Carcinoid-associated ectopic ACTH syndrome with variable response to octreotide

The case is presented of a 31-year-old woman who developed florid clinical and biochemical Cushing's syndrome due to metastatic hepatic carcinoid tumour from a probable pancreatic primary. Hypercortisolaemia was controlled with metyrapone and ketoconazole, but high doses of octreotide failed to affect plasma cortisol and urinary 5-hydroxyindole acetic acid (5HIAA) levels, or prevent rapid tumour growth. Hepatic polystyrene embolisation failed, and she was treated by liver transplantation with initial excellent results, and normalisation of cortisol and 5HIAA levels. Ten months later, however, she relapsed with bony and pelvic tumour recurrence, and high and symptomatic levels of cortisol and 5HIAA. At this time, octreotide in similar doses to those used previously appeared to normalise her biochemically, although she died soon after. This variable responsiveness to octreotide could be related to somatostatin receptor changes, or cyclical tumour secretion patterns.