A woman in her mid-20s who was 8 weeks pregnant presented to the emergency department for abdominal pain localized in the right iliac fossa (RIF), numbness in the right lower limb, and nausea and vomiting. On examination she had tenderness in the RIF with a positive Blumberg sign; blood testing showed leukocyte count 10 450/μL (to convert to ×109/L, multiply by 0.001) without any shift, C-reactive protein 1.29 mg/dL (to convert to nanomoles per liter, multiply by 0.331), and hemoglobin 11.4 g/dL (to convert to grams per liter, multiply by 10). The Alvarado score was 7. A transabdominal ultrasonographic scan showed a tubular structure in the RIF consistent with a mildly inflamed appendix and stratification of the appendiceal wall (7 mm in the proximal and 11 mm in the appendiceal distal tract). A small amount of free fluid was present in the Douglas pouch. A transvaginal ultrasonographic scan confirmed normal intrauterine gestation with a vital embryo. Working diagnosis was uncomplicated appendicitis and initial conservative management was amoxicillin clavulanate because of the potential risks of miscarriage associated with performing an avoidable appendectomy and general anesthesia during early gestation. The patient initially improved and was discharged home 2 days later with an Alvarado score of 4; oral antibiotic therapy was continued. Three days later she returned to the emergency department with recurrent pain; the clinical and ultrasonographic findings were unchanged, without evidence of complicated appendicitis, intra-abdominal fluid collection, or abscess. The Alvarado score was 5. The patient was admitted to the surgical ward and given intravenous antibiotics. In the next 48 hours the symptoms and pain did not resolve, although inflammatory markers were low and the patient was not septic. The surgeon on call requested an urgent magnetic resonance imaging (MRI) investigation (Figure 1).