Classification of Colon Polyps

Introduction

• Topic: Classification of colon polyps
• Method: Learn classification and refer to endoscopic images

Paris Classification of Polyps

Pedunculated Polyp (1p)

• Description: Polyp with a stalk (pedicle)
• Mnemonic: Think of a mushroom with a stalk and head

Semi-Pedunculated Polyp (1sp)

• Description: Smaller stalk than pedunculated, but still visible

Sessile Polyp (1s)

• Description: Height more than the width, height above the size of biopsy forceps

Superficial Elevated Polyp (2a)

• Description: Elevated above mucosa, height less than biopsy forceps
• Size: If >10mm, known as a 'laterally spreading tumor'
  • Granular Surface: Laterally spreading tumor, granular type
  • Smooth Surface: Laterally spreading tumor, non-granular type

Flat Lesion (2b)

• Description: Almost at the same level as mucosa

Depressed Lesion (2c)

• Description: A lesion with a depressed area
• Mixed Lesion: 2c/2a (depressed with one edge elevated)

Important Images to Remember

• Pedunculated Polyp (1p) & Semi-Pedunculated Polyp (1sp)
• Sessile Polyp (1s)
• Superficial Elevated Polyp (2a)
• Flat Lesion (2b)
• Depressed Lesion (2c)
• Mixed Lesion (2c/2a)

Clinical Significance

• Depressed Lesions (2c): High risk for cancer even when small
• Other Lesions: Can be benign or cancerous if large

Endoscopic Images

• Pedunculated Polyp (1p): Stalk and head, precancerous area in head, cut stalk to remove
• Sessile Polyp (1s): Height > biopsy forceps
• Superficial Elevated Polyp (2a): Granular surface, >10mm
  • Laterally Spreading Tumor (Granular Type)
  • Laterally Spreading Tumor (Non-Granular Type)
• Depressed Lesion (2c): Not available, but mixed lesion shown (2c/2a)