2022 年 10 巻 4 号 p. 125-128
This study aimed to present the diagnosis and management of adnexal masses of <6 cm in full-term pregnancy at a primary-level hospital. We present two cases of adnexal torsion. Cases 1 and 2 were conservatively managed for masses measuring 44.4×30.5 mm and 49.4×34.3 mm in the first trimester, and the patients experienced acute-onset serious abdominal pain at 39 and 37 weeks of gestation, respectively. Emergency cesarean section and unilateral salpingo-oophorectomy were performed. Histopathology confirmed serous cystadenoma with ischemic changes in both cases. Our findings suggest that clinical information regarding adnexal masses in the first trimester and their clinical symptoms can inform management decisions in the third trimester.
Adnexal torsion of <6 cm in the third trimester of pregnancy is low-risk and rare, but its preoperative diagnosis and management are challenging.1,2) Early and accurate diagnosis of the condition is crucial to avoid maternal and neonatal death. 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. Here, we present two cases of low-risk adnexal torsion in full-term pregnancy and discuss its diagnosis and management in the third trimester.
A 24-year-old Japanese woman was clinically diagnosed with spontaneous pregnancy. At 11 weeks of gestation, ultrasonography revealed the presence of a left adnexal mass measuring 44.4×30.5 mm with a simple cyst (Figure 1A). The size of the adnexal mass remained unchanged during the first trimester. She experienced a sudden onset of continuous pain in the left lower abdomen that lasted for 4 hours at 39+2 weeks of gestation. Maternal bilateral hydronephrosis was not identified by ultrasonography. Other symptoms, such as fever and vaginal bleeding, were not observed. Due to medical examinations scheduled during night hours, we were unable to examine her C-reactive protein (CRP) and urinary sediment levels. Cardiotocography (CTG) revealed a reassuring fetal status without uterine contraction. Considering the presence of an adnexal mass identified in the first trimester, adnexal torsion was suspected. However, abdominal ultrasonography could not detect the adnexal mass. Her Bishop score was 0. Owing to unbearable left lower abdominal pain, we performed an emergency cesarean section on the same day. Intraoperatively, the left adnexal mass was twisted at 360°, with signs of ischemia. Thus, left salpingo-oophorectomy was performed (Figure 1B). Histopathology confirmed serous cystadenoma with ischemic change.
Ultrasonographic images and ovarian cysts.
(A) Ultrasonography shows a left adnexal mass at 11 weeks of gestation in Case 1. (B) Photograph shows a left adnexal tumor (serous cystadenoma). (C) Ultrasonography shows a right adnexal mass with a bilocular ovarian cyst at 11 weeks of gestation in Case 2. (D) Photograph shows a right adnexal tumor (serous cystadenoma).
A 31-year-old Japanese woman was clinically diagnosed with spontaneous pregnancy. At 11 weeks of gestation, ultrasonography revealed the presence of a right adnexal mass measuring 49.4×34.3 mm with a bilocular ovarian cyst (Figure 1C). Given the lack of solid components in the cyst, we ruled out the possibility of malignancy. Prenatally, she was examined at our hospital. She presented at 37+2 weeks of gestation with continuous right abdominal pain that lasted for half a day, without nausea, vomiting, or vaginal bleeding. Abdominal ultrasonography revealed that the adnexal mass increased in size to 60.5×38.9 mm. In addition, the pain from the right adnexal mass was consistent. Maternal hydronephrosis was not identified by ultrasonography, and she had no fever or urinary symptoms. Due to medical examinations scheduled during night hours, we were unable to examine her CRP and urinary sediment levels. Her Bishop score was 1. CTG revealed a reassuring fetal status without uterine contraction. Given these clinical symptoms, adnexal torsion was suspected. Hence, an emergency cesarean section was performed on the same day. Intraoperatively, the right adnexal mass was twisted at 360° with congestion. Therefore, right salpingo-oophorectomy was performed (Figure 1D). We did not observe an appendix with abscess, and histopathology confirmed a serous cystadenoma with ischemic change.
Adnexal torsion of <6 cm in the third trimester is very rare, and its diagnosis and management are challenging.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 the two cases presented, ultrasonography in the first trimester detected a unilateral adnexal mass of <6 cm without solid components. 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. We conservatively managed both patients after excluding the possibility of malignancy by ultrasonography. Both patients experienced sudden-onset and continuous pain without uterine contraction. However, neither patient exhibited fever or urinary symptoms and hydronephrosis was not identified by ultrasonography. Therefore, we ruled out the possibility of urinary infection, although we could not confirm CRP and urinary sediment levels due to medical examinations scheduled during night hours. In Case 2, we confirmed the condition of the appendix during the operation. After excluding urinary infection, urolithiasis, and placental abruption, and considering the clinical information obtained in the first trimester, we suspected adnexal torsion. Unfortunately, we could not perform pelvic MRI in our primary-level hospital to confirm this. Bishop scores in Case 1 and Case 2 were 0 and 1, respectively, leading us to perform cesarean section. For full-term pregnancy, clinical information regarding adnexal masses obtained in the first trimester is important when considering the possibility of adnexal torsion in primary-level hospitals. However, pregnant women who have adnexal masses earlier than 36 weeks of gestation must be referred to a perinatal medical center for neonatal management.
We searched for associations between adnexal mass, torsion, term pregnancy, and primary-level hospital in the PubMed database (https://www.ncbi.nlm.nih.gov/pubmed/). To the best of our knowledge, there are no reports on the management of low-risk adnexal torsion in full-term pregnancy at primary-level hospitals. Although a report by the American College of Obstetricians and Gynecologists suggests that adnexal masses in pregnancy have a low-risk of malignancy and acute complications and that they may be managed expectantly, there is no recommendation regarding the mode of delivery at primary-level hospitals for such cases.10) The two cases presented here suggest that cesarean section should be considered a mode of delivery at primary-level hospitals if adnexal torsion is suspected during pregnancy. Our findings are novel in that they demonstrate that both the size of the adnexal mass in the first trimester and clinical symptoms are useful for informing treatment decisions in full-term pregnancies at primary-level hospitals. Retrospectively, it was found that the adnexal mass in Case 2 had increased in size, and that the adnexal mass in Case 1 could not be detected by ultrasonography. Such changes in the adnexal mass may be helpful for diagnosing adnexal torsion.
In conclusion, when a low-risk adnexal mass was expectantly managed during pregnancy in a primary-level hospital, both clinical information regarding the adnexal mass obtained in the first trimester and its clinical symptoms were useful for informing treatment decisions in the third trimester.
We thank the patients and their families for particiapting in this study. We also thank Enago (https://www.enago.jp/) for editing a draft of this manuscript.
The authors declare that they have no conflict of interest.
T.S. designed the study and wrote the manuscript; H.D., N.Y., and T.H. managed and operated on the two cases; T.H. drafted and critically revised the manuscript.
