Intramural Fibroid

An intramural fibroid is a smooth muscle tumour inside the myometrium of the uterine wall. It is the commonest fibroid type.

• It enlarges the uterus and may distort the cavity.
• It causes bleeding, pressure and pain, but many are silent.
• Growth depends on oestrogen and progesterone, so it usually shrinks after menopause.

Heavy menstrual bleeding, dysmenorrhoea, pelvic pressure, urinary frequency, constipation, abdominal enlargement, dyspareunia and infertility; many women have no symptoms.

• An enlarged firm irregular uterus on bimanual examination.
• Differential diagnosis: adenomyosis, subserosal and submucosal fibroids, ovarian mass, leiomyosarcoma, pregnancy, endometrial hyperplasia.
• Complications: anaemia, infertility, miscarriage, preterm labour, malpresentation, obstructed labour, postpartum haemorrhage, red degeneration and rarely sarcoma.

Diagnosis is by ultrasound, with MRI for multiple or large fibroids.

• Transvaginal and abdominal ultrasound.
• Pelvic MRI to map multiple or large fibroids or to differentiate from adenomyosis and sarcoma.
• Full blood count and ferritin; pregnancy test; renal ultrasound for large fibroids.
• Endometrial sampling in women aged 45 or over with abnormal bleeding.
• Histology after surgery.

Observe asymptomatic fibroids, control bleeding medically, and operate for symptoms or fertility needs.

• Supportive: observe asymptomatic fibroids with ultrasound every 6 to 12 months; menstrual diary; counselling on fertility.
• Pharmacological: tranexamic acid 1 g oral 8-hourly for up to 4 days during heavy bleeding (maximum 4 g in 24 hours; reduce the dose in renal impairment; avoid in thromboembolism). Mefenamic acid 500 mg oral 8-hourly with food during menses or ibuprofen 400 mg oral 8-hourly with food (maximum 1.2 g in 24 hours). Levonorgestrel 52 mg intrauterine system when the cavity is not distorted. Leuprorelin 3.75 mg IM every 4 weeks for up to 3 months before surgery. Anaemia: ferrous sulphate 200 mg oral 8-hourly, continued for 3 months after haemoglobin normalises; iron sucrose 200 mg IV per dose for severe anaemia.
• Procedures: laparoscopic or open myomectomy for women who want to keep fertility; hysterectomy when fertility is complete; uterine artery embolisation in selected women; transfuse when haemoglobin is below 7 g/dL or there is active bleeding with shock.
• Special groups: in pregnancy give paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) for pain and avoid ibuprofen from 28 weeks; red degeneration is managed with rest, hydration and analgesia. After myomectomy that opened the cavity or went through more than half the wall, deliver by caesarean at 37 to 38 weeks.
• Red flags: rapid growth, postmenopausal growth, haemoglobin below 7 g/dL, sudden severe pain with fever, urinary retention.
• Follow-up: review at 6 weeks and 3 months after treatment; ultrasound at 6 to 12 months if observed.