Intraductal Papillary Biliary Neoplasm

Intraductal papillary neoplasm of the bile duct (IPNB) is a rare type of bile duct tumors characterized by a papillary growth found inside the bile duct lumen. It is regarded as a biliary counterpart of intraductal papillary mucinous neoplasm (IPMN) of the pancreas. IPNB displays a spectrum of premalignant lesion towards invasive bile duct cancer/cholangiocarcinoma. IPNB often spreads superficially along the bile duct mucosa (inner wall of the bile duct).

The prevalence of this disease shows a wide geographic variation. The highest incidence is found in the far Eastern countries, likely related to hepatolithiasis and liver fluke parasitic infection, which are believed to trigger the development of IPNB. IPNB is relatively uncommon, it is only about 9-38% of all bile duct cancer diagnosis. Most patients are between 50 and 70 years of age with slightly male predominance. The most common clinical presentations are intermittent jaundice (yellowing of the skin and eyes), cholangitis (biliary infection), and intermittent abdominal pain. Around 30% of patients are also found to have stones in their bile duct/ biliary tree. The most common radiologic findings are bile duct dilatation (patterns are diffuse duct ectasia, localized bile duct dilatation, and cystic dilatation) and findings of intraductal masses.

Ultrasonography, CT scan, MRI/MRCP, and video-endoscopic examination of the bile duct are usually obtained to assess tumor location and extension. Video-endoscopic/cholangioscopic biopsy can confirm the histology and assess the extent of tumor. Thick mucinous/gelatinous material can sometimes be found in the biliary duct. Microscopically, IPNB is composed of papillary fronds with hypervascular stalks. They look like a collection of fish eggs. Neoplastic cells range from mild dysplasia to invasive carcinoma involving the bile duct wall.

In order to choose an appropriate surgical procedure, an accurate preoperative assessment of tumor location and extension is crucial. The standard treatment for this disease is surgical resection of the involved biliary duct with or without corresponding liver resection, followed by complete resection of regional lymph nodes (lymphadenectomy). The treatment is essentially similar to that for bile duct cancer/cholangiocarcinoma. Intraoperative frozen section of the bile duct margins is necessary to confirm cancer-free surgical margins. Bile duct reconstruction with Roux-en-Y hepaticojejunostomy may or may not be necessary, depending on the location of the IPNB. The use of liver transplant surgery for this disease is very limited. Further research is needed to fully characterize the pathogenesis and prognosis of IPNB.

Bile duct excision/resection is best achieved through minimally invasive surgical technique. When compared to open operation, minimally invasive surgery leads to lower postoperative complication, less pain, less requirement for narcotics pain medication, and shorter recovery. Only very few liver and biliary surgeons in the United States perform minimally invasive bile duct resection. A high-volume bile duct surgeon or biliary center achieves superior outcomes when compared to a low-volume bile duct surgeon or biliary center.

Dr. Iswanto Sucandy offers minimally invasive bile duct resection/excision using the robotic technique. We have achieved significant experience in complex biliary tract surgery and liver surgery over the years. Our team work collaboratively with our interventional radiologists and interventional endoscopists to achieve the best long-term outcomes.