Clinicopathological study on neural invasion to the extrapancreatic nerve plexus in pancreatic cancer.

Thirty-four cases that underwent resection of cancer of the pancreatic head were examined clinicopathologically to elucidate neural invasion of cancer of the pancreatic head into the extrapancreatic nerve plexus. Invasion of cancer into the retropancreatic tissue (rpe) was seen in 29 (86 per cent) of the 34 cases and neural invasion of the extra-pancreatic nerve plexus in 21 (72 per cent) of the 29 rpe cases. The incidence of invasion of the IInd portion of the nerve plexus of the pancreatic head was high (14 = 67 per cent). The degree of neural invasion tended to increase with the extent of lymph vessel invasion. Observation of serial sections revealed continuity of the neural invasion into the nerve plexus. From these findings we conclude that neural invasion of the extrapancreatic nerve plexus is mainly the result of continuous spread, and that en bloc resection of the retropancreatic tissue involving the nerve plexus and fat tissue is necessary in the surgical treatment of cancer of the pancreatic head.