Incidental high-grade dysplasia of the cystic duct margin: case report and literature review.

High-grade dysplasia (HGD) of the gallbladder has been proven to be an intermediate step in the pathogenesis from normal mucosa to invasive carcinoma. There is paucity of definitive data concerning the associated risk and optimal management of isolated HGD of the gallbladder involving the cystic duct margin following cholecystectomy. A previously healthy 44-year-old man underwent laparoscopic cholecystectomy for suspected symptomatic gallstones. The gross examination of the gallbladder did not show any discrete masses or lesions, and histopathologic evaluation revealed several proximal foci of HGD with involvement of the cystic duct margin. Subsequent magnetic resonance cholangiopancreatography (MRCP) showed central intra-hepatic ductal dilation, likely post-operative, with no evidence of malignancy. Patient underwent additional surgical exploration with laparoscopic excision of the cystic duct stump and intra-operative cholangiogram. The additionally resected stump showed mild chronic inflammation and reparative fibrosis without dysplasia. A follow-up MRCP two years later showed regression of the previously described dilation and no new lesions were detected. The patient remains disease-free until the present date. Isolated HGD of the gallbladder is an uncommon occurrence but can rarely involve the cystic duct margin. These patients are to be thoroughly investigated for associated carcinoma in other parts of the gallbladder. Additional studies are needed to better understand the long-term risk associated with premalignant lesions of the gallbladder to achieve optimal care and outcome for these patients.