Carcinomas of the ventral and dorsal pancreas exhibit different patterns of lymphatic spread

In patients with carcinoma of the head of the pancreas with positive lymph nodes, the extent of an adequate lymph node dissection beyond peripancreatic area has remained controversial. Based on the two anlagens, the ventral or dorsal pancreas, we assessed the lymphatic spread pattern in 58 primary adenocarcinoma of head of the pancreas. Detection of lymph node metastasis was based on microscopic detection of carcinoma in consecutive serial sections of resected specimens including lymph nodes. When the tumor was confined to the ventral pancreas domain (n=20), the lymph node metastases were limited to areas along the superior mesenteric artery (SMA) besides peripancreatic lymph nodes. When the tumor was in the dorsal pancreas domain (n=6), the lymph node metastases were limited to areas along the common hepatic artery (CHA) and the hepatoduodenal ligament besides peripancreatic lymph nodes. When the tumor was extended into both domains (n=32), the lymph node metastases were distributed widely in areas along the SMA, CHA and the hepatoduodenal ligament besides peripancreatic lymph nodes. Based on these findings, the lymphatic spread of carcinomas of the head of the pancreas can be divided into two patterns by tumor location based on the two anlagens of the pancreas.