Introduction: Ectopic ACTH syndrome (EAS) is a rare condition, accounting for approximately 10% of all Cushings syndrome (CS). We assessed the experience managing this condition in our centre.
Methods: 171 patients (105 female, 66 male) with elevated plasma ACTH concentrations were identified from local IT systems at a tertiary centre (University Hospitals Birmingham NHS Foundation Trust) between 2002 and 2015. An electronic case note review was completed to exclude other diagnoses and 15 patients with a suspected diagnosis of EAS were identified. Data on demographics, clinical features, investigations, treatment, underlying diagnosis and outcomes were obtained.
Results: The underlying diagnosis was occult/unidentified in 4 cases, whilst 3 bronchial NETS, 1 pancreatic NET with liver metastases, 3 medullary thyroid cancers (1 with MEN2a), 1 metastatic adenocarcinoma of parotid, 1 metastatic lung cancer, 1 oropharyngeal tumour and 1 lung lesion with negative histology were identified. CT was the initial imaging modality in 13/15 patients, and was positive in 54% of cases. PET identified a bronchial NET in one patient. Octreotide scans were positive in 2/6 patients with negative CTs. 11/15 patients were treated with metyrapone and 7 of these required hydrocortisone replacement. 7/15 patients underwent surgical resection of the primary tumour whilst 5 patients proceeded to bilateral adrenalectomy. On final clinical follow up 79% achieved eucortisolism, whilst the remainder were on a metyrapone/hydrocortisone block and replace regimen. Median follow up was 52 months (IQR 1158). Mortality in the cohort was 33% (5/15), with death occurring in 3/4 patients with confirmed metastatic disease. All patients with occult disease were alive at final follow up.
Conclusion: EAS is caused by a diverse range of malignancies. PET and octreotide scanning may be of use in cases with negative cross-sectional imaging. Control of hypercortisolism was effective in our cohort. Occult disease was a positive prognostic finding.