Torsion of Large Subserous Uterine Fibroid in a Postmenopausal Woman

Introduction Uterine fibroids or leiomyomas are benign, smooth-muscle growth and are the most common gynaecologic tumours, found in 60% of women in their reproductive period. However, they rarely become symptomatic after menopause.

Uncomplicated fibroids can be asymptomatic, but when symptomatic they may result in pain abdomen, heavy menstrual bleeding, dysmenorrhoea, backache, pressure symptoms on bowel and bladder, infertility. Severe complications include torsion of the fibroid, intraperitoneal haemorrhage, prolapse of submucosal fibroids, acute urinary retention and venous thrombosis. Although the prevalence of fibroids is high, acute complications are quite rare. But when they do occur, failure to identify and deal with these acute complications expeditiously can lead to catastrophic outcomes.

Torsion of a pedunculated fibroid is rare cause of acute abdomen with an incidence of less than 0.25%. It is considered as an acute surgical emergency due to the high risk of ischaemic gangrene and associated peritonitis. It is usually diagnosed intraoperatively because the imaging findings are non-specific and can mimic with the symptoms of more commonly encountered leiomyoma degeneration, thus making the pre-operative diagnosis difficult.

This case report describes a case of a torsed, pedunculated, subserosal uterine leiomyoma.

Case report

We report a rare case of uterine fibroid torsion in a 67 year old postmenopausal woman. The patient presented to us with pain abdomen on and off which increased since one week. On physical examination, the patient’s abdomen was distended with a firm and tender pelvic mass reaching above the umbilicus. The patient’s vitals were stable and laboratory investigations were within normal limits. A transabdominal ultrasound (US) of the pelvis was performed which showed a large, well-circumscribed, heterogeneous, hypoechoic, solid abdomino-pelvic mass, measuring 16cm x 16 cm x 12 cm.

Pelvic magnetic resonance imaging also suggested a large pedunculated uterine fibroid 20.5x 19.8×13.2 cm with cystic degeneration changes (Type 7) and confirmed bilateral intact ovaries, excluding the possibility of ovarian torsion. Intraoperative examination confirmed the diagnosis of pedunculated subserous uterine fibroid twisted by 360°. Detorsion was done and proceeded with hysterectomy.

Discussion

If left untreated, the torsion could have led to fibroid necrosis and autoamputation, resulting in morbidity. Misdiagnosing torsions with the more common fibroid degeneration can lead to fatal complications. In cases of inconclusive ultrasound findings, MRI is performed for its higher sensitivity and specificity. The pedicle of a subserosal leiomyoma is better appreciated on MRI and the mass indicating the ‘bridging vessel sign’, which suggests uterine origin of the mass and thereby differentiating it from an adnexal mass. In this case, the attachment site of the pedicle with the uterus was well appreciated on MRI. It is also important to identify normal ovaries separate from the mass.It is a challenging situation when patient presents with acute pain abdomen.

Thus, the possibility of uterine fibroid torsion should always be considered even after menopause and timely surgical intervention should be provided. The presentation is variable depending on the speed at which the torsion develops. If the torsion is partial with spontaneous untwisting, symptoms may be intermittent or even resolve spontaneously. Complete torsion results in circulatory venous stasis and congestion followed by arterial compression resulting in haemorrhagic necrosis and gangrene leading to excruciating pain If untreated, haemorrhagic infarction of the torsed fibroid can lead to infection and peritonitis. Torsed uterine fibroids can be managed surgically by myomectomy or hysterectomy depending on the age and desired fertility of the patient.

Conclusion

While intraoperative findings remains the mainstay of diagnosis, radiologists should be familiar with the potential imaging findings of leiomyoma torsion as a proper and timely intervention can greatly improve patient outcome and avoid morbidity to the patient. It is also important to recognise the need for prompt exploratory surgery in any patient presenting with acute abdominal pain and the clinical suspicion of torsion.