BP is rare neoplasm first described by Caroli in 1959 . To date, there are fewer than 100 cases reported in the English literature. BP has a 2:1 male to female ratio, and mean age at presentation is the seventh decade of life (60 to 70 years of age). Initially, BP was thought to be a benign neoplasm associated with low malignant potential and an overproduction of mucin . However, recent studies are challenging this paradigm, noting that not all patients with BP have hypersecretion of mucin. In addition, malignant transformation rates are actually high, varying between 41% and 83% . Many patients with these benign premalignant papillary lesions of the biliary tract die from their disease.Patients typically present with symptoms of abdominal pain, jaundice, acute cholangitis or weight loss. In the review by Lee et al, BP subtypes were characterized based on mucin hypersecretion. Patients with mucin-secreting BP were more likely to present with cholangitis, and have marked dilation of the intra- and extrahepatic ducts, whereas the 40% without hypersecretion of mucin were asymptomatic. Preoperative imaging may include ultrasound, CT, ERCP, magnetic resonance cholangiopancreatography and/or cholan-gioscopy. Classic image features include dilation of the intrahepatic and extrahepatic bile ducts secondary to mucinous secretions. Extrusion of mucous from the ampulla of Vater may be seen during ERCP, similar to that seen in main duct intraductal papillary mucinous neoplasms. buy flovent inhaler
Characterizing papillomatosis are many foci of multicentric papillary fronds of the intra- and extrahepatic biliary columnar epithelium. The intrahepatic and/or extrahepatic biliary tree, including the gallbladder, can be variably involved. The papillary growth may be diffuse or confined to one segment. The distribution is approximately 40% to 45% intra-and extrahepatic biliary tree, 25% intrahepatic only, 25% extrahepatic only, and the remaining involving only the gallbladder. Histologically, papilloma or villous tumours show fibrovascular stalks with branching papillary fronds, lined by columnar-to-cuboidal epithelial cells with basal nuclei. In one series, the papillary tumours were lined with cellular atypia and intracytoplasmic mucin secretion. Recently, a collection of fine needle aspiration features have been described to help distinguish BP from cholangiocarcinoma. These included a hypercellular smear with double-cell layered sheets of ductal columnar epithelium, papillary configuration, preserved honeycomb pattern with equal nuclear spacing and dysplasia.