Cushing’s Syndrome - The Diagnosis and Differential Diagnosis

The diagnosis and differential diagnosis of Cushing’s syndrome remains an on-going challenge in clinical endocrinology. Although the condition is considered rare, the clinical spectrum of the disease is broad, and its investigation is frequently required given the high prevalence of many of its non-specific symptoms such as central obesity, muscle weakness and depression. Clinicians are now considering the diagnosis in its earlier manifestations, often before the development of the more classic signs and symptoms as described by Harvey Cushing early in the last century. In its severe form and when untreated, the metabolic upset of Cushing’s syndrome is associated with a high mortality, approximately 50% at five years (1). However, more subtle excesses of cortisol may have significant effects on glycaemic control and blood pressure, and may therefore be an important cause of morbidity.