Use of FDG/PET CT to diagnose malignancy as the cause of mucocele of the appendix

Mucocele of the appendix is an uncommon condition characterized by luminal distension and accumulation of a mucoid material. Occasionally, it can be caused due to malignancy like cystadenocarcinoma, and the preoperative diagnosis of which is very rare. We report a case of a 64-year-old lady presenting with intermittent abdominal pain diagnosed on ultrasonography as a mucocele where preoperative ¹⁸F-flurodeoxyglucose positron emission tomography/computerized tomography (FDG PET/CT) findings raised a strong suspicion of malignancy. FDG PET/CT findings brought about a change in therapeutic plan, and the patient was considered for a more extensive surgical resection. The final histopathology revealed cystadenocarcinoma as the cause of appendicular mucocele, a finding hitherto undescribed on FDG PET/CT.