Para-aortic lymph node metastasis in carcinoma of the head of the pancreas.
Metastasis to para-aortic lymph nodes often occurs in pancreatic head cancer, but factors that predict it are not well known. Using histopathologic data of 178 patients who underwent extended lymph node dissection for pancreatic head cancer, we analyzed the distribution of metastases to lymph node groups classified in detail and attempted to identify the lymph node groups that have a strong relation with metastasis to para-aortic lymph nodes. A high incidence of lymph node metastasis was found in para-aortic lymph nodes (No. 16, 19%) as well as in regional lymph nodes, such as those on the posterior aspect of the pancreas head (No. 13, 47%), on the anterior surface of the pancreas head (No. 17, 29%), along the superior mesenteric artery (No. 14, 28%), and along the hepatoduodenal ligament (No. 12, 19%). Statistical analysis showed that metastases to para-aortic lymph nodes had a strong correlation with metastases to Nos. 12, 13, 14, and 17 lymph nodes. Para-aortic lymph node metastases were seldom observed among the patients who had no metastases to Nos.13, 14, and 17 lymph nodes. Examination of Nos. 13, 14, and 17 lymph nodes may be useful to predict the involvement of para-aortic lymph nodes.