The correct term for a fibroid is a leiomyoma. It is estimated to be the most common tumour in the human body being present in approximately 20 per cent of women at autopsy. Hence the general surgeon is likely to encounter a uterine fibroid more than once in his/her career in more than one presentation.

The aetiology of fibroids is unknown but the main contender is the stimulation provided by unopposed oestrogens. They are more common in women who have not borne children and in women of negro origin. The latter tend to develop fibroids when young even despite having borne children. In women of European origin fibroids tend to cause symptoms from around the age of 30 years onwards. After the menopause they atrophy in most cases, due both to decreased oestrogen levels and blood supply. In 10 to 15 per cent of cases, fibroids are found together with endometriosis which can make surgery difficult.

Macroscopically the appearance is of a firm round tumour in the uterine wall, which itself may be thickened and hypertrophied. The tumours usually arise in the body of the uterus or less commonly, in the cervix; infrequently, they arise from the round ligaments. Fibroids within the wall of the uterus are described as being intramural, if projecting from the peritoneal surface of the uterus; as subserous, if between the layers of the broad ligament; as intraligamentary; and if projecting into the uterine cavity as submucous (Table 1) 409. Subserous fibroids may become pedunculated (Fig. 1) 1451 and submucous ones polypoid, even protruding through the external cervical os. Pedunculated fibroids maybe become adherent to other structures, particularly the omentum, gain a second blood supply, and lose their uterine attachment; they are then termed parasitic. Fibroids arising in the cervix or intraligamentary fibroids may displace the ureters sometimes quite a distance from their normal position, placing them at risk during surgical removal.

Fibroids may be single or multiple. Their size varies from microscopic to a size large enough to fill the whole abdomen. Characteristically they are firm but as a result of degeneration may be soft and cystic, or rock hard when calcified. They have a false capsule of compressed uterine muscle. The blood supply enters from the periphery and thus fibroids are relatively avascular.

Various degenerative changes, encouraged by poor blood supply, occur in fibroids. These include hyaline degeneration, cystic degeneration, calcification, necrosis, red degeneration, sarcomatous degeneration, and infection. Other rare complications such as benign metastases in the lung, and an association with polycythaemia have been described.

The more important changes from the surgeon's point of view are red degeneration, calcification, and sarcomatous degeneration. Calcification is most often seen in pedunculated fibroids or in women well beyond the menopause. The fibroids becomes rock hard and will show up on radiography as a calcified mass. Red degeneration (Fig. 2) 1452 most often occurs in pregnancy or near the menopause. It is similar to the process of infarction and gives rise to severe pain. Sarcomatous degeneration is a very infrequent occurrence (1:1000 up to 8:1000), although about two-thirds of uterine sarcomas do arise in fibroids. The median age of presentation is in the late forties. A better prognosis is reported for premenopausal women. A rapid, painful, increase in size of a fibroid can be a suspicious sign of sarcomatous change. The treatment is total hysterectomy and bilateral salpingo-oophorectomy. Five-year survival rates vary from 20 to 63 per cent.

The clinical presentation is variable (Table 2) 410 with many fibroids being symptomless and being found unexpectedly on a routine pelvic examination, e.g. while performing a cervical smear, or at laparotomy. While most symptoms lead to presentation to a gynaecologist, some will first present to a general surgeon and other specialties. Many patients complain of an abdominal swelling. In large fibroids pressure effects on the pelvic veins may result in, or exacerbate varicose veins and haemorrhoids. A large tumour filling the abdomen may cause dyspnoea. Pressure effects on the bladder or bladder neck may cause frequency of micturition and stress incontinence in the former and retention of urine in the latter. Irregular menstruation and infertility are also associated with fibroids. Pain, which may be acute and severe, may result from torsion of a pedunculated fibroid or that associated with red degeneration. Whether the pain is due to the fibroid or some other less obvious cause is often a diagnostic problem.

The main differential diagnosis is from ovarian tumours when as a rule, on vaginal examination, the uterus can be detected as separate from the swelling. However, if the ovarian tumour is adherent to the uterus difficulty arises. A pelvic ultrasound examination in most cases can delineate an ovarian from a uterine mass, although it is not unusual for the correct diagnosis to be reached only at laparotomy.

The incidental finding of fibroids (leiomyomas) at laparotomy should be noted and rarely is surgery indicated as an unplanned procedure in this situation. The only time when surgery would be considered is where a fibroid was pedunculated and had undergone torsion causing symptoms. This can be considered to be a true emergency procedure.

