Small Bowel Mucosal Disease SMALL BOWEL MUCOSAL DISEASE A diverse array of disorders can be diagnosed with small bowel biopsy. However, in our experience, the evaluation of nonneoplastic small bowel…

Inflammatory Disorders of the Esophagus: Reflux and Nonreflux Types GASTROESOPHAGEAL REFLUX DISEASE (REFLUX ESOPHAGITIS-GERD/GORD) Definition of GERD Gastroesophageal reflux disease (GERD) is defined as at least weekly heartburn, acid regurgitation,…

Mesenchymal Tumors INTRODUCTION Mesenchymal tumors of the gastrointestinal (GI) tract can be classified as shown in Table 7-1. Some are unique to the GI tract (e.g., gastrointestinal stromal tumor [GIST],…

Polyps and Tumors of the Esophagus Most tumors of the esophagus that cause symptoms are malignant. Of these, over 95% are either squamous cell carcinoma or adenocarcinoma. Squamous cell carcinoma…

Stomach: Normal Structures and Developmental Abnormalities EMBRYOLOGY Stomach The stomach appears at 14 weeks as a fusiform dilation of the caudal part of the foregut. The dorsal border grows faster…

Motility Disorders DIVERTICULAR DISEASE OF THE SMALL AND LARGE INTESTINES Definition Intestinal diverticula are outpouchings, herniations, or protrusions (all tend to be sued as synonyms) of mucosa and submucosa through…

Esophagus: Normal Structures, Developmental Abnormalities, and Miscellaneous Disorders STRUCTURE OF THE ESOPHAGUS Anatomy The esophagus is a muscular tube that is lined with stratified squamous epithelium. Its average length is…

Gastrointestinal Manifestations of Extraintestinal Disorders and Systemic Disease INTRODUCTION Gastrointestinal symptoms are common in primary extraintestinal diseases as well as in systemic disorders. Such manifestations may occur in a variety…

Disorders of Endocrine Cells INTRODUCTION AND HISTORICAL PERSPECTIVE The gastrointestinal (GI) tract is loaded with endocrine cells that vary from one site to the other based on the functional necessities…

Lymphoproliferative Disorders of the Gastrointestinal Tract OVERVIEW Introduction The gastrointestinal (GI) tract contains the largest aggregate of lymphoid tissue aside from lymph nodes, and it is the most frequent site…