Clinical significance of type VI pit pattern subclassification in determining the depth of invasion of colorectal neoplasms

Figure 1 Classification of pit patterns of colorectal lesions.

Figure 2 Magnifying features of colorectal neoplasm (crystal violet): A: Regular pit margins; B: Irregular pit margins; C: Clear staining characteristics of the areas between pits; D: Unclear staining characteristics of the areas between pits; E: High residual pit density; F: Low residual pit density; G: Narrow intervening membrane between pits; H: Wide intervening membrane between pits.

Figure 3 Type IIa + 10IIc lesion, 12 mm in diameter. A: Standard colonoscopic view; B: Standard colonoscopic view with indigo carmine spraying; C, D: Magnifying colonoscopic picture with crystal violet staining reveals type V_I pit pattern. Irregular pit margins, unclear staining characteristics of the areas between pits, > 5 mm area of type V_I pit pattern, high residual pit density, and narrow intervening membrane between pits is revealed; E: Cross-section (hematoxylin-eosin, × 8) of a surgically resected specimen showing submucosal invasion (1800 &mgr;m); F: Low-power view (hematoxylin-eosin, × 40) of type V_I pit pattern. Muscularis mucosae have disappeared. Desmoplastic reactions are mild to moderate. In this case, lymph node metastasis was not detected.