When evaluating a colonic biopsy for possible infectious processes, the surgical pathologist must first attempt to differentiate histologic changes suggesting infectious colitis from other inflammatory processes, especially chronic idiopathic inflammatory…
■ Fibrous obliteration of the appendiceal lumen (neural hyperplasia) Clinical features There are no specific features as this is typically an incidental finding in about one third of appendices excised…
Idiopathic inflammatory bowel diseases include the chronic crypt destructive colitides, chronic ulcerative colitis, and Crohn’s disease. Ulcerative colitis and Crohn’s disease differ in natural history, clinical and pathologic associations, effective…
■ Collagenous colitis Clinical features Patients with collagenous colitis (CC) present with a history of chronic watery diarrhea. Colonoscopy typically shows normal or near normal mucosa, although there are a…
■ Gastrointestinal stromal tumor Gastrointestinal stromal tumors (GISTs) are soft tissue tumors that either express C-kit/CD117 protein or have C-KIT or platelet-derived growth factor receptor-α ( PDGFRA ) mutations and…
■ Acute erosive/hemorrhagic gastritis (stress gastritis) Acute erosive/hemorrhagic gastritis is characterized by an acute gastric injury with an abrupt onset of abdominal pain and bleeding, usually associated with intake of…
■ Peptic duodenal diseases Clinical features Peptic duodenitis and peptic ulcer disease (PUD) represent a continuum of the same disease process, namely acute and chronic inflammation of the duodenal mucosa…
The small intestine represents 75% of the length and 90% of the surface area of the gastrointestinal tract, yet neoplasms of the small intestine are rare, accounting for only 1%…
Gastric carcinomas have a variety of precursors that can be identified histologically. Precursor lesions can be broadly classified into categories of either gastric epithelial dysplasia (GED) for flat (grossly normal)…
■ Fibrovascular polyps of the esophagus Clinical features These lesions may not be truly neoplastic but are included here as tumefactions that are occasionally encountered in clinical practice. Fibrovascular polyps…
