Relationship between histopathological features and type V pit pattern determined by magnifying videocolonoscopy in early colorectal carcinoma

Background: The aim of the present study was to clarify the relationship between the histopathological features and type V pit pattern of early colorectal carcinoma. Methods: We examined the relationship between the type V pit pattern subtypes, the depth of submucosal invasion and the degrees of desmoplastic reaction, residual pit density and destruction of the intervening membrane between pits on the tumor surface in 135 cases of early colorectal carcinoma. The examinations involved magnifying videoendoscopy with indigo carmine dye spraying and crystal violet staining. The pit patterns were classified as one of two grades (V I , V N ), and V N was further divided into three subtypes (A, B and C). The data obtained were evaluated by χ 2 test, with significance accepted at < 0.05% for each analysis. Results: There were 64 V I , 24 V N ‐A, 28 V N ‐B and 19 V N ‐C lesions. The incidence of massive submucosal invasion (sm2, sm3) was significantly higher in V N ‐B and V N ‐C lesions than in V I and V N ‐A lesions ( P < 0.05). Among V N pit pattern lesions, depth of submucosal invasion of V N ‐B and V N ‐C lesions was significantly greater than that of V N ‐A lesions ( P < 0.01). The incidence of severe desmoplastic reaction in V N ‐B and V N ‐C lesions was significantly greater than that in V I lesions ( P < 0.01). The incidence of severe desmoplastic reaction in V N ‐C lesions was significantly greater than that in V N ‐A lesions ( P < 0.05). The incidence of low residual pit density in V N ‐C lesions was significantly greater than that in all other type V lesions. The incidence of mild to moderate and severe destruction of the intervening membrane between pits in V N lesions was significantly higher than that in V I lesions. Conclusions: Type V pit pattern subclassification is useful for predicting the depth of submucosal invasion in early colorectal carcinomas. The type V pit pattern subtypes are related to the degrees of desmoplastic reaction, the residual pit density and destruction of the intervening membrane between pits on the tumor surface.