Cushing's syndrome associated with a chemodectoma and a carcinoid tumour

We present a case of Cushing's syndrome where In-111-octreotide scanning pr ovided evidence for the presence of two neuroendocrine tumours. Uptake in t he right neck corresponded to a chemodectoma, but there was no change in th e clinical condition or fall in ACTH levels following surgical resection. U ptake in the left chest was assumed to relate to a bronchial carcinoid, but a tumour could not initially be localized on magnetic resonance imaging (M RI), spiral CT scanning or on selective venous sampling. A 1 cm bronchial carcinoid tumour was identified post-mortem which immunost ained for ACTH. This case demonstrates that (111)ln-octreotide scanning is a useful technique for identifying the source of ectopic ACTH production in difficult cases of Cushing's syndrome. Reliance should not be placed solel y on standard imaging techniques to localize the tumour prior to surgery. A lthough rare, the possibility of a non-ACTH secreting neuroendocrine tumour should also be considered in patients with ectopic ACTH syndrome, who have positive In-111-octreotide scans.