CT of neural plexus invasion in common bile duct carcinoma

Purpose: Our purpose was to analyze the CT findings of neural plexus invasion in common bile duct carcinoma. Method: We studied 16 patients with common bile duct carcinoma who underwent surgery. Of these, neural invasion was seen in 10 patients. CT findings were retrospectively reviewed and correlated with the surgical and pathological findings. Results: Irregular masses adjacent to the medial aspect of the uncinate process were observed in 4 of 14 patients with distal common bile duct carcinoma. These lesions extended medially and showed contiguity with the superior mesenteric artery and/or celiac axis, corresponding to neural plexus invasion with desmoplastic change. Increased attenuation of the fat between the common bile duct and the proper hepatic artery was seen in two of two patients with proximal common bile duct carcinoma, associated with neural plexus invasion in the hepatoduodenal ligament. Conclusion: The location and spread of neural plexus invasion in common bile duct carcinoma are characteristic and can be diagnosed by CT.