Signet ring cell carcinoma of the lower bile duct with rapid growth: report of a case.

Signet ring cell carcinoma occurring in the biliary tract is extremely rare. We herein report the case of a 78-year-old Japanese woman demonstrating signet ring cell carcinoma of the lower bile duct with a rapid growth. Computed tomography of the pancreas head pointed out a circular thickness in the lower bile ductal wall and stenosis of the common bile duct.