MRI diagnosis of concurrent perforated appendicitis and acute calculous cholecystitis in late pregnancy: a case report

Background Acute appendicitis in pregnancy often presents atypically, and diagnostic delay increases the risk of perforation. Concomitant biliary pathology can further obscure the clinical picture, particularly in late gestation. Case A 19-year-old woman at 35 weeks’ gestation presented with 1 day of dull right lower quadrant pain with associated right upper quadrant discomfort. Laboratory testing showed leukocytosis (WBC 16.34 K/μL; neutrophils 82.8%) and a markedly elevated hs-CRP (239.21 mg/L). Ultrasound demonstrated an impacted gallbladder neck stone, but the appendix was not visualized. MRI identified an enlarged appendix (14 mm) with periappendiceal inflammation and moderate free fluid consistent with perforated appendicitis with peritonitis, and concurrently demonstrated imaging features of acute calculous cholecystitis with mild bile duct dilatation. Emergency laparoscopy confirmed a necrotic, leaking appendix with localized purulent peritonitis, and laparoscopic appendectomy was performed. Recovery was uncomplicated, and the pregnancy progressed to an uncomplicated vaginal delivery at 38 weeks’ gestation of a healthy newborn. Conclusion In late pregnancy, overlapping right-sided abdominal pain may reflect concurrent surgical pathology. MRI can rapidly clarify diagnosis and guide timely operative management to reduce maternal-fetal risk.