Surgical anatomy

Clinically inapparent adrenal masses are discovered incidentally in the course of diagnostic testing for other conditions and, thus, are commonly termed incidentalomas. By definition, clinical signs or symptoms of such an adrenal tumor have to be absent.However, a substantial percentage of these incidentally detected adrenal tumors are hormonally active, with up to 20% of the tumors producing glucocorticoids (Fig. 1). Autonomous glucocorticoid production lacking specific signs and symptoms of Cushing's syndrome is termed subclinical or preclinical Cushing's syndrome (SCCS).Glucocorticoid production in these patients is low resulting in no or only mild symptoms which may not be clinically recognized as Cushing's syndrome (Fig. 2a). On the contrary,overt Cushing's syndrome,the consequence of longstanding excess of circulating glucocorticoids, is characterized by typical signs and symptoms of hypercortisolism like plethora, moon face, buffalo hump, central obesity, easy bruising, deeppurple striae, proximal muscle weakness, menstrual irregularities, acne, hirsutism, osteoporosis, and glucose intolerance (Fig. 2b). Classical Cushing's syndrome is a rare disease with an estimated incidence of 1:500,000 [34]. Pre-or subclinical Cushing's syndrome has become more recently the focus of a steadily increasing number of original reports and reviews [32]. Preclinical and subclinical Cushing's syndrome have often been used interchangeably in the literature. However, whereas subclinical Cushing's syndrome relates to a biochemical abnormality which most likely will not become clinically manifest,pre-clinical Cushing's syndrome implicates progression to overt Cushing's syndrome. Since progression to overt Cushing's syndrome occurs in a minority of patients, subclinical Cushing's syndrome better describes the metabolic consequences of this condition and will be used throughout this article.