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 Gushing's syndrome due to metastatic hepatic carcinoid tumo ur from a probable pancreatic primary. Hypercortisolaemia was controlled wi th metyrapone and ketoconazole, but high doses of octreotide failed to affe ct plasma cortisol and urinary 5-hyroxyindole acetic acid (5HIAA) levels, o r prevent rapid tumour growth. Hepatic polystyrene embolisation failed, and she was treated by liver transplantation with initial excellent results, a nd normalisation of cortisol and 5HIAA levels. Ten months later, however, s he relapsed with bony and pelvic tumour recurrence, and high and symptomati c levels of cortisol and 5HIAA. At this time, octreotide in similar doses t o those used previously appeared to normalise her biochemically, although s he died soon after. This variable responsiveness to octreotide could be rel ated to somatostatin receptor changes, or cyclical tumour secretion pattern s.