BACKGROUND: In Brazil, colorectal carcinoma is the third cause of death by malignant tumors among women, and the fifth among men. Lymph node involvement is one of the most relevant prognostic maker in these tumors. AIM: To study lymph node involvement in colorectal carcinoma in relationship to biological behavior and tumor location. PATIENTS AND METHODS: One hundred and eight five colorectal carcinoma cases were studied. Lymph node involvement was analyzed according to tumor location, diameter, vessel invasion, and TNM staging. RESULTS: Three thousand nine hundred and six lymph nodes were harvested in 185 patients (21.1 lymph nodes/patient). Metastasis were detected in 399/2,573 peritumoral lymph nodes (15.5%) and in 72/1,333 non-peritumoral lymph nodes (5.4%). Eighty-six patients presented metastasis; in these patients 471/1942 lymph nodes were compromised. In 26 patients peritumoral and non-peritumoral lymph nodes were involved; in 57 cases metastasis were detected only in peritumoral lymph nodes and in 3, only non-peritumoral lymph nodes were involved. The number of lymph node was higher among cecal tumors and smaller in the rectum and sigmoid. There was a positive correlation between the number of metastatic lymph node and pT, tumor diameter and lymphatic and venous invasion; there was a negative correlation between lymph node involvement and lymphocytic response; pN was significantly associated with pT. CONCLUSIONS: Colorectal carcinoma involves preferentially peritumoral lymph node, but in 29 patients (15,7%) non-peritumoral lymph nodes were affected, which is important for tumor staging and prognosis. pN and the number of metastatic lymph nodes were associated with other behaviour markers.
Colorectal neoplasms; Carcinoma; Lymph nodes; Lymphatic metastasis
