Mineralocorticoids (aldosterone), glucocorticosteroids and sex hormones are formed in the adrenal cortex, and their secretion is controlled by the hormones of the anterior pituitary gland. Strengthening the tropic effects of the pituitary gland or the development of a hormonally active tumor of the adrenal cortex leads to their hyperfunction, and the weakening of these influences or destruction of the adrenal cortex leads to hypofunction. The secretion of the hormones of the adrenal medulla (adrenaline, norepinephrine) is stimulated by the sympathetic nervous system.
Addison’s disease (bronze disease) – a disease caused by the defeat of the predominantly cortical substance of the adrenal glands. At present, it is believed that autoimmune mechanisms are of primary importance in the development of Addison’s disease (up to 60% of all cases). This is confirmed by the discovery of antiadrenal autoantibodies, a frequent combination of Addison’s disease with other typical autoimmune diseases (thyroiditis, pernicious anemia). Previously, more than half of the cases of Addison’s disease were associated with tuberculous damage to the adrenal glands. Other causes of Addison’s disease include metastatic tumors, adrenal amyloidosis, hemorrhage, and arterial emboli.
In idiopathic Addison’s disease, the cortical substance of the adrenal glands loses its three-layer structure, the cells are preserved in the form of islets surrounded by fibrous tissue permeated with lymphoid cells. Clinical signs of the disease appear suddenly, when more than 90% of the bark of both glands are affected and the level of glucoproteins and mineralocorticoids is significantly reduced. Clinical manifestations: weakness, fatigue, nausea and vomiting, weight loss, hypotension, skin hyperpigmentation.
Secondary insufficiency of the adrenal cortex is caused by a decrease in the secretion of ACTH, which may be caused by hypothalamic dysfunction or previous corticosteroid therapy.
Acute adrenal insufficiency – adrenaline crisis (Waterhausen-Frideriksen syndrome) – a rapidly progressive state, clinically occurring in the form of shock. The cause of its development can be septicemia (especially meningococcemia), bacterial shock, rapidly progressing hypotension, asphyxia of the newborn, etc. Regardless of the cause, hemorrhage in the adrenal glands is morphologically observed.
Hyperfunction of the adrenal cortex. There are three main hyperadrenal syndrome: Cushing, Kona and adrenogenital.
ACTH-dependent Cushing’s syndrome develops with the administration of large doses of ACTH or its synthetic analogue (iatrogenic causes) or in connection with ACTH hypersecretion by the pituitary (corticotropic pituitary adenoma, – as a result, bilateral adrenal hyperplasia develops).
ACTH-independent Cushing’s syndrome develops in the presence of adrenal cortex tumors (adenoma, less commonly adenocarcinoma). Adenoma of the adrenal cortex is significantly more common in women.
Clinical manifestations of Cushing’s syndrome: upper type obesity (face and body), abdominal stretch marks, development of steroid diabetes mellitus and arterial hypertension, skin thinning, osteoporosis, immunological changes accompanied by an increased sensitivity of the body to infections.
Kona syndrome (primary aldosteronism) develops in 1/3 cases of hyperfunction of the adrenal cortex. In this disease, morphologically, adrenal cortex adenoma is found in patients. Microscopically, it is represented by light cells with lipid inclusions, which are similar to cells of the reticular zone of the adrenal glands. An increase in aldosterone production causes sodium retention, an increase in total blood plasma, arterial hypertension and inhibition of renin secretion.
Adrenogenital syndrome (AHS) develops with congenital adrenal hyperplasia caused by hyperproduction of ACTH. The leading link in the pathogenesis of this syndrome is a congenital violation of the synthesis of hydrocortisone. The syndrome is inherited in an autosomal recessive manner, with a population frequency of 1: 5,000 newborns; more often girls are sick. The lack of the final product of the synthesis of glucocorticoids stimulates the secretion of ACTH, which leads to hyperplasia of the adrenal cortex and hypersecretion of progenitor hormones. Clinical manifestations of AGS are associated with the virilizing effect of the resulting excess androgens, and in some cases other severe metabolic disorders and arterial hypertension.
