Effect of cholangitis on pre-operative evaluation of regional lymphadenopathy by CT in pancreato-biliary malignancies.

Abstract

e15651 Background: Regional lymph nodes metastasis is a poor prognostic factor in pancreato-biliary malignancies. CT findings like lymph node size > 10mm, irregular shape, heterogenous enhancement, conglomeration and infiltration can suggest metastatic involvement. Cholangitis can induce reactive changes in regional lymph nodes. This study aimed to find if episodes of cholangitis interfere with the pre-operative CT evaluation of regional lymphadenopathy in pancreato-biliary malignancies. Methods: Regional lymph nodes metastasis is a poor prognostic factor in pancreato-biliary malignancies. CT findings like lymph node size > 10mm, irregular shape, heterogenous enhancement, conglomeration and infiltration can suggest metastatic involvement. Cholangitis can induce reactive changes in regional lymph nodes. This study aimed to find if episodes of cholangitis interfere with the pre-operative CT evaluation of regional lymphadenopathy in pancreato-biliary malignancies. Results: A total of 41 patients of gallbladder cancer and 20 patients of periampullary cancer were included. A total of 206 lymph node stations were sampled. In gallbladder cancer group, CT finding of lymph node size > 10mm, ill-defined borders and conglomeration; while intra-operative findings were node size > 10mm, hard consistency and necrosis on cut-section significantly predicted metastatic lymphadenopathy on univariate analysis. In multivariate analysis, size > 10mm measured intra-operatively was the only significant predictor of metastatic lymphadenopathy.21.9% patients (9/41) had history of cholangitis pre-operatively. In this subgroup, none of the CT characteristic or intra-operative nodal feature significantly predicted malignant involvement. In periampullary cancer, nodal necrosis on intra-operative cut-section was a significant predictor of malignant involvement in univariate, but not in multivariate analysis. Subgroup analysis of patients with history of cholangitis (10/20) did not reveal any significant pre-operative or intra-operative lymph nodal feature predicting malignant involvement. Conclusions: In patients with gallbladder or periampullary cancer with history of cholangitis, the typical CT characteristics or the intra-operative characteristics of regional lymph nodes cannot be relied on to predict metastatic lymph node involvement. Thus, cholangitis affects the clinical staging of these malignancies.