Vascular Lesions A number of vascular lesions affect the large intestine. In this chapter we will deal with nonneoplastic vascular abnormalities. Vascular tumors are covered in Chapter 19. Portal Colopathy…

Disorders Associated with Granulomas and Macrophage Collections Granulomas and collections of macrophages complicate various gastrointestinal conditions, as extensively discussed in Chapter 6. Macrophage collections take the form of both compact…

Lesions Associated with Increased Numbers of Eosinophils Occasionally one encounters biopsies in which the most striking change is a marked increase in the number of eosinophils. Their presence can suggest…

Acquired Abnormalities Diverticular Disease Etiology Colonic diverticular disease has become increasingly prevalent in the United States and other economically developed countries. Its incidence varies with national origin, cultural background, and…

Microscopic Colitis General Comments Some patients with chronic idiopathic diarrhea have histologic evidence of colitis even though their colons appear normal by barium enema and by colonoscopy; such patients have…

Ischemic Colitis General Comments Acute ischemia results from an acute reduction in the blood flow resulting from an acute occlusive event or as a result of a decreased blood flow….

Neutropenic Enterocolitis (Typhlitis) Neutropenic enterocolitis, also known as typhlitis, agranulocytic colitis, neutropenic enteropathy, and ileocecal syndrome, traditionally affects children treated for leukemia and other conditions. It may complicate chemotherapy for…

Phlegmonous Colitis Phlegmonous colitis is a very rare disorder that presents as submucosal cellulitis. It is rarer than its gastric counterpart, discussed in Chapter 4 (379). The bowel appears thickened…

Radiation Injury Radiation injury causes two types of gastrointestinal damage. The first is the radiation damage itself; the second is the long-term consequence of radiation (i.e., ischemic changes or cancer…