ACTH-producing cholangiocarcinoma associated with Cushing's syndrome

A 61-year-old woman was admitted to the hospital with clinical manifestatio ns of Cushing's syndrome. The ACTH level was 1340 pg/mL, the urinary free c ortisol level > 900 mu g/mL, and the serum K+ levels 2.1 meq/L. The brain/p ituitary MRI and thoracic CT scan were normal. Gastroscopy, colonoscopy, an d small bower follow-through were normal. Abdominal CT and MRI showed norma l adrenals, but dilated gallbladder with numerous gallstones, as well as pe ripancreatic and hepatoduodenal lymphadenopathy. A large metastatic 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 lapa rotomy. Locally advanced cholangiocarcinoma was found, infiltrating the liver hilum , with multiple small bilateral liver metastatic deposits. Acute cholecysti tis 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 i mmunoreactive for ACTH. Small clusters of chromogranin A positive cells wer e also found to be immunoreactive for CRH, but not for ACTH.