Uterine torsion with necrosis of bilateral adnexa in a postmenopausal woman

Abstract

Uterine torsion is an uncommon entity that is defined as a rotation of greater than 45° around the longitudinal axis of the uterus. Although cases of uterine torsion among pregnant patients have been mentioned in the literature, torsion of a non-gravid uterus is a rare occurrence. A 73-year-old nulliparous woman with a known fibroid uterus underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy with frozen section of a 17–18 cm pelvic mass seen on CT imaging. The source of the pelvic mass was unclear on imaging, and benign and malignant possibilities were discussed. During the procedure, necrosis of the uterine fundus and bilateral adnexa were seen due to the fundus being torsed with the uterine fibroid being the pivot point. Uterine torsion, though rare, can be the cause of acute pelvic pain in a postmenopausal woman.

Background

Uterine torsion is a rare entity defined as a rotation of greater than 45° around the longitudinal axis of the uterus.^{1 2} Risk factors include fibroids, ovarian tumours, mullerian anomalies, pelvic adhesions and abdominal/ligamentous laxity generally seen during pregnancy. Presenting symptoms include abdominal pain and/or pressure, nausea, vomiting, gastrointestinal and urinary complaints. A 180° dextrorotation is the most common presentation encountered surgically in this condition. Diagnosis of uterine torsion is difficult as patients are generally asymptomatic and only present with signs and symptoms of an acute abdomen when gradual uterine torsion results in necrosis.² Cases of torsion of the uterus have been known to occur more commonly during pregnancy.¹ Gravid uteri with torsion diagnosed at time of caesarean section have presented with obstructed labour, fetal malpresentation, vaginal bleeding, symptoms of acute abdomen and fetal compromise. The few cases of non-pregnant women with torsion were diagnosed at time of surgical evaluation to rule out malignancy in a pelvic mass.

Case presentation

We present a 73-year-old nulliparous woman with a 20-year history of a fibroid uterus who presents for further evaluation and management of her chronic, dull abdominal pain secondary to her fibroids. Two weeks prior to her office visit, the patient was seen in the emergency room at another facility due to sharp, right lower quadrant pain radiating to her back. During that visit, the patient was ruled out for an appendicitis and discharged for outpatient follow-up of a large pelvic mass. In addition, the patient reported acute worsening of her pelvic pain and pressure especially noted with positional changes. The patient stated she received some pain relief with narcotics and lying down. The patient denied symptoms of fever, chills, dysuria, change in bowel habits, weight gain or weight loss, early satiety, increasing abdominal girth or postmenopausal bleeding.

On physical examination in the office, the patient had mild tenderness to palpation in the left and right lower quadrant of the abdomen. However, she did not have signs concerning for an acute abdomen. There was no guarding or rebound tenderness on palpation. Pelvic examination demonstrated a smooth, firm, mobile mass in the lower abdomen extending to the umbilicus. The uterus and adnexa could not be distinguished from this mass.

Investigations

Transvaginal ultrasound revealed a 17 cm anterior uterine fibroid and a 7.9 cm left adnexal or uterine mass-like structure in the posterior pelvic regions that lacked blood supply. CT imaging confirmed a heterogeneous mass in the pelvis of uterine or ovarian origin measuring 18× 12.5×14 cm, with surrounding ascites and a twist in the lower uterine segment concerning for a possible uterine torsion (figures 1 and 2). Given the inability to determine the benign or malignant nature of the mass based on imaging, the patient was counselled on her options, and she elected for surgical management. She underwent a total abdominal hysterotomy with bilateral salpingo-oophorectomy (BSO).

Figure 1.

Coronal CT of the abdomen and pelvis indicating the pivot point where the uterine torsion occurred. The point of the solid arrow delignates the torsion.

Figure 2.

Sagittal CT of the abdomen and pelvis demonstrating pelvic mass, indistinguishable from uterus and adnexa.

