Hematogenous metastases of pancreatic ductal carcinoma

To investigate the heterogeneity of hematogenous metastases of pancreatic ductal carcinoma, we investigated carcinomatous spread in 130 autopsy cases. Hepatic metastases occurred most frequently, in 81 cases (62%), which may be explained by the fact that all veins draining the pancreas flow into the portal system. We closely examined the 49 cases without hepatic metastases. Sixteen patients had pulmonary metastases without hepatic metastases, whereas seven had peculiar hematogenous metastases without hepatic or pulmonary metastases. Fifteen of these 23 patients had pancreatic body carcinomas. The unusual patterns of spread might be due to (a) hepatofugal portosystemic shunting induced by splenic vein obstruction, (b) retrograde lymphatic infiltration from metastatic tracheobronchial lymph nodes, or (c) aggressive characteristics of the tumors indicated by peculiar histologic features such as pleomorphic or mucoepidermoid carcinoma, etc. Sixteen patients showed only lymph node metastases and 10 had no distant metastases. Seventeen of these 26 cases had pancreatic head carcinoma. Histologically, two patients had mucinous cystadenocarcinomas, and six had adenocarcinomas producing rich mucin. The average age of the group with no distant metastases was higher.