Endocrine Abstracts

Case history: Ectopic adrenocorticotropic hormone (ACTH) production accounts for 10–20% of all endogeneous Cushing’s syndrome. The ideal treatment is curative surgery of the underlying tumour. In difficult cases bilateral adrenalectomy is an option. We report a 58-year-old woman with an aggressive ectopic Cushing’s syndrome that required bilateral adrenalectomy undertaken in 1989 at age 32-years.

Investigations: At 16 years post adrenalectomy, two right lung nodules became apparent on subsequent surveillance imaging. Over a 10-year period, these two foci on CT and Octreotide imaging demonstrated only marginal interval growth. The lung multidisciplinary team therefore advised against surgical intervention in 2006.

Results and treatment: However, in 2015, these two foci increased in size with growth noted in proximity to the main vessels and bronchi. She was therefore referred for surgery and underwent a right lung wedge resection. Histology was consistent with two bronchial typical carcinoids with clear resection margins and stained positive for ACTH. Post-operative imaging (CT chest, abdomen and pelvis, and gallium DOTATATE) demonstrated surgical lung changes, but no evidence of new or recurrent DOTATATE avid disease.

Conclusions and discussion: Since surgery, her tan significantly decreased. ACTH fell from a preoperative level of 1465 ng/l to 12 ng/l postoperatively with reduction in pigmentation, suggesting cure from ectopic ACTH-secretion. Ectopic ACTH-secreting tumours present challenges and require careful clinical, biochemical, radiological and pathological investigations. As this case demonstrates, ectopic ACTH-producing tumours can be extremely difficult to localise and often require multiple modalities of imaging. At present, there is no accepted frequency for imaging in occult ACTH-producing tumours. Our patient had an occult and indolent tumour that took almost two decades to present but has now had curative surgery.