tumours:
- Functional 24%
- Benign 70%
- Malignant 6%
