Single-port laparoscopic management of acute omental cyst torsion initially misdiagnosed as adnexal torsion: a first report and diagnostic lessons learned

Introduction

Adnexal torsion represents a critical gynecologic emergency, primarily affecting women of reproductive age. Prompt surgical intervention is essential to salvage the adnexa and preserve fertility (1,2). Despite advancements in imaging techniques such as ultrasound and computed tomography (CT)/magnetic resonance imaging (MRI), preoperative differentiation from other acute abdominopelvic pathologies remains challenging due to frequently nonspecific clinical and radiological presentations (2,3). Consequently, current guidelines strongly advocate for emergency diagnostic laparoscopy in cases of suspected adnexal torsion to facilitate timely detorsion and organ preservation (1-3).

Among the conditions mimicking adnexal torsion, acute torsion of an omental cyst presents a rare but significant diagnostic pitfall. Omental cysts are uncommon, typically benign intra-abdominal lesions. While often asymptomatic, they can manifest acutely due to complications like torsion, rupture, or hemorrhage. When torsion occurs, the clinical manifestations, characterized by acute lower abdominal pain, tenderness, and the presence of a cystic mass on imaging, can be indistinguishable from those of ovarian or adnexal torsion (4). This diagnostic overlap may lead to preoperative misdiagnosis and potential delays in appropriate management.

Herein, we present a compelling case of acute omental cyst torsion initially misdiagnosed as adnexal torsion based on clinical and radiological findings. This case underscores the diagnostic challenges inherent in distinguishing these entities preoperatively and highlights the pivotal role of laparoscopy, particularly the minimally invasive single-port approach, in achieving both definitive diagnosis and therapeutic resolution. Furthermore, this report aims to reinforce the importance of including omental cyst torsion in the differential diagnosis of women presenting with acute lower abdominal pain and a suspected adnexal mass.

Case presentation

All procedures performed in this study were in accordance with the ethical standards of the ethics committee and the data inspectorate of West China Second University Hospital of Sichuan University (No. 460) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

A 27-year-old nulliparous woman presented to the emergency department with acute-onset lower abdominal pain persisting for 24 hours. She denied nausea, vomiting, vaginal bleeding, or pregnancy. Her medical and surgical histories were unremarkable. On admission, vital signs were stable. Physical examination revealed localized deep tenderness in the right lower quadrant (3 cm lateral to McBurney’s point), without rebound tenderness or guarding. Transvaginal ultrasound showed a large unilocular, thin-walled cystic mass (measuring approximately 8.0 cm × 3.9 cm) that was contiguous with the right adnexa and had obscured margins with the ipsilateral ovary. The absence of internal vascularity raised suspicion for torsion (Figure 1A). Contrast-enhanced CT demonstrated a large hypodense cystic lesion (measuring approximately 7.8 cm × 3.8 cm) adjacent to the right adnexa. Critical findings included a mass effect obscuring the right ovarian borders, absence of both fat density and solid components, and no clear anatomical separation from pelvic structures (Figure 1B). Laboratory parameters, including white blood cell count, C-reactive protein, and relevant tumor markers (e.g., CA-125, CEA, CA 19-9), were within normal ranges.

Figure 1 Transvaginal ultrasound and contrast-enhanced CT images of the patient with omental cyst torsion. Transvaginal ultrasound demonstrated a unilocular, thin-walled cystic mass measuring approximately 8.0 cm × 3.9 cm in the right adnexa with absent internal vascularity (A). Contrast-enhanced CT confirmed a hypodense cystic lesion measuring approximately 7.8 cm × 3.8 cm in the right adnexal region, showing no solid components or fat density (B). CT, computed tomography.

Based on a provisional diagnosis of ovarian cyst torsion, emergency single-port laparoscopy was performed via a 2.5-cm transumbilical incision. Intraoperative findings showed the uterus and bilateral adnexa (ovaries and fallopian tubes) were normal, without evidence of torsion. However, a pedunculated 8 cm omental cyst located in the right lower quadrant was identified, exhibiting complete 360° torsion and localized vascular congestion (Figure 2). The cyst with torsion was carefully excised with preservation of adjacent structures. Gross examination of the specimen revealed a smooth-walled cyst containing serosanguinous fluid. Histopathological examination confirmed a chronic inflammatory omental cyst (Figure 3). Microscopic analysis demonstrated a markedly thickened fibrous wall with dense lymphoplasmacytic infiltration and focal granulation tissue formation, consistent with chronic suppurative omentitis. The cyst lumen contained aggregates of hemorrhagic necrotic cellular debris intermixed with fibrin strands and degenerated inflammatory cells. Notably, the cyst lining lacked epithelial components, and adjacent small vessels exhibited focal thrombotic changes, suggesting ischemic injury secondary to torsion. These features collectively support the diagnosis of an inflammatory omental cyst with torsion-induced complications, as shown in Figure 3. The patient reported immediate pain resolution postoperatively. She was discharged on postoperative day 2 without complications. At 3-month follow-up, she remained asymptomatic with no evidence of recurrence on ultrasound.

