Degenerating Fibroid

A degenerating fibroid is a fibroid whose blood supply is outgrown or interrupted, so that tissue changes occur inside it: hyaline, cystic, calcific, myxoid, red (carneous) or necrotic degeneration.

• It occurs in large fibroids, in pregnancy, after embolisation and in the postpartum period.
• Hyaline change is the most common and is usually silent.
• Acute pain is the main symptom of red and necrotic degeneration.

Sudden pelvic or abdominal pain over the fibroid, low-grade fever, nausea, vomiting and localised tenderness of the uterus.

• A tender, firm uterine mass; mild leucocytosis.
• Differential diagnosis: fibroid torsion, ovarian torsion, ectopic pregnancy, appendicitis, pelvic inflammatory disease, leiomyosarcoma, placental abruption in pregnancy.
• Complications: infection and sepsis of a necrotic fibroid, peritonitis, preterm labour in pregnancy, anaemia, and calcified fibroid in elderly women.

Diagnosis is clinical, supported by ultrasound, after exclusion of other causes of acute pain.

• Examination for focal tenderness over the fibroid.
• Ultrasound showing a heterogeneous or cystic fibroid with absent flow on Doppler; MRI where available.
• Full blood count; C-reactive protein; pregnancy test; urinalysis; blood culture if febrile above 38 degrees Celsius.
• Exclude other causes of acute abdominal pain.

Treat with rest and analgesia, and operate only for sepsis, suspected sarcoma or pain that does not settle.

• Supportive: bed rest, oral or IV fluids, heat to the abdomen, observation of temperature and vital signs for 48 hours.
• Pharmacological: ibuprofen 400 mg oral 8-hourly with food (maximum 1.2 g in 24 hours) and paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours) for 3 to 7 days. Severe pain: morphine 2.5 to 5 mg IV titrated every 5 minutes, or tramadol 50 to 100 mg oral 6-hourly (maximum 400 mg in 24 hours). Infected or necrotic fibroid: ceftriaxone 1 g IV daily plus metronidazole 500 mg IV 8-hourly until afebrile for 24 hours, then amoxicillin-clavulanate 625 mg oral 8-hourly to complete 7 to 10 days.
• Procedures: myomectomy or hysterectomy for pain that does not settle in 7 days, sepsis or suspected sarcoma; uterine artery embolisation in selected women.
• Special groups: in pregnancy use paracetamol and morphine, avoid ibuprofen from 28 weeks, give hydration and check for preterm labour. In renal impairment avoid ibuprofen.
• Red flags: persistent fever, peritonism, shock, fast growth, postmenopausal pain.
• Follow-up: review at 1 week and 6 weeks; repeat ultrasound at 3 months.