Clinicopathological characteristics of colorectal carcinoid tumor focusing on risk factors of lymph node metastasis

Abstract

The aim of the present study was to evaluate risk factors of lymph node metastasis of colorectal carcinoid tumor in less than 20mm diameter and significance of specific staining method when assessing their lymphatic and venous invasion.
A total of 51 cases with colorectal carcinoid tumor were resected endoscopically or surgically from April 2001 to April 2010. We clinicopathologically investigated them focusing on risk factors of lymph node metastasis. We also evaluated relasionships between “lymphatic and venous invasion” and nodal metastasis with both standard HE 2staining method and specific staining method (D2-40 and Victoria blue VB) .
As a result, metastatic factors of colorectal carcinoid were considered to be reddish color, semipedunculated form, depression of tumor surface, lymphatic invasion and venous invasion with statistical significance (P<0.05) . As for relashionship between “lymphatic and venous invasion” and nodal metastasis, specific staining method revealed less specificity with statistical significance (P<0.05) than standard HE staining method.
These results indicate that “lymphatic and venous invasion” are important risk factors of lymph node metastasis in colorectal carcinoid tumor under 20mm in size, however the significance of “lymphatic and venous invasion” with specific staining method needs much more discussion.