Abstract
Objective: Gastrointestinal stromal tumors(GIST)develop as submucosal tumors within the gastrointestinal tract. We describe a case in which ultrasound revealed duodenal GIST that had been undetected by upper gastrointestinal imaging in an asymptomatic 46-year-old male patient.
Case: The ultrasound showed a circular tumor 3 cm in diameter with well-defined margins, originating from the duodenum and located posterior to the body of the gallbladder and near the head of the pancreas. Ultrasonic images of the tumor were mottled and isoechoic with hyperechoic regions compatible with normal liver parenchyma. Color doppler indicated very little blood flow at the tumor periphery. CT and MRI positioned the tumor in the second portion of the duodenum. The tumor appeared heterogeneous on contrast-enhanced CT. MRI showed a slight low-signal-intensity area on the T1-weighted image, and dynamic MRI showed heterogeneous contrast enhancement in the early phase. Partial duodenectomy was performed, and the tumor was diagnosed as a low-risk duodenal GIST on the basis of histopathologic findings.
Conclusions: Owing to Because of the exoenteric growth pattern, the tumor was not observed in upper gastrointestinal imaging, but was readily detected by ultrasound since there was no interference from abdominal gas. Ultrasound can provide real-time identification of tumor location, and has applications in the detection of submucosal tumors.
