Image of the month: Diagnostic and therapeutic challenges in the management of ectopic ACTH syndrome: a perfect storm of hypercortisolism, hyperglycaemia and COVID-19.

Cushing's syndrome is a rare endocrine disorder requiring a high degree of clinical suspicion and meticulous investigations to diagnose and manage optimally. Delayed diagnosis and suboptimal treatment are associated with increased morbidity and mortality. Uncontrolled hypercortisolism leads to multiple cardiovascular and metabolic complications. Key risk factors identified for COVID-19-related adverse clinical outcomes (such as diabetes, hypertension and obesity) are, in fact, core clinical manifestations of Cushing's syndrome. Occurrence of SARS-CoV-2 infection in someone with uncontrolled hypercortisolism could, therefore, lead to disastrous medical consequences. We report a case highlighting challenges in the diagnosis and management of aggressive Cushing's syndrome secondary to ectopic adrenocorticotropic hormone (ACTH) secretion from an, as yet unidentified, neuroendocrine tumour. Our patient also contracted SARS-CoV-2 infection during investigations, which posed additional difficulties with aggravation of cardiometabolic complications. We also identify lack of clinical evidence to address management of this unique combination of two potentially life-threatening illnesses. © Royal College of Physicians 2021. All rights reserved.