CORRELATION OF MACROSCOPIC AND HISTOLOGICAL CHARACTERISTICS IN THE REGIONAL LYMPH-NODES OF PATIENTS WITH RECTAL AND SIGMOIDAL ADENOCARCINOMA

BACKGROUND/AIMS: The number of involved lymph nodes is a relevant prog nostic parameter which determines the-duration of survival in patients with colonic and rectal adenocarcinoma. The purpose of this study was to establish a correlation between the macroscopic (size and consiste ncy) and microscopic characteristics of the regional lymph nodes (type of involvement in tumor tissue, state of the capsule, adherence of th e lymph nodes, etc.) in patients with colorectal carcinoma. METHODOLOG Y: In this prospective study, 46 patients with rectal and sigmoid aden ocarcinoma were studied through randomized selection. From the resecte d specimens, a total of 736 lymph nodes were identified (average 15.66 per patient), with the precise location determined according to Enker and Philiphsken. The macroscopic and microscopic characteristics of e ach lymph node were identified. These lymph node findings were then di stributed by means of the x(2) test, while the interrelationship of ly mph node characteristics was determined by factor analysis. RESULTS: W ithin the group of ''small'' lymph nodes, 17.18% were malignant. Addit ionally, of all the malignant lymph nodes, 46.23% were less than 5mm i n diameter. Although the malignant lymph nodes were predominantly diff usely involved within the tumor tissue, 19.50% were focally involved w ithin the tumor tissue, of which 48.38% were ''small'' lymph nodes, wh ich are commonly non-palpable. Perforation of the capsule and adherenc e were more characteristic for focally mutated than for diffusely muta ted lymph nodes in the cases of malignantly mutated lymph nodes. CONCL USION: Size and consistency of the lymph nodes are not dependable para meters for appraisal of lymph node involvement in tumor tissue, the st ate of the lymph node capsule, nor the interrelation among the lymph n odes. As in the case of the primary tumor, local tumor aggression in t he lymph nodes is conditioned by the grade of differentiation, i.e. hi stologic immaturity, rather than by tumor size.