Crohn's Disease

Introduction

In this section, Mike Dado introduces himself and the virtual slide box from Duke University School of Medicine. He then proceeds to examine some areas close to normal.

Identifiable Tissue of Origin

• The slide contains identifiable tissue of origin, which is the colon or large intestine.

• The distinct layers of the colon are visible: mucosa, submucosa, muscularis propria, and serosa.

Normal Epithelial Cells

• The normal epithelial cells of the colon contain abundant mucin-filled cells called goblet cells.

• The lamina propria typically contains inflammatory-type cells such as lymphocytes, plasma cells, and occasional eosinophils.

Ulceration

• An area of ulceration is present on the slide.

• Acute inflammatory cells such as neutrophils are likely present in the ulcerated area.

• Chronic inflammation or inflammatory cells such as lymphocytes and plasma cells are also present in the ulcerated area.

Causes of Ulcers in Colon

In this section, Mike Dado discusses various causes of ulcers in the colon.

Infectious Diseases

• Bacteria like Salmonella Shigella E.coli can cause ulcers in the colon.

• Clostridium difficile can cause pseudomembranous colitis leading to ulcers in the colon.

• Viral infections such as CMV or HSV can cause ulcers in immunocompromised patients.

Ischemia

• Intussusception or torsion can cause ulcers in the colon.

Inflammatory Bowel Diseases (IBD)

• IBD can cause ulceration in the colon.

• To diagnose IBD, more than an ulcer is needed. Other changes in the colon are required to suggest a chronic process or ongoing damage.

• Crypt distortion and abnormal gland appearance are signs of chronic colitis.

Crohn's Disease vs Ulcerative Colitis

In this section, Mike Dado discusses the differences between Crohn's disease and ulcerative colitis.

Colon Cancer Risk

• Patients with ulcerative colitis have an increased risk of developing colon cancer and undergo regular surveillance biopsies.

• Patients with Crohn's disease have a lower increased risk of colon cancer but are more prone to develop fissures or transmural inflammation of the colon leading to fissures and other problems.

Diagnosis

• Distinguishing between Crohn's disease and ulcerative colitis can be tricky but is important for surveillance screening and colon cancer risk.

Crohn's Disease vs Ulcerative Colitis

In this section, the speaker discusses the differences between Crohn's disease and ulcerative colitis.

Transmural Inflammation

• Crohn's disease has transmural inflammation, which means inflammation all the way through the wall of the colon.

• Ulcerative colitis is usually limited to the mucosa.

Contiguous vs Discontinuous Inflammation

• The endoscopist will look for whether or not the inflammation is contiguous or discontinuous.

• Ulcerative colitis usually starts at the rectum and progresses up without skip lesions or it's usually continuous.

• Crohn's disease lesions can be discontinuous.

Location of Inflammation

• Ulcerative colitis starts at the rectum and progresses north from there.

• Crohn's disease can involve small intestine whereas ulcerative colitis does not involve small intestine.

• Acute ulceration or chronic damage can occur anywhere from mouth to anus in Crohn's disease.

Granulomas

• Granulomas are associated with Crohn's disease but not with ulcerative colitis.

• The granulomas associated with crohn's disease are more well-formed than those seen in other contexts in colon tissue.

Summary of Colon Tissue Findings

This section provides a summary of findings related to colon tissue examination.

Loss of Mucosal Surface

• There is a complete loss of mucosal surface due to an ulcer that contains fibrin and neutrophils.

Chronic Damage

• Evidence of chronic damage includes Paneth cell metaplasia, which is associated with chronic damage to colon tissue.

Granulomatous Inflammation

• Granulomas are present in the colon tissue, which is not classic for Crohn's disease but can occur in many different contexts.

• Overall, the clinical picture suggests that this is a case of Crohn's disease.