The main reason for performing a myomectomy (a local enucleation of the fibroid) is to improve fertility prospects for the management of menorrhagia exacerbated by fibroids in women who wish to retain their fertility potential, or to relieve pressure symptoms. The main complication during surgery is uncontrollable haemorrhage which can require hysterectomy and blood transfusion. However, it is rare that a hysterectomy has to be performed, although it is essential to counsel patients preoperatively. A current approach in these patients is to pretreat with gonadotrophin releasing hormones which reduces blood loss at surgery and the need for a hysterectomy. Hence, there is no place for emergency myomectomy by a general surgeon or a gynaecologist except in the instance mentioned above.

Gonadotrophin releasing hormone analogues are effective in shrinking fibroids and in reducing blood loss at myomectomy with large fibroids. This is now accepted practice before myomectomy for large fibroids. These analogues suppress ovarian function and can result in troublesome menopausal symptoms. Some of these can be controlled with norethisterone 5 mg daily.

Transcervical endoscopic resection or laser vaporization of submucous fibroids, after a preoperative course of suppressant analogues is being developed. These techniques are still in their infancy and results of trials are awaited.

Rupture of a myomectomy scar during pregnancy is rare. However, some obstetricians will opt for elective caesarean section at 38 weeks' gestation in patients who have had a previous myomectomy.

The standard treatment in a woman who has completed her family and who is usually aged over 35 years is a hysterectomy. In a woman under 45 years of age the problems involved in removal of both ovaries and subsequent hormone replacement therapy must be discussed before surgery. The rationale behind this is as follows: there is a 4 to 5 per cent risk of ovarian disease developing after hysterectomy and a 0.2 per cent (0.1–0.5 per cent) risk of developing ovarian cancer in the conserved ovaries; the function of the ovaries has declined significantly by this age, the average age of the menopause being 51 years in Europe.

Another application of suppressant analogues is to shrink a large fibroid sufficiently to allow a vaginal hysterectomy rather than an abdominal operation. Care must be taken in selecting these patients as there is a definite association of fibroids with endometriosis, which is a relative contraindication to vaginal hysterectomy.

In performing a myomectomy the surgeon must be careful to avoid damaging the fallopian tubes in their course through the myometrium. Incisions on the posterior uterine wall are to be avoided as far as possible because of the increased risk of adhesions involving the intestines, the ovaries, and the fallopian tubes. Adhesions involving the ovaries and fallopian tubes may hinder ovum pick-up. The ‘hood’ operation (as devised by Victor Bonney), in which the uterine incision is placed anteriorly over the fundus, is a useful method for removing posterior intramural fibroids so as to avoid this complication.

Long-term problems associated with performing a myomectomy are recurrence of fibroids necessitating subsequent surgery and uterine rupture during pregnancy.

Meticulous haemostasis during surgery is essential and to aid this a clamp (Bonney's clamp) can be placed at the level of the upper cervix temporarily to clamp the uterine vessels. A modification of this is to tie a Foley-type catheter around the upper cervix, having first fashioned a hole in the broad ligament on both sides. In conjunction with this method, the uterine blood supply coming from the ovarian artery can be interrupted medial to the ovary by using a rubber-shod Bainbridge-type vascular clamp.

The ureter is at risk of trauma during surgery, particularly with either a cervical or a broad ligament fibroid where vision can be limited. The course of the ureter can be very distorted or associated with endometriosis. The last process can lead to dense adhesions involving the bowel, greater omentum, peritoneum lining the pouch of Douglas, ovaries, and fallopian tubes.

With the tremendous advances in endoscopic equipment many centres are now performing both hysterectomies and myomectomies laparoscopically with obvious benefits to the patient. However, as these skills are exacting and the operations time consuming there is little if any role for the general surgeon in this area.

The incidence of fibroids in pregnancy varies between 0.5 and 5 per cent. Red degeneration of the fibroid can occur and give rise to acute abdominal pain, vomiting, low-grade pyrexia, exquisite localized peritoneal tenderness over the surface of the fibroid, and a marked leucocytosis.

The differential diagnosis includes many non-obstetrical causes of abdominal pain in the pregnant woman, of which the general surgeon should be aware. In attempting to arrive at a diagnosis Alder's sign may be of help in differentiating between pain and tenderness of genital and extragenital origin. The source of pain is located by palpation with the patient lying flat. She is then turned on her left side with the examining hand still in position. If the pain shifts to the left it is likely to originate in the uterus or adnexae but if there is no change the source is probably extragenital (e.g. appendicitis).

Unless there is serious doubt concerning the diagnosis the treatment is conservative with bed rest, sedation, and analgesia; resolution usually occurs in 4 to 7 days. Rarely, laparotomy may be required if the symptoms worsen and the possibility of an acute surgical condition such as appendicitis cannot be ruled out. A pedunculated fibroid may have undergone torsion and secondary degeneration and such a situation provides the sole indication for myomectomy during pregnancy. Fibroids should not be removed at caesarean section.

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