Treatment

On entry into the abdomen, blood-tinged fluid was noted in the peritoneal cavity and was sent for cytological evaluation, which was negative for malignant cells. A haemorrhagic necrotic mass arising from the posterior aspect of the uterus was seen (figure 3). Frozen section revealed the mass to be a benign fibroid. On further examination, the uterus appeared to be torsed on the cervix with a large posterior fibroid, approximately 16 cm, being the pivot point (figure 4). The fibroid also appeared to be torsed twice. Due to the uterine torsion, both ovaries and fallopian tubes were necrotic. The uterus was carefully removed and sent for frozen section, which was consistent with haemorrhage and necrosis and no evidence of malignancy. BSO was done separately (figure 5) because of significant peritoneal thickening causing distortion in anatomy. Bilateral ureters were not able to be immediately identified even with the opening of the retroperitoneal spaces. The gangrenous nature of the pelvic organs also created difficulties in grasping the tissues. The patient tolerated the procedure well and experienced no complications intraoperatively or postoperatively.

Figure 3.

Gross image of a necrotic mass arising from the posterior aspect of the uterus, likely a posterior fibroid.

Figure 4.

Gross image of the uterus corpus showing torsion point.

Figure 5.

Gross image of necrosis of left ovary and left fallopian tube.

Outcome and follow-up

Final pathology of the specimens revealed a hyalinised subserosal leiomyoma and uterus with organising thrombus and haemorrhage. Bilateral ovaries and fallopian tubes had haemorrhage, infarction and focal calcifications. The patient is alive and well after being over 1 year postoperative status.

Discussion

Torsion of the ovary, fallopian tube or both is an established complication associated with benign and malignant tumours in postmenopausal women.^{1 2} Although a rare entity, uterine torsion is a source of acute abdomen in approximately 3% of premenopausal and postmenopausal patients presenting with abdominal pain. Uterine torsion is generally noted in gravid uteri, as the relaxation of pelvic structure and laxity in pregnancy make it easier for the gravid uterus to torse. However, enlarged fibroids are the most common predisposing factor associated with uterine torsion in non-pregnant women as the weight of the fibroid creates an asymmetric weight distribution.^{2 3} Generally, fibroids are known to regress, especially in postmenopausal women, due to the decrease in circulating oestrogen. Despite our patient’s postmenopausal symptoms, the size and weight of this patient’s fibroid caused traction and is theorised to have gradually caused the uterus to torse.

On review of the literature, the initial presentation often differs. Most patients will present with acute onset of abdominal pain; however, there has been one report of a patient who presented with painless gradual abdominal distention.² Our patient’s symptomatology differs in that she had chronic abdominal pain, which she attributed to her large fibroid. However, given the necrosis of the patient’s adnexa bilaterally, the patient’s uterine torsion may have existed for a prolonged time. The ascites noted was likely reactive from chronic inflammation. The presence of peritoneal and acute signs varies case by case even though necrosis has been often found on laparotomy.

Given the rarity of uterine torsion, it has been noted that the pivot point is usually located at the isthmus of the uterus. CT imaging usually denotes an ‘X’ shape. Diagnosis of uterine torsion is difficult with ultrasound alone. Suspicion for uterine torsion is usually seen when comparing previous ultrasounds and observing changes in anatomic location of pelvic structures.^4–6 Our patient, unfortunately, did not have a prior ultrasound for comparison, and CT imaging plus laparotomy were used for diagnosis. Although there is little literature regarding uterine torsion in postmenopausal women, unrecognised torsion and delay of surgical therapy can lead to complications such as haemorrhage, sepsis and coagulopathy.

Patient’s perspective.

I have been postoperative 1.5 years, and I am entirely grateful for what the team had done for me. It goes to show that the surgery was a success and I can definitely say that my quality of life has significantly improved. I sure hope that my case, being a rare one, will be able to help other doctors when considering an unusual diagnosis.

Learning points.

• Differential diagnosis of a pelvic mass in a postmenopausal woman should include uterine torsion even though it is rare.

• Sequelae of a fibroid uterus can occur many years after menopause.

• Although there is a risk of additional radiation, CT imaging provides more substantial evidence to indicate uterine torsion rather than ultrasound.