Torsion of a paraovarian cyst on the fallopian tube: Case report.

A 28-year-old woman presented to the emergency department with acute-onset severe lower abdominal pain localized to the right iliac fossa. The pain was associated with nausea and vomiting but without fever. She reported her last menstrual period was 10 days prior, was nulliparous, and had no significant medical or surgical history, including no prior gynecological conditions, pelvic infections, or use of intrauterine devices. Her menstrual cycles were regular, with no recent changes. On clinical examination, she exhibited tenderness in the right lower quadrant with signs of peritoneal irritation. Pelvic examination revealed a tender, mobile mass in the right adnexa without cervical motion tenderness or abnormal discharge. The uterus and left adnexa were unremarkable on palpation. Transvaginal ultrasound revealed a 5.2 × 4.8 cm right adnexal cyst with thickened walls (3 mm), a heterogeneous echotexture, and no internal septations or solid components. Doppler imaging showed diminished vascularity to the cyst and adjacent fallopian tube, with a “whirlpool sign” suggestive of a twisted vascular pedicle. The right ovary appeared normal in size (3.0 × 2.5 cm) with preserved blood flow. The uterus was normal (7.5 × 4.0 cm), and a small amount of free fluid was noted in the cul-de-sac. The left adnexa was unremarkable. Laboratory investigations included a white blood cell count of 12,000/μL (mildly elevated), C-reactive protein of 25 mg/L (elevated), and a negative urine pregnancy test, ruling out ectopic pregnancy. Serum CA-125 was within normal limits (20 U/mL), reducing suspicion of malignancy. Given the acute presentation and the high suspicion of adnexal torsion, the patient was taken for emergency laparoscopy after differential diagnoses, including appendicitis, ovarian torsion, and ruptured ovarian cyst, were considered. • Intraoperative Findings Intraoperative Findings Laparoscopic exploration revealed a twisted paraovarian cyst on the right fallopian tube, leading to complete necrosis of both the cyst and the fallopian tube. The affected structures appeared dark and ischemic, confirming the diagnosis of adnexal torsion with irreversible tissue damage. The right ovary was normal in appearance and position, with no signs of torsion or ischemia. The uterus and left adnexa, including the left fallopian tube and ovary, were inspected and found to be structurally normal, with no evidence of cysts, adhesions, or abnormal masses ( Fig. 1 , Fig. 2 , Fig. 3 , Fig. 4 ). Fig. 1 Three twists of the cyst around the fallopian tube. Fig. 1 Fig. 2 Paraovarian cyst post-detorsion. Fig. 2 Fig. 3 Laparoscopic view of the paraovarian cyst. Fig. 3 Fig. 4 Excised necrotic paraovarian cyst and fallopian tube. Fig. 4 Three twists of the cyst around the fallopian tube. Paraovarian cyst post-detorsion. Laparoscopic view of the paraovarian cyst. Excised necrotic paraovarian cyst and fallopian tube. In Fig. 1 , the image illustrates the mechanism of torsion, where the paraovarian cyst has rotated three times around the right fallopian tube. The constriction has led to vascular compromise, resulting in ischemia. The uterus is visible in the background, and the right ovary is identifiable, appearing unaffected. In Fig. 2 , following the release of the torsion, the ischemic changes of the cyst and fallopian tube are evident. The dark discoloration suggests complete loss of vascular supply, confirming necrosis. The right ovary remains visible and unaffected. Fig. 3 shows the initial intraoperative findings, where the uterus, right fallopian tube, and paraovarian cyst are clearly identified. The right ovary is visible adjacent to the torsed structures, with normal coloration, and the left adnexa appears normal in the background. Fig. 4 shows the resected specimen, demonstrating the completely necrotic paraovarian cyst and fallopian tube, confirming the intraoperative findings. Given the extent of necrosis, a right salpingectomy was performed, and the necrotic paraovarian cyst was completely excised. The procedure was uneventful, and hemostasis was achieved. The patient had an uneventful postoperative recovery and was discharged on the second postoperative day with appropriate analgesia and antibiotics. Histopathological examination of the excised specimen confirmed the diagnosis of a necrotic paraovarian cyst with ischemic changes in the fallopian tube. At the one-month follow-up, the patient reported complete resolution of symptoms, and no complications were observed. A follow-up transvaginal ultrasound confirmed a normal uterus, right ovary, and left adnexa, with no evidence of new cysts or abnormalities, supporting future fertility potential through the left fallopian tube.

Montacer Hafsi: conception and design, acquisition of data drafting the article, revising it critically for important intellectual content final approval of the version to be published Houssem Ragmoun: conception and design, acquisition of data drafting the article, revising it critically for important intellectual content final approval of the version to be published Eya Kristou: final approval of the version to be published Bezzine Meriem: final approval of the version to be published Amina Abaab: final approval of the version to be published Sarra Rihani: final approval of the version to be published

Written informed consent was obtained from the patient for publication of this case report and any accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal.

