Ischemic Colitis
Definition
- Colitis secondary to arterial or venous vascular compromise
Alternate/Historical Names
- Acute or chronic intestinal ischemia
- Acute or chronic mesenteric ischemia
Diagnostic Criteria
- Early lesions characterized by superficial mucosal hemorrhage, edema and necrosis
- Necrosis usually spares base of crypts and muscularis propria
- Leaves residual atrophic microcrypts
- Capillary thrombi frequent
- Minimal inflammation in very early lesions
- Submucosal edema may produce discrete blebs
- Sloughed necrotic mucosa may produce a microscopic appearance of a pseudomembrane
- Later lesions may exhibit granulation tissue, submucosal fibrosis and atrophy
- Frequent hyalinization of lamina propria
- May mimic chronic architectural changes of inflammatory bowel disease
- Hemosiderin is frequently present in mucosa and submucosa
- Submucosal fibrosis may lead to stricture formation
- Occasional findings
- Paneth cell metaplasia
- Endocrine cell hyperplasia
- Severe, full thickness lesions lead to gangrene and perforation
- Usually sharply defined area of involvement
- Most common location is splenic flexure watershed zone
- All other regions of colorectum can be involved
- May form a polyp or tumor mass
- In resection specimens, vascular changes can be seen in about half of cases
- Arterial thrombus or embolus is most common
- Frequently atherosclerotic
- Venous thrombus
- Causes other than primary vascular disease include radiation, uremic colitis and obstructive colitis
- Most cases without vascular cause are due to hypoperfusion
- Most cases in patients over age 50
- Usually due to cardiovascular disease
- Rare cases involving younger patients more often due to non-vascular causes
- Arteritis
- Coagulation disorders
- Drugs, including cocaine and oral contraceptives
- May be seen in long distance runners
- Patchy epithelial atrophy may represent the effect of transient ischemic colitis
- Focal hyalinized lamina propria with atrophic microcrypts
Robert V Rouse MD
Department of Pathology
Stanford University School of Medicine
Stanford CA 94305-5342
Original posting : November 11, 2009
Differential Diagnosis
- Quiescent colitis in inflammatory bowel disease may be histologically indistinguishable from chronic ischemia
- Clinical correlation is necessary
- Hemosiderin laden macrophages may suggest ischemia
- Colitis due to E coli O157:H7 may be histologically indistinguishable from acute ischemia
- Clinical correlation is necessary
Pseudomembranous Colitis |
Ischemic Colitis |
Diffuse |
Localized, may form a mass |
No hyanization of lamina propria |
Hyalinized lamina propria |
Occasional atrophic crypts |
Atrophic microcrypts common |
Usually only superficial necrosis |
Necrosis frequently transmural |
C difficile titer elevated |
C difficile titer negative |
Associated with antibiotic therapy |
Not associated with antibiotic therapy |
- Acute ischemic colitis bears no resemblance to incidental chronic colitis
Bibliography
- Noffsinger A, Fenoglio-Preiser CM, Maru D, Gilinisky N. Gastrointestinal Diseases, AFIP Atlas of Nontumor Pathology, First Series, Fascicle 5, 2007.
- Dignan CR, Greenson JK. Can ischemic colitis be differentiated from C difficile colitis in biopsy specimens? Am J Surg Pathol. 1997 Jun;21(6):706-10.
- Orikasa H, Katayama I. Differentiating ischemic colitis from other colitides. Am J Surg Pathol. 1998 Jun;22(6):773-4.
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