Two cases of cholangiocarcinoma in diabetes mellitus causing worsening of glycemic control and acute liver dysfunction

This is a report of 2 cases of sudden and simultaneous worsening of glycemic control and acute liver dysfunction (biliary obstruction) suggestive of extrahepatic cholangiocarcinoma (ECC). Case 1 was a 59-year-old woman with a history of diabetes mellitus, hypertension, and hyperlipidemia who had adequate glycemic control for many years but developed worsening of glycemic control and liver dysfunction. Case 2 was a 68-year-old woman with a history of hypertension who developed worsening of glycemic control and liver dysfunction. Laboratory tests and ultrasonography revealed bile duct obstruction and computed tomography of the abdomen revealed distal common bile duct tumors in both cases. After tumor resection and pancreaticoduodenectomy, the pathological analysis revealed an adenocarcinoma in Case 1 and a rare collision cancer (adenocarcinoma and neuroendocrine carcinoma) in Case 2. These cases suggest that ECC should be suspected in patients who develop concomitant worsening of glycemic control and liver dysfunction and reiterate the need for careful clinical and radiological follow-up for the timely diagnosis and appropriate management of such rare neoplasms.