PMC4722727_01
Computed tomographic scan shows the presence of common bile duct-obstructing homogeneous mass (arrows). a Coronal view. b Axial view
13256_2015_789_Fig1_HTML.jpg
PMC4722727_01_13256_2015_789_Fig1_HTML.jpg
Fig1
On the basis of the tumor's radiological features, a preoperative diagnosis of extrahepatic bile duct malignant tumor was made (T1N0M0, type I, by Bismuth-Corlette classification) (Fig. 1).
Surgical-pathological findings of a tumor inside the bile duct. a Intact bile duct. b Dissected bile duct
13256_2015_789_Fig2_HTML.jpg
PMC4722727_01_13256_2015_789_Fig2_HTML.jpg
Fig2
The resection margin was 2 cm from one side and 2.5 cm from the other, and two investigated lymph nodes were identified as tumor-free (Fig. 2).
Microscopic examination (hematoxylin and eosin-stained slides). a General view of the tumor shows villous pattern of growth (original magnification, x6). b Cytological details of the tumor cells: slight nuclear atypia with no invasive growth (original magnification, x68). c Strong nuclear reaction with MSH2 immunomarker (original magnification, x98)
13256_2015_789_Fig3_HTML.jpg
PMC4722727_01_13256_2015_789_Fig3_HTML.jpg
Fig3
Histologically, the tumor consisted of branching papillary structures lined by tall columnar epithelium with slight nuclear atypia and scant fibrous stroma (Fig. 3a, b). PMS2, MSH2, and MSH6 proteins. Positive nuclear immunostaining was observed in tumor cells (Fig. 3c), which showed no evidence of microsatellite instability.