Increased 18F-FDG uptake of widespread endometriosis mimicking ovarian malignancy

Endometriosis is a benign disease characterized by the implantation of functional endometrial tissue in ectopic locations. We present a case of a 42-year-old woman with widespread endometriosis that mimicked ovarian malignancy on FDG PET/CT. Increased FDG uptake was observed not only in the right ovary, but also in the liver capsule, perihepatic nodules, greater omentum, and the mesentery. This case indicates that widespread endometriosis may be a cause of multiple FDG uptakes in women of reproductive age and should always be kept in mind in the differential diagnoses of suspicious malignancy.