Ethical approval was not required for this case report as it was deemed not to constitute research involving human subjects under the policies of our institution. The report is based on a retrospective review of a single clinical case, and no experimental intervention was performed. According to Ethics Committee at Menzel Temim Hospital, case reports involving fewer than three patients do not require IRB approval. Therefore, this case was exempt from ethics approval.

Not applicable. All authors read and approved the final manuscript.

None.

The corresponding author is the guarantor of submission.

This case highlights the importance of considering paraovarian cyst torsion in women presenting with acute pelvic pain. Early recognition and timely laparoscopic intervention can prevent complications and ensure optimal patient outcomes. While rare, the possibility of complete fallopian tube necrosis underscores the necessity for prompt surgical management and careful evaluation of contralateral structures to support future fertility.

Paraovarian cysts originate from embryologic remnants of the paramesonephric (Müllerian) or mesonephric (Wolffian) ducts within the mesosalpinx or broad ligament, distinguishing them from ovarian cysts, which arise from ovarian follicles or corpora lutea. These cysts are typically unilateral, thin-walled, and filled with serous fluid, ranging from 1 to 8 cm in size. Unlike ovarian cysts, paraovarian cysts are less likely to be hormonally responsive, reducing their association with menstrual cycle changes. Risk factors for their development are poorly defined, but associations with pelvic inflammatory disease, endometriosis, or previous pelvic surgery have been suggested, though none were present in our patient. The prevalence of paraovarian cysts is estimated at 2–3 % of adnexal masses, with torsion occurring in less than 1 % of cases, making this presentation exceptionally rare [ 1 , 2 ]. Paraovarian cyst torsion is a rare but significant gynecological emergency that often presents with acute abdominal pain, making it challenging to differentiate from other conditions such as ovarian torsion, appendicitis, or ectopic pregnancy [ 3 ]. The clinical profile typically includes sudden-onset unilateral pelvic pain, nausea, and vomiting, as seen in our patient. Peritoneal signs, as niche, suggest advanced ischemia or necrosis. Unlike ovarian torsion, which may involve cyclic pain related to ovarian enlargement, paraovarian cyst torsion often presents with constant pain due to its non-hormonal etiology. The lack of fever in our case helped differentiate it from infectious causes like appendicitis or pelvic inflammatory disease [ 4 ]. The distinction between ovarian and paraovarian cysts is critical for management. Ovarian cysts are more common (approximately 90 % of adnexal masses), often functional, oscopic surgery has emerged as the gold standard for both diagnosis and treatment, offering several advantages over open surgery, including reduced postoperative pain, shorter hospital stays, and faster recovery times [ 5 ]. Compared to laparotomy, laparoscopy minimizes adhesion formation (5–10 % vs. 20–30 %), reduces blood loss (50–100 mL vs. 200–500 mL), and shortens hospital stays (1–2 days vs. 4–7 days), making it ideal for young patients like ours. Laparotomy may be required for complex cases with extensive necrosis or malignancy concerns, but no such indications were present here [ 6 , 7 ]. During laparoscopic surgery, detorsion of the twisted cyst can be attempted if there is no evidence of necrosis. However, if necrosis is present, excision of the cyst and, in some cases, the affected fallopian tube may be required [ 8 ]. The preservation of ovarian tissue is a priority, especially in women of reproductive age, to maintain fertility and hormonal function [ 9 ]. In our case, the right ovary was preserved, and the left fallopian tube was confirmed to be intact, supporting future fertility. Salpingectomy was necessary due to complete necrosis, but unilateral tubal loss does not significantly impair fertility, as ovulation from either ovary can utilize the remaining tube [ 10 ]. Postoperative outcomes are generally favorable, with most patients experiencing complete resolution of symptoms and minimal risk of recurrence [ 11 ]. In conclusion, paraovarian cyst torsion, though rare, requires a high index of suspicion and prompt management to prevent severe complications. Imaging plays a critical role in diagnosis, while laparoscopic surgery remains the preferred approach for both confirming the diagnosis and providing effective treatment. Early intervention is key to preserving fertility and ensuring optimal patient outcomes [ 12 ].

Paraovarian cysts are benign adnexal cysts originating from the mesosalpinx or broad ligament, accounting for approximately 2–3 % of adnexal masses. While most remain asymptomatic, they can significantly affect quality of life when complications such as torsion, hemorrhage, or rupture occur. Torsion of a paraovarian cyst, particularly involving the fallopian tube, is a rare gynecological emergency with an estimated incidence of less than 1 % among women with adnexal pathology. This condition can lead to ischemia, necrosis, and potentially life-threatening complications like peritonitis if untreated. The nonspecific presentation of acute pelvic pain often mimics other conditions, such as ovarian torsion, appendicitis, or ectopic pregnancy, posing diagnostic challenges. Prompt recognition and surgical intervention are critical to prevent irreversible damage to reproductive structures, particularly in women of reproductive age where fertility preservation is a priority. This case report, prepared in accordance with the SCARE 2023 guidelines for surgical case reports, presents a rare instance of paraovarian cyst torsion leading to complete necrosis of the cyst and fallopian tube, highlighting its clinical and surgical management [ 1 ].

All authors declare that they have no conflicts of interest.