Lymphocytic Colitis
Differential Diagnosis
- Similar findings may be seen in biopsies taken from a variety of processes:
- Diverticulosis
- Crohn disease
- Infectious colitis
- Autoimmune enteropathy
- Usually pediatric
- Usually more severe deep inflammation and crypt damage
- Celiac sprue
- Up to 30% of celiac disease patients may have lymphocytic colitis-like findings
- If such diseases have not been ruled out clinically, the findings are best diagnosed as “Colonic Intraepithelial Lymphocytosis” with a comment describing the differential diagnosis
- Chronic colitis is a term best not used as a pathologic diagnosis
- Moderate numbers of lymphocytes and plasma cells are normal in the lamina propria of the large intestine
- The chronic changes associated with inflammatory bowel disease are better diagnosed as “crypt distortion” with a comment that they are consistent with chronic inflammatory bowel disease
- Lymphocytic colitis and collagenous colitis are distinguished by the presence of a thickened collagen layer only in the latter
- They both exhibit a prominent intramucosal lymphocytic infiltrate
- The thickened collagen layer may be variably distributed
- Multiple biopsies may need to be examined
| Incidental Chronic Colitis | Lymphocytic Colitis |
| Crypt distortion and dropout | No significant crypt distortion |
| Basal plasmacytosis | Increase in lamina propria lymphocytes and plasma cells with intraepithelial lymphocytes |
| Isolated disease | Usually multifocal |
| Virtually restricted to cecum/right colon | May involve entire GI tract |
| Incidental, asymptomatic | Intractable watery diarrhea in most cases |
