FDG PET/CT and Histopathologic Characteristics of Low-Grade Appendiceal Mucinous Neoplasm with Pseudomyxoma Peritonei.

A 50-year-old woman presented a rapidly proliferative cystic lesion in the left pelvis as displayed by sonography. Exploratory laparoscopy with omental biopsy suggested pseudomyxoma peritonei (PMP). An 18F-FDG PET/CT revealed scalloping of the liver surface with an associated extrahepatic lesion exhibiting moderate FDG avidity and strand-like FDG uptake within a left-sided septated ovarian cyst. The diagnosis of low-grade appendiceal mucinous neoplasms was proven after cytoreductive surgery. This case provided important imaging features on 18F-FDG PET/CT that directed the pre-operative diagnosis and the initiation of treatment.