GASTROINTESTINAL-TRACT DUPLICATIONS - CLINICAL, PATHOLOGICAL, ETIOLOGIC, AND RADIOLOGIC CONSIDERATIONS

Gastrointestinal tract duplications are uncommon congenital abnormalit ies. By definition, they are located in or adjacent to the wall of par t of the gastrointestinal tract, have smooth muscle in their walls, an d are lined by alimentary tract mucosa. The lining mucosa is not neces sarily that of the adjacent segment of the gastrointestinal tract. The only clinically important ectopic tissues are gastric mucosa and panc reatic tissue. Although ectopic gastric mucosa is found in duplication s at all levels of the gastrointestinal tract, it is most prevalent (4 3%) in esophageal duplications. Peptic ulcer within this ectopic tissu e can account for unusual, often misleading symptoms. Ectopic pancreat ic tissue is most common (37%) in gastric duplications and is associat ed with pancreatitis and elevated amylase levels. Detection of associa ted vertebral anomalies is a helpful clue in the radiographic diagnosi s of duplications. Barium studies usually reveal an intraluminal, intr amural, or extrinsic mass, and ultrasonography (US) demonstrates its c ystic nature. When US findings are inconclusive, computed tomography c an be used to show the true nature, location, and extent of the lesion , as well as associated vertebral anomalies and possible other duplica tions. Technetium-99m pertechnetate scintigraphy provides definitive e vidence of a duplication when it contains ectopic gastric mucosa and i s particularly useful for suspected esophageal, duodenal, and small bo wel lesions.