| [ Summary ] |
When we diagnose subepithelial lesions of the gastrointestinal tract, a diagnosis is made according to the lesion's morphology, color, and stiffness examined using endoscopy; echogenicity and the layer of its origin examined using EUS; density examined using CT; intensity examined using MRI; and pattern of contrast examined using the latter two modalities. For example, a lipoma shows a yellowish and soft lesion, and CT and MRI reveal that its density and intensity are similar to those of adipose tissue. However, the differential diagnosis of a hypoechoic fourth layer lesion is broad and includes benign, premalignant, and malignant lesions such as leiomyomas, schwannomas, and GISTs. Therefore, we should realize that imaging alone sometimes has limitations in the diagnosis of subepithelial lesions. |