Uterine sacculation is a rare complication of pregnancy that occurs in about 1 in 3000 pregnancies1. It is defined as a sac-like structure that develops from an abnormal rotation of the uterine fundus2–4. Without diagnosis and treatment, this can cause spontaneous miscarriage, intrauterine fetal death, uterine rupture, preterm delivery, placenta accreta, retained placenta and postpartum hemorrhage5. However, this condition can easily be misdiagnosed as uterine septum on ultrasound examination. We describe a case of uterine sacculation in a pregnancy which was further complicated by the presence of a large uterine myoma.
A 28-year-old primigravida presented with vaginal leakage and urinary retention at 17 weeks' gestation. Her medical history was unremarkable except for a known uterine myoma. On physical examination, we were unable to visualize the cervix with a speculum but bulging membranes were seen. A nitrazine test showed a positive result, indicating rupture of membranes. On ultrasound examination the fetus was found to be in breech-oblique presentation with a normal heartbeat and of normal size. However, precise evaluation of the fetus was limited owing to severe oligohydramnios. Ultrasonography showed probable uterine folding and a huge mass measuring around 10 × 8 cm in the upper portion of the uterus (Figure 1a). The anterior wall of the uterus was thin and stretched, but the posterior wall was of normal thickness. Laboratory findings were unremarkable. The possibility of uterine sacculation was raised and magnetic resonance imaging (MRI) was performed for confirmation. Posterior sacculation of the uterus with a huge mass measuring around 11 × 8 cm was confirmed by sagittal T2-weighted images on MRI (Figure 1b). Figure 1c shows a schematic diagram of the findings.
A Foley catheter was inserted for urinary retention. Because of the premature rupture of membranes and early stage of gestation, termination of pregnancy was chosen. However, owing to extensive folding of the uterus and subsequent complete displacement of the cervix, vaginal delivery appeared impossible, therefore we decided to perform a hysterotomy. On entering the peritoneal cavity, a huge dumbbell-shaped mass measuring around 12 × 10 cm was seen (Figure 2). The uterus was severely distorted and the myoma appeared to consist of two fused masses, one of which was covered with tortuous and dilated vessels. Hysterotomy was performed and a grossly normal dead fetus weighing 160 g was delivered. Autopsy of the fetus was not carried out. Replacing the uterus back into the abdominal cavity was difficult owing to the large size of the myoma, so it was necessary to retrovert the uterus back into a state of uterine sacculation.
After the operation, the patient received four cycles of gonadotropin-releasing hormone agonist (leuprolide acetate depot, Lucrin®) and 6 months later she underwent myomectomy. Pathological examination confirmed leiomyoma of the uterus.
This case indicates that ultrasound examination may be sufficient in the diagnosis of uterine sacculation if the examiner has a correct understanding of this rare disease entity, although MRI is considered as the current imaging modality of choice for diagnosis and detailed evaluation6. When this condition is diagnosed in early pregnancy, pregnancy can be maintained conservatively with short-term follow-up in most cases. When conservative management is undertaken, it is important to prevent possible complications5. Therefore, it is necessary to advise the patient to report immediately any vaginal bleeding, vaginal leakage or low abdominal pain.