Evaluation of submucosal lesions of the large intestine: part 2. Nonneoplastic causes.

Various nonneoplastic entities may manifest as submucosal abnormalities at colorectal evaluation, and it may be difficult to distinguish between those with an intramural origin and those with an extramural origin on the basis of optical colonoscopy alone. Cross-sectional radiologic imaging, which allows evaluation of the entire bowel wall and the surrounding tissues, plays an important role in the localization and characterization of these abnormalities. However, some superficial submucosal lesions that are initially detected at computed tomographic colonography or barium enema studies may be better characterized with colonoscopy; thus, it is important to recognize the complementary uses of these diagnostic tests.

Evaluation of submucosal lesions of the large intestine: part 1. Neoplasms.

At luminal evaluation of the large intestine, any masslike protrusion that is covered by normal mucosa, whether the underlying process is intramural or extramural in origin, may be reported as a submucosal lesion. The full characterization of submucosal lesions may be difficult with optical colonoscopy alone, and endoscopic biopsy is often nondiagnostic. Cross-sectional radiologic imaging studies allow evaluation of the entire thickness of the bowel wall and surrounding tissues and often provide additional information with regard to lesion origin, internal composition, and extent of disease.

EUS and fine-needle aspiration in the evaluation of mediastinal masses superior to the aortic arch.

Background: Mediastinal lesions require a tissue diagnosis. This cannot be obtained with CT-guided biopsy or bronchoscopy in many patients. Co-morbid diseases increase the risk of mediastinoscopy in some of these patients.