Incidental Early Stage Endometrial Adenocarcinoma Diagnosed by F-18 FDG PET-CT, Which Was Negative on Ultrasound and Nonspecific on MRI

A 65-year-old woman with a history of gastric adenocarcinoma was referred for a follow-up F-18 FDG PET-CT scan. Although there was no evidence of recurrence of her gastric malignancy, there was an incidental finding of mild focal FDG uptake in the mid uterus. This was considered suspicious, especially in a postmenopausal woman, and she was referred for further imaging. Ultrasound did not find any abnormalities, and MRI reported a nonspecific focus of mild endometrial thickening. Extensive histopathological sampling of the endometrium revealed a focus of intramucosal endometrial adenocarcinoma; the patient was diagnosed with Stage IA disease and treated surgically. This case demonstrates the importance of alerting referring physicians to even mildly FDG-avid focal abnormalities of the endometrium of postmenopausal women, despite normal or nonspecific correlative diagnostic imaging results.