A huge intraductal papillary mucinous carcinoma of the bile duct treated by right trisectionectomy with caudate lobectomy

Abstract

Background: Because intraductal papillary mucinous neoplasm of the bile duct (IPMN-B) is believed to show a better clinical course than non-papillary biliary neoplasms, it is important to make a precise diagnosis and to perform complete surgical resection.

Case presentation: We herein report a case of malignant IPMN-B treated by right trisectionectomy with caudate lobectomy and extrahepatic bile duct resection. Radiologic images showed marked dilatation of the left medial sectional bile duct (B4) resulting in a bulky cystic mass with multiple internal papillary projections. Duodenal endoscopic examination demonstrated very patulous ampullary orifice with mucin expulsion and endoscopic retrograde cholangiogram confirmed marked cystic dilatation of B4 with luminal filling defects. These findings suggested IPMN-B with malignancy potential. The functional volume of the left lateral section was estimated to be 45%. A planned extensive surgery was successfully performed. The remnant bile ducts were also dilated but had no macroscopic intraluminal tumorous lesion. The histopathological examination yielded the diagnosis of mucin-producing oncocytic intraductal papillary carcinoma of the bile duct with poorly differentiated carcinomas showing neuroendocrine differentiation. The tumor was 14.0 x 13.0 cm-sized and revealed no stromal invasiveness. Resection margins of the proximal bile duct and hepatic parenchyma were free of tumor cell. The patient showed no postoperative complication and was discharged on 10th postoperative date. He has been regularly followed at outpatient department with no evidence of recurrence.

Conclusion: Considering a favorable prognosis of IPMN-B compared to non-papillary biliary neoplasms, this tumor can be a good indication for aggressive surgical resection regardless of its tumor size.

Figure 1

Axial image of enhanced computed tomography shows a bulky cystic mass with multiple internal papillary projections involving the right hemiliver and left medial section (A). Magnetic resonance cholangiography (MRC) reveals a marked aneurysmal dilatation of the bile duct itself of the left medial section and a diffuse dilatation of the extrahepatic bile duct (B).

Figure 2

Duodenal endoscopy demonstrates mucin expulsion from the patulous ampullary orifice (A). The findings of endoscopic retrograde cholangiogram (ERC) are similar to those of MRC, but ERC additively shows amorphous intraluminal filling defects corresponding to mucin and papillary tumors within the dilated bile ducts (B).

Figure 3

The macroscopic appearance of the transected specimen (A) reveals a cystic dilatation of the intrahepatic bile ducts with intraluminal mucin and multiple papillary tumors. Arrows indicate a poorly differentiated carcinoma with neuroendocrine differentiation abutting on the main tumor. Histopathological examination (B) demonstrates papillary structures without stromal invasion (hematoxylin and eosin ×40). This oncocytic type papillary cholangiocarcinoma (C) shows a columnar lining with abundant oxyphilic granular cytoplasm with intraepithelial lumina, which gives rise to a cribriform pattern of growth (hematoxylin and eosin ×200).