Figure 2 Intraoperative image of the patient with omental cyst torsion. Intraoperative findings showed a pedunculated 8 cm omental cyst located in the right lower quadrant, exhibiting complete 360° torsion and localized vascular congestion.

Figure 3 Histopathological findings of the patient with omental cyst torsion (H&E staining, ×4). Histopathological examination revealed chronic suppurative omentitis with associated cyst formation, exhibiting a hyperplastic fibrous wall and intraluminal aggregates of hemorrhagic necrotic cellular debris.

Discussion

Adnexal torsion remains a formidable diagnostic challenge, with preoperative misdiagnosis rates reaching 30–70% due to its nonspecific clinical and imaging overlap with conditions like pelvic inflammatory disease, appendicitis, and urolithiasis. Our case exemplifies a rare scenario in which omental cyst torsion radiologically mimicked ovarian pathology. The retrospective analysis highlights two imaging pitfalls: First, the obscured ovarian borders on CT prevented the exclusion of an adnexal origin. Second, the cyst’s contiguity with pelvic structures on ultrasound created a false impression of an anatomical association. These dual-modality limitations directly contributed to the preoperative misdiagnosis. A comprehensive literature review identified only two analogous reports: one describing omental fat necrosis misinterpreted as adnexal torsion, and another detailing chronic torsion of an extragonadal teratoma adherent to the omentum (5,6). To the best of our knowledge, this represents the first documented case of acute omental cyst torsion definitively managed through single-port laparoscopy. Our successful use of this minimally invasive approach demonstrates its dual value in providing both diagnostic clarification and therapeutic intervention while minimizing surgical trauma.

This case underscores the imperative to expand the differential diagnosis for reproductive-aged women presenting with pelvic cystic masses and acute abdominal pain. While omental cysts exhibit a low incidence (1/100,000 in adults), their variable anatomic distribution, often mimicking adnexal lesions, warrants inclusion alongside mesenteric cysts and retroperitoneal tumors. Furthermore, diagnostic ambiguity highlights the pivotal role of laparoscopic techniques. Single-port laparoscopy via an umbilical approach offers dual advantages: (I) precise intra-abdominal visualization for accurate diagnosis, and (II) minimally invasive therapeutic intervention—particularly valuable for young patients with high cosmetic concerns (7).

Surgical management principles emphasize complete cyst excision as the gold standard. In complex cases involving extensive adhesions or proximity to critical structures, partial omentectomy with cyst wall fulguration may be warranted. Rigorous exploration of potential occult sites, including the lesser sac and mesenteric root, is crucial to mitigate recurrence risks (8). These strategies, coupled with evolving minimally invasive technologies, reinforce the need for tailored surgical approaches in rare abdominopelvic pathologies.

Limitations

The primary limitation remains the absence of reliable preoperative discriminators between omental and adnexal pathologies, as demonstrated by our diagnostic challenge. This underscores the continued importance of laparoscopic evaluation when imaging findings are equivocal, particularly in acute settings where timely intervention is critical.

Conclusions

This case underscores that omental cyst torsion is a rare but critical differential diagnosis for acute abdomen in women. Single-port laparoscopy serves as both a diagnostic and therapeutic tool, enabling prompt management while minimizing morbidity. Clinicians must maintain a high index of suspicion for non-adnexal etiologies to avoid misdiagnosis. Further research is needed to establish preoperative diagnostic criteria and optimize surgical outcomes. Critically, omental cyst torsion should be included in the differential diagnosis of acute abdominal pain in women.

Acknowledgments

The authors thank the patient for agreeing to participate in this report and for providing her detailed medical history.

Footnote

Funding: None.

Conflicts of Interest: Both authors have completed the ICMJE uniform disclosure form (available at https://qims.amegroups.com/article/view/10.21037/qims-2025-1490/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this case were in accordance with the ethical standards of the ethics committee and the data inspectorate of West China Second University Hospital of Sichuan University (No. 460) and with the Helsinki Declaration and its subsequent amendments. Written informed consent was obtained from the patient for publication of this article and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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