Initial Radiological Misdiagnosis of Choledochal Cyst in Pregnancy Leading to Unnecessary Laparotomy: The Approach to Abdomino-Pelvic Cyst and Management

A 20-year-old primary gravida at 26 weeks of gestation presented with acute abdominal pain. At a rural facility that she had consulted earlier, abdominal pelvic ultrasonography had suggested adnexal pathology, most likely ovarian torsion, and an exploratory laparotomy had been performed. No adnexal pathology had been found, and the procedure had been abandoned. The patient was transferred to our center in hemodynamic instability. Repeat ultrasonography identified a large right subhepatic cystic lesion with differentials including choledochal cyst (CC), benign retroperitoneal cyst, and ovarian/paraovarian cyst. MRIs subsequently confirmed a giant right upper quadrant cyst compressing hepatobiliary structures, correlating with the development of clinical jaundice. This clarified the etiology and eliminated the need for further unnecessary gynecologic surgery. The patient was managed with ultrasound-guided percutaneous drainage, which safely decompressed the biliary system, relieved mass effect, and reduced rupture risk in the context of high maternal-fetal surgical risk. The intervention stabilized the patient, facilitated definitive cyst excision before normal vaginal delivery at 36+6 weeks. Based on this experience and a review of the relevant literature, we suggest that in selected cases of undifferentiated abdomino-pelvic cysts during pregnancy, particularly in resource-limited or emergency settings without access to advanced imaging, ultrasound-guided percutaneous drainage may be a valuable diagnostic and temporizing measure. This approach can safely bridge patients to definitive management and may help avoid unnecessary laparotomy.