Ectopic ACTH Production: Diagnosis, Treatment and Prognosis

Cushing’s syndrome due to ectopic ACTH as a result of metastatic malignancy invariably has a poor prognosis. In addition to tumour growth, diabetic and infective complications are causes of death. A multidisciplinary approach is needed with the focus of care being on management of endocrine abnormalities, control of symptoms and optimising quality of life. The adverse prognosis associated with these cancers should be taken into account when deciding on whether or not to pursue active oncological treatment with chemotherapy. In this case report, a 69-year-old patient presented with symptoms and signs of Cushing’s syndrome, which on further investigation was shown to be due to an ectopic ACTH-secreting metastatic small cell cancer of unknown primary. Treatment with palliative carboplatin etoposide chemotherapy and metyrapone was started, but unfortunately after one cycle of chemotherapy the patient died following hospital admission with poor diabetic control and non-neutropenic sepsis. We discuss the key issues in the diagnosis and management of this condition.