[Perineural invasion of pancreas head carcinoma]

Perineural invasion of carcinoma is of considerable interest especially in the pancreas, because this organ is adjacent to the main autonomic plexuses of the abdomen. The present study was based upon 14 cases of primary carcinoma of the pancreas head in which total pancreatectomy with extensive dissection of the regional lymph nodes and autonomic plexuses was performed. Information concerning perineural invasion was obtained from histological specimens of the pancreas, lymph nodes and autonomic plexuses. Carcinomatous involvement of nerves was observed in all 14 cases within parenchyma of the pancreas head, but never found in the body and tail. Perineural extension of carcinoma to the regional autonomic plexuses was observed in 9 cases, which included the pancreatic capital plexus in 8 patients, superior mesenteric plexus in 3, celiac plexus in 2 and plexus on the common bile duct in 2 patients. This manner of invasion had no relationship with behaviour of lymph node metastasis. Thus, invasion and extension along the autonomic nerves by carcinoma of the pancreas were more common than usually recognized. Extensive dissection of the regional autonomic plexuses should be performed to increase the possibilities of a curative procedure.