Inverted urothelial papilloma (IUP) is a rare, non-invasive endophytic lesion that accounts for 1-2% of urothelial tumours. On cystoscopy, IUP appears as a pedunculated/papillary mass with a smooth surface. On microscopy, IUP has an endophytic growth pattern with the bulk of the tumour covered by a superficial layer of urothelium, which can be hyperplastic or attenuated. The cytology should be bland, with uniform, spindled cells arranged in anastomosing trabeculae and cords with peripheral palisading of basaloid cells. Exophytic papillae and mitotic activity should be absent or focal. Pseudoglandular spaces and squamous metaplasia may also be present. There are distinct molecular differences between IUP and urothelial carcinoma (UC). IUP rarely has mutations of FGFR3, homozygous loss of 9p21, or gain of chromosomes 3, 7, and 17, whereas these mutations are frequently seen in UC. In addition, IUP is much less likely to have TERT mutations compared to UC. Immunohistochemistry can also be helpful in distinguishing the two entities as IUP is typically negative for CK20 and has a low Ki-67 proliferation index. Positivity for p53 may be seen in a minority of IUP. IUP can recur and be seen in association with UC.Distinguishing IUP from UC can be difficult due to the similarity between the two entities both on cystoscopy and histology, as up to 25% of UCs will also have inverted growth. Given the morphologic variants of IUP and UC, it is possible for a diagnostic error to occur, which can significantly impact patient management.

Though variations of intrahepatic biliary anatomy are quite common, duplication of the extrahepatic biliary system is extremely rare and reported infrequently in the literature. Laparoscopic cholecystectomy is one of the most common general surgery procedures performed. Unfortunately, iatrogenic bile duct injuries can contribute to significant morbidity including hospital readmissions, infectious complications and death. Anomalous extrahepatic biliary anatomy may be one of the factors, which increases the likelihood of bile duct injury during laparoscopic cholecystectomy. We present a case of an iatrogenic bile duct injury that occurred during a laparoscopic cholecystectomy, in which a duplicated extrahepatic biliary system was identified intraoperatively during the definitive operative repair.

No abstract

No abstract

No abstract