Endocrine Abstracts

Introduction: Cushing’s syndrome is caused by an extended exposure to increased levels of endogenous or exogenous glucocorticoids. It is a syndrome that can be extremely challenging to diagnose as many symptoms and signs are also indications of other disease processes.

Case: A 76 year old man presented to hospital with a six month history of immobility and falls. Proximal muscle weakness was also noted. The patient then underwent a period of rehabilitation.

The patient had a history of type 2 diabetes mellitus, hypertension, congestive cardiac failure, combined B12 and folate deficiency, longterm suprapubic catheter due to urinary retention, urinary tract infections and a myocardial infarction.

A first set of investigations revealed a 24 hr urinary free cortisol of 206 nmol/24 hr (0–146/24 hr), an overnight dexamethasone suppression test of 1588 nmol/L and a low dose dexamethasone suppression test of 1131 nmol/L (<50 nmol/L). The ACTH level was revealed to be 139 pmol/L and an MRI scan revealed a left-sided pituitary adenoma. As such, a diagnosis of ACTH-dependent Cushing’s disease was made.

The patient was initially managed with metyrapone with a view to transphenoidal surgery. However the patient developed shortness of breath and worsening peripheral oedema. A chest X ray and echocardiogram revealed left ventricular failure and reduced systolic function, respectively. For this reason it was decided to medically optimize his congestive cardiac failure and hypercortisolaemia as an inpatient with progression to neurosurgery if he were to stabilize.

Discussion: Cushing’s disease is a rarity that can be difficult to diagnose due to the significant number of varied pathologies indicated by its signs and symptoms. This is an interesting case of Cushing’s disease as the levels of cortisol measured in the patient were incredibly high.