Intraductal papillary neoplasm of the biliary tract with typical clinicopathological, endoscopic features: A case report.

BackgroundA literature review revealed that intraductal papillary mucinous neoplasm of the biliary tract (IPMN-B) cases with characteristic clinical, imaging, endoscopic, and pathological features are exceedingly rare. Herein, we present a case of typical IPMN-B with malignant transformation that required 4 years for a definitive diagnosis, to enhance the understanding of this disease entity.Case summaryA 67-year-old male patient was referred to our hospital due to abdominal pain and jaundice. Four years before this admission, a cystic lesion and left hepatolithiasis were incidentally discovered. Laboratory tests revealed mild increases in serum white blood cell count, total bilirubin, alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase. Tumour marker levels were within normal limits. Imaging findings demonstrated an enlargement of the cystic tumour from 41 mm to 63 mm, along with the development of numerous enhancing papillary nodules within it, which showed hyperenhancement during the arterial phase. Duodenoscopy revealed an enlarged major duodenal papilla with a fish-mouth appearance and dilated orifice, exuding translucent jelly-like mucus. Endoscopic retrograde cholangiography demonstrated multiple cloudy, irregular filling defects within the dilated extrahepatic bile duct. Following the diagnosis of IPMN-B, left hepatectomy was performed. Postoperative histopathological examination and immunohistochemistry confirmed IPMN-B with high-grade intraepithelial neoplasia and associated invasive carcinoma.ConclusionHeightened vigilance and recognition of IPMN-B are essential when "hepatic cysts" or "biliary stones" are incidentally detected.