Disorders of adrenal function occur at all ages. Adrenal dysfunction may be an isolated problem or in conjunction with multiple organ involvement in certain syndromes. The chapter below details many aspects of the pathogenesis, diagnosis, and treatment of various forms of adrenal disease. Principles that are helpful in evaluating the most common pediatric clinical situations in which an adrenal disorder is suspected include:
- 1. Patients with early pubic hair development (premature pubarche) will have in order of frequency:
- a. Premature adrenarche
- b. Precocious puberty
- c. Late-onset congenital adrenal hyperplasia (CAH)
- d. Adrenal or gonadal tumor
- 2. Patients with "simple" obesity are distinguished from those with Cushing syndrome by the following clinical features:
- a. Cushing syndrome often develops rapidly
- b. Cushing syndrome patients do not grow well in height, but patients with obesity generally have accelerated height growth
- c. Cushing syndrome patients often have signs of androgen excess
- 3. Patients with adrenocortical insufficiency will have either:
- a. Primary adrenal failure, usually with symptoms of both glucocorticoid or mineralocorticoid (ie, salt loss) deficiency. Most commonly seen:
- i. Congenital adrenal hyperplasia (ambiguous genitalia in females)
- ii. Autoimmune Addison disease (often associated with other endocrinopathies)
- iii. Adrenoleukodystrophy
- b. Lack of adrenocorticotropic hormone (ACTH) stimulation of cortisol secretion, with symptoms of glucocorticoid deficiency alone. Most commonly seen:
- i. ACTH deficiency associated with multiple pituitary hormone deficiencies
- ii. Suppression of the hypothalamic-pituitary-adrenal axis because of recent discontinuation of corticosteroid treatment
The adrenal cortex secretes three classes of biologically active steroid hormones. These are glucocorticoids (cortisol), which are controlled by the hypothalamic-pituitary-adrenal axis; mineralocorticoids (aldosterone), which are controlled through the renin-angiotensin system; and androgens (dehydroepiandrosterone [DHEA] and androstenedione), which are controlled by an as yet uncharacterized trophic hormone.
Metabolic effects of steroid hormones are mediated by the interaction of each class of steroids with a specific cellular receptor. The ligand activated steroid-receptor complex dimerizes, enters the nucleus of target cells, and binds to various transcription factors. These form stable complexes at the site of a specific "steroid response elements." This bound complex then acts to modulate the transcription of specific target genes to exert the hormone effects.
The adrenal medulla secretes catecholamines, mainly epinephrine (adrenaline). Epinephrine secretion is stimulated by the sympathetic nervous system and by high cortisol levels from the adrenal cortex. The effects of epinephrine are mediated through adrenergic receptors, which produce tissue-specific effects.
The human adrenal gland is made up of two embryologically and functionally distinct endocrine organs, the adrenal cortex and the adrenal medulla. The adrenal glands lie at the upper pole of each kidney. Ectopic nodules (rests) of adrenocortical tissue may be located in the broad ligaments of the female or in the testes or spermatic cords of the male. The location of adrenal rests is determined by the location of the embryonic mesenchymal cells that develop into the adrenal cortex, gonad, kidney, ...