TCV Finding: Cobblestone Sign

Etymology The term “cobblestone sign” arises from the visual resemblance of the affected mucosa to cobblestone pavements, attributed to alternating areas of ulceration and intervening edematous mucosa.

AKA

• Cobblestone appearance
• Cobblestone mucosa

What is it? The cobblestone sign is a radiological and endoscopic finding characterized by a patchy pattern of mucosal ulcerations separated by raised, intact, or edematous mucosa. It is commonly associated with Crohn’s disease.

Caused by:

• Most common: Chronic inflammatory processes leading to mucosal ulceration and transmural involvement (11, 14).
  • Inflammation/Immune: Granulomatous inflammation causing segmental involvement of the gastrointestinal tract (12).
  • Infection: Intestinal tuberculosis and other infections that mimic Crohn’s disease (13).
  • Neoplasm: Rarely associated with neoplastic processes; typically excludes malignancy.
  • Mechanical: Bowel obstruction secondary to strictures.
  • Trauma: Post-surgical changes mimicking cobblestone appearance.
  • Metabolic: Nutritional deficiencies impacting bowel integrity.
  • Circulatory: Ischemic changes resulting in cobblestone-like mucosal patterns.
  • Inherited/Congenital: No specific congenital associations.
  • Iatrogenic: Radiation enteritis leading to a cobblestone-like appearance.
  • Idiopathic: Crohn’s disease often categorized as idiopathic, with unclear primary etiology.
• Chronic inflammatory processes leading to mucosal ulceration and transmural involvement (11, 14).
• Granulomatous inflammation causing segmental involvement of the gastrointestinal tract (12).

Resulting in:

• Patchy mucosal destruction.
• Segmental thickening and fibrosis of the bowel wall.

Structural Changes:

• Ulceration and fissuring.
• Edematous mucosa surrounded by inflamed tissue.
• Transmural fibrosis leading to strictures and narrowing.

  Parts:

  • Most commonly involves the terminal ileum and proximal colon but may affect any segment of the gastrointestinal tract (3, 5).

  Size:

  • Segmental involvement; varies based on the extent of the inflammatory process.

  Shape:

  • Patchy, irregular mucosal ulcerations interspersed with raised mucosal islands.

  Position:

  • Localized to the terminal ileum and adjacent bowel but may be diffuse in severe cases.

  Character:

  • Alternating ulcerated and edematous mucosa, creating a nodular appearance.

  Time:

  • Chronic and progressive over months to years in untreated or poorly controlled disease.

Diagnosis:

• Combination of imaging and endoscopic findings correlating with clinical symptoms and histology.

Clinical:

• Symptoms include chronic diarrhea, abdominal pain, and weight loss (17).
• May present with obstructive symptoms due to strictures.

Radiology:

• Patchy segmental inflammation with characteristic cobblestone appearance on cross-sectional imaging.

Labs:

• Elevated inflammatory markers such as CRP and ESR.
• Positive fecal calprotectin in active inflammation.

Radiology Detail:

X-Ray/Fluoroscopy/Barium Findings:

• “Cobblestone appearance” seen on barium studies due to alternating mucosal ulceration and edema (3, 4).
• Narrowing of the lumen and strictures in advanced disease. Associated Findings:
• Skip lesions and fistulas.
• String sign indicating severe stenosis.

CT Findings:

• Segmental bowel wall thickening and hyperenhancement (5).
• Creeping fat adjacent to affected segments. Associated Findings:
• Fistulas, abscesses, and lymphadenopathy.

MRI Findings:

• Wall thickening with mucosal enhancement and T2 hyperintensity indicating active inflammation (9, 10).
• “Cobblestone” appearance from alternating inflamed and spared segments (8). Associated Findings:
• Transmural inflammation, fistulas, and abscesses.

US Findings:

• Thickened bowel wall with increased vascularity on Doppler imaging. Associated Findings:
• Enlarged mesenteric lymph nodes.

Other Relevant Imaging Modalities PET CT/NM/Angio:

• FDG uptake in inflamed bowel segments may support the diagnosis in equivocal cases.

Differential Diagnosis:

• Intestinal tuberculosis (13).
• Ischemic colitis.
• Behçet’s disease.
• Radiation enteritis.

Recommendations:

• Cross-sectional imaging (MRI or CT) for assessing extent and complications.
• Endoscopic biopsy to confirm histological diagnosis.

Key Points and Pearls:

• The cobblestone sign is a hallmark of Crohn’s disease and reflects chronic, patchy transmural inflammation.
• Barium studies remain valuable in identifying this sign in resource-limited settings.
• Advanced imaging modalities like MRI and CT provide detailed assessment of transmural and extraluminal disease involvement (6, 9).

References