A case of torsion of a normal ovary in the third trimester of pregnancy: MRI findings with emphasis on asymmetry in the diameter of the ovarian veins

Abstract

A 33-year-old woman, gravida two para one, at 31 weeks of gestational age experienced sudden onset of left lower quadrant pain and underwent unenhanced pelvic MRI. On fast imaging employing steady state precession (FIESTA) sequence images, a marked difference was observed in the diameters of the right and left ovarian veins. The right ovarian vein was torturous and dilated, measuring 35 mm in diameter, while the left ovarian vein was thin and linear, measuring 7 mm in diameter. The left ovary showed no apparent swelling or hemorrhage, but was suspected to have been shifted anteriorly. The patient underwent explorative laparotomy and was found to have left ovarian torsion. A difference in diameter of the ovarian veins, with thinning of the twisted side and compensatory dilatation of the contralateral side for drainage of increased uterine blood flow, may be a useful imaging sign for the diagnosis of ovarian torsion during pregnancy.

Gasless laparoendoscopic single-site assisted extracorporeal ovarian cystectomy through the umbilicus for the management of ovarian torsion at 33 weeks of gestation: A case report with literature review

“…Adnexal masses of 6–8 cm are more prone to torsion than are masses of other sizes [ 12 , 13 ]. Furthermore, pregnancy is one of the potential risk factors for adnexal torsion [ 14 ], which is most frequently seen in the first and early second trimesters.…”

“…One of the main reasons for the increase in adnexal torsion in early gestation is the presence of a corpus luteum cyst, which tends to torsion, or otherwise spontaneously regresses as the pregnancy progresses into the second trimester [ [12] , [13] , [14] ]. Therefore, decisions regarding expectant or surgical management of adnexal masses, especially those discovered in early pregnancy, should be balanced by the risk of torsion, the likelihood of spontaneous resolution, concerns about malignancy, and the risk of surgery [ [12] , [13] , [14] ]. Accordingly, careful observation was chosen in the current case, early in gestation, since the bilateral cystic adnexal masses were small and asymptomatic.…”

Two cases of low-risk adnexal torsion in the third trimester of pregnancy

“…1,2) In the case of adnexal masses measuring < 6 cm in the third trimester, ultrasonography may not be sufficient to assess pelvic pain due to the enlarged uterus, alhtough it can be suitable for other cases of acute pelvic pain. 1,2,5) While MRI is effective for detecting adnexal mass torsion in the third trimester, 3,4) it cannot be performed in a primary-level hospital. Early diagnosis of adnexal torsion is important to prevent perinatal death.…”

“…In most cystic lesions measuring < 6 cm, expectant management is generally recommended. [3][4][5][6][7][8] Tumor markers, such as cancer antigen 125, beta-human chorionic gonadotropin, and alpha-fetoprotein, do not help differentiate between benign and malignant masses during pregnancy. 5,9) Therefore, we did not investigate these tumor markers.…”

“…In the third trimester, magnetic resonance imaging (MRI) is useful for diagnosing adnexal torsion. 3,4) However, MRI is usually unavailable in primary-level hospitals, including our hospital. For full-term pregnancy cases in particular, it is important to determine whether surgical intervention or transport to a tertiary emergency medical facility is required.…”