A Giant Duodenal Leiomyoma Showing Increased Uptake on 18F-Fluorodeoxyglucose Positron Emission Tomography

Abstract EN

Background.

Although 18F-fluorodeoxyglucose positron emission tomography (FDG-PET/CT) is now widely used in their differential diagnosis, it is sometimes difficult to distinguish between benign and malignant diseases.

Case Presentation.

A 44-year-old woman was found to have abnormalities on health screening.

Magnetic resonance imaging for detailed examination showed an intra-abdominal tumor measuring 12 cm in the major axis near the cranial end of the uterus.

Upper gastrointestinal tract endoscopy showed a tumor with an ulcer in the third part of the duodenum, involving half the circumference.

Heterogeneous uptake was observed within the tumor on FDG-PET/CT.

Based on these findings, the patient underwent surgery for suspected primary malignant lymphoma of the duodenum or gastrointestinal stromal tumor.

Laparotomy revealed a 12 cm tumor in the third part of the duodenum.

Partial duodenectomy and end-to-end duodenojejunostomy were performed.

Pathological findings showed a solid tumor growing from the muscle layer of the duodenum to outside the serous membrane; based on immunostaining, it was diagnosed as a leiomyoma.

Conclusions.

Duodenal leiomyomas are originally benign; to date, there have been no reports of uptake in duodenal leiomyomas on FDG-PET/CT; therefore, our case is rare.

Leiomyomas should be considered in the differential diagnosis of duodenal neoplastic diseases.