1. Endoscopic Retrograde Cholangiopancreatography Tissue Sampling: When and How? 
Georgios I. Papachristou, Thomas C. Smyrk, Todd H. Baron 
Clinical Gastroenterology and Hepatology 
Volume 5, Issue 7, Pages (July 2007)
DOI: /j.cgh
Copyright © 2007 AGA Institute Terms and Conditions

2. Figure 1
(A) Cholangiogram shows irregular distal bile duct stricture consistent with a malignant process. (B) Radiograph showing intraductal biopsy forceps passed into the bile duct and positioned just below the stricture. Note guidewire in place across the stricture allows the forceps to be passed alongside without need for biliary sphincterotomy.
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

3. Figure 2
Bile duct brushings, positive for malignant cells. The 3-dimensional structure of the group makes it impossible to focus on all cells at once. Note the extreme variation in nuclear volume at the upper left of the group (arrow). (Papanicolaou’s stain; original magnification, 60× objective).
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

4. Figure 3
Bile duct biopsy, positive for high-grade adenocarcinoma. The surface epithelium shows high-grade dysplasia (arrow), and the subepithelial space is filled with infiltrating carcinoma. (Hematoxylin-eosin stain; original magnification, 40× objective).
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

5. Figure 4
Benign bile duct brushings. Round, regular nuclei in a honeycomb arrangement. (Papanicolaou’s stain; original magnification, 60× objective).
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

6. Figure 5
Bile duct mucosa. The peribiliary glands are mucin rich and are arranged in a lobular group (arrow). (Hematoxylin-eosin stain; original magnification, 20× objective).
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

7. Figure 6
Adenocarcinoma in biliary mucosa. The subepithelial glands are haphazardly arranged (arrow), in contrast to the benign glands in Figure 5. (Hematoxylin-eosin stain; original magnification, 20× objective).
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

8. Figure 7
IgG4-associated cholangitis. The epithelium is benign. The subepithelial space has many plasma cells. The changes here are nonspecific, but immunohistochemical documentation of increased numbers of IgG4-positive cells would provide strong support for the diagnosis.
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions

9. Figure 8
Suggested diagnostic algorithm for pancreaticobiliary flow chart based on the results of cytology, FISH, and DIA in PSC and non-PSC patients. (Reproduced from Moreno-Luna et al, reference 26).
Clinical Gastroenterology and Hepatology 2007 5, DOI: ( /j.cgh )
Copyright © 2007 AGA Institute Terms and Conditions