The following clinical forms of AGS are distinguished: viril (simple), salt-losing, and hypertensive. Virilic form in girls is accompanied by false hermaphroditism (augmentation of the clitoris, augmentation and fusion of the labia majora, the absence of secondary sexual characteristics), excessive hair growth. Hyperglycemia, hyponatremia, hypochloremia and hyperkalemia, which are manifested by nausea, vomiting, and dehydration are characteristic of the loss-consuming form of AHS due to a deficiency of cortisol and aldosterone.
Hypertensive form of AHS occurs when there is an excess of desoxycorticosterone. Virilization is complemented by a steady increase in blood pressure, changes in the internal organs, typical of hypertension. The adrenal glands are hyperplastic, their mass reaches 60-80 grams, histologically the cells of the reticular zone are enlarged, with light vacuolation cytoplasm. The remaining zones of the cortex are intact or hypoplastic. In the solitary form, hypertrophy and hyperplasia of the cells of the juxtaglomerular apparatus of the kidneys, expansion of the mesangium of the renal glomeruli are noted.
Tumors of the adrenal glands. There are tumors of the adrenal cortex and tumors of the brain substance (tumors of chromaffin tissue).
In the cortex of the adrenal glands, benign adrenocortical adenomas are found. The following variants of adenomas are distinguished: clear cell and dark cell adenomas.
Clear cell adenoma is more often single, sometimes bilateral. Constructed from cells of various sizes, polygonal shapes, their cytoplasm contains neutral fat, cholesterol. Among the tumor cells, adipose and bone tissue with bone marrow elements can be found. The predominant clinical sign is hyper aldosteronism syndrome.
Dark-cell adenoma consists of small cells with eosinophilic compact or granular cytoplasm containing different amounts of lipofuscin and siderophilic granules (black adenoma). Clinically, this variant of adenoma has an androgenic or feminizing effect.
Malignant tumors – adrenocortical cancer. Macroscopically it is a knot, sometimes it can have a distinct capsule with areas of infiltrating growth. Microscopically, some cancers are built of light cells, others are represented by both light and dark cells, which are grouped into small and large cells with pronounced cellular atypism. Guitar cells with one or more malformed nuclei are typical. Metastases of adrenal carcinomas are predominantly hematogenous to the lungs, tumors tend to germinate into the veins. Since the tumor is hormonally active, hypercortisolism is clinically observed.
In the adrenal medulla, pheochromocytoma is most common in adults. Its name is explained by the ability of granules of cell secretion to turn brown in color with chromium salt solutions. Clinical manifestations of the tumor correspond to the effect of adrenaline and norepinephrine, which are determined by the tumor in the blood and urine in large quantities. Arterial hypertension of the permanent or paroxysmal type is characteristic. In 20% of cases, the pheochromocytoma is localized outside the adrenal glands, in the paraganglia in the anterior and posterior mediastinum, the gates of the kidneys, and the retroperitoneal tissue. Among the variants of the histological structure of pheochromocytoma, trabecular is isolated, when the tumor consists of trabeculae formed by large polygonal cells. The cytoplasm of cells contains a large number of brown-eosinophilic granules.The alveolar variant of the tumor is characterized by the formation of alveoli, constructed of large cells with vacuolated cytoplasm. In cells, catecholamine granules are detected.
Malignant pheochromocytoma, which is characterized by infiltrating growth, gives lymphogenous and hematogenous metastases, is extremely rare.
In children under the age of 1 year, the most common tumor of the adrenal medulla is neuroblastoma, which in this age group is the fourth among all tumors after leukemia, malignant lymphomas and brain tumors. In addition to the adrenal medulla, this tumor can be found in the cervical, thoracic, abdominal sympathetic ganglia. Histologically, the tumor is constructed from small cells with a large number of mitoses. The main importance in the diagnosis of such histological signs as the presence of neuropil and outlets. Neuroblastoma cells are immunoreactive to neuron-specific enolase, chromograninin and synaptophysin. Early neuroblastoma gives lymphogenous and hematogenous metastases.