ACTH-Producing Cholangiocarcinoma Associated with Cushing's Syndrome.

A 61-year~old woman was admitted to the hospital with clinical manifestations of Cushing's syndrome. The ACTH level was 1340 pglmL, the urinary free cortisol level > 900 pg/mL, and the serum K+ levels 21 meqlL. The brain/pituitary MRI and thoracic CT scan were normal. Gastroscopy, colonoscopy, and small bowel follow through were normal. Abdominal CT and MRI showed normal adrenals, but dilated gallbladder with numerous gallstones, as well as peripancreatic and hepatoduodenal lymphadenopathy. A large meta-static deposit and three smaller lesions were also seen in the liver. Because of the poor respiratory function tests and the severe hypokalaemia, laparoscopy under local anaesthesia was performed. Following the procedure the patient became gradually jaundiced and thus underwent exploratory laparotomy. Locally advanced cholangiocarcinoma was found, infiltrating the liver hilum, with multiple small bilateral liver metastatic deposits. Acute cholecystitis with pericholecystic abscess was also found. Cholecystostomy as well as gallbladder, liver and hilar node biopsies were performed. Histopathology showed liver adenocarcinoma of bile duct origin, while immunocytochemistry revealed scattered, chromogranin A positive cells, some of them strongly immunoreactive for ACTH. Small clusters of chromogranin A positive cells were also found to be immunoreactive for CRH, but not for ACTH.