Glandulae suprarenalis

The adrenal glands (suprarenal glandulae) are arranged in pairs. They lie retroperitoneally in the shape of a cap against the upper poles of the kidneys and are separated from these only by a delicate layer of fat. Like the kidneys, the left adrenal gland is about one vertebral body higher than the right adrenal gland (height BWK 12 versus 11). Kidney and adrenal gland are both enclosed by the fascia renalis (Gerota's fascia) and sheathed by the capsula adiposa. During embryonic development, the kidneys rise cranially toward the adrenals. Therefore, even in the presence of a pelvic kidney (e.g., in cachectic or anorectic patients), the adrenal glands are found unchanged in place high retroperitoneally. The adrenal glands are more intensely yellow and firmer than the surrounding adipose tissue.

The adrenal glands weigh about 3-6 grams (with a size of 5 × 2.5 × 1 cm). They produce a variety of hormones and are integrated into highly complex regulatory circuits and biochemical processes. Diseases of the adrenal glands can therefore cause the most severe systemic clinical pictures. A common clinical feature is often arterial hypertension. The left crescent-shaped adrenal gland is somewhat larger and heavier than the right more triangular-shaped one. The dorsal sides of both adrenals lie against the diaphragm. The facies anterior of the right adrenal nestles in the liver (impressio suprarenalis), likewise it is fused with the inferior vena cava in connective tissue. The facies anterior of the left adrenal gland adjoins the bursa omentalis and the upper margin of the tail of the pancreas. Of the right adrenal gland, only a small caudal portion is covered with peritoneum parietale; of the left adrenal gland, the entire anterior surface is covered. In the case of tumor formation, hormone excess can occur and, accordingly, very typical clinical clinical pictures.

Adrenal glands, hyperfunction syndromes

I Adrenal cortex

• Hyperaldosteronism (E27.4)
• Hypercortisolism (aldosteronismE24.9)
• Hyperandrogenism (adrenogenital syndrome - AGS E25.9)

II Adrenal medulla

• Catecholamine overproduction (pheochromocytoma D35.0)

I Adrenal cortex

Hyperaldosteronism

Primary hyperaldosteronism with decreased renin levels (Conn syndrome)

Familial hyperaldosteronism

• Type I (FHI): glucocorticoid-suppressible hyperaldosteronism (GSH)
• Type II (FHII): clinical adenoma or hyperplasia of the NNR
• TypeIII (FHIII): mutation of the potassium channel gene KCNJ5 (glucocorticoid-suppressible paradoxical increase of aldosterone after saline loading)

Aldosterone-producing carcinomas (note: rarity; 45% of adrenocortical carcinomas glucocorticoids, 31% androgens, and only 12% aldosterone).

Secondary hyperaldosteronism with elevated renin levels (e.g., in heart failure, liver cirrhosis, renal artery stenosis, therapy with diuretics).

Hypercortisolism (Cushing's syndrome).

Exogenous (iatrogenic ) Cushing's syndrome

Endogenous Cushing's syndrome (rare)

ACTH-dependent form with secondary NNR hyperplasia

• central Cushing's syndrome, causative = microadenomas of the anterior pituitary (Cushing's disease)
• Ectopic (paraneoplastic)ACTH secretion (secretion of ACTH in tumors, e.g. small cell lung carcinoma)
• Ectopic CRH secretion
• Alcohol-induced Cushing's syndrome

ACTH-independent primary form

• Cortisoproducing NNR tumors
• Micronodular dysplasia (rare)
• Macronodular hyperplasia (possibly ARMC5 mutation)

Hyperandrogenism

Adrenogenital syndrome - AGS - 21-hydroxylase defect (E25.9)

Simple-Virilizing Form (virilization only)

Salt-wasting Form (AGS with salt-wasting syndrome)

Rare Causes:

• 11ß-hydroxylase defect (rare).
• 17alpha-hydroxylase defect (rare)
• 3ß-hydroxsteroid dehydrogenase defect (rare)

Adrenal glands, hypofunction syndromes

Hypoaldosteronism (E27.4)

Primary hypoaldosteronism with elevated renin levels (Addison's disease)

Secondary hypoaldosteronism with decreased renin level (hyporeninemic hypoaldosteronism = renal tubular acidosis type IV)

Secondary hypoaldosteronism with increased renin level

Hypocortisolism (adrenocortical insufficiency- NNRI E27.4)

Primary adrenocortical insufficiency (pNNRI) = Addison' s disease (cessation of all corticosteroids)

Secondary adrenocortical insufficiency (sNNRI) = insufficiency of HVL or hypothalamus. Aldosterone production only slightly affected

Long-term treatment with corticosteroids(common).

_______________________________________________________________________________________________

II Adrenal medulla

Catecholamine overproduction (pheochromocytoma D35.0/paragangliomas)

The leading symptom of adrenal disease, whether cortex or medulla is the cause, can be arterial hypertension, although only about 2% of cases of hypertension are caused by the adrenal glands.

For the clarification of adrenal diseases, the collection of the following laboratory parameters is of particular importance:

• Serum electrolytes
• Blood count
• BSG
• renal retention parameters and hormone determinations (plasma, urine, 24-hour urine, saliva).

Note: The laboratory analytical methods must be applied very correctly - for example, at rest, with the patient lying down, standing up or after physical activity. The time of laboratory sampling can also be very important for hormone determinations with circadian rhythms. Medications may need to be paused.

Special tests are:

• the saline load test (infusion of 2000 ml of 0.9-percent NaCl solution over 4 hours before blood sampling)
• the dexamethasone inhibition test (oral administration of 1 mg dexamethasone at midnight, 8 o'clock plasma cortisol determination)
• the CRH test (CRH administration)

In primary adrenal malignancies, perioperative staging of the thorax, abdomen and skull must be performed.

Sonography, CT, MRI: Sonography, duplex sonography, CT native and with contrast enhancement, PET-CT (e.g. 18F-FDG-PET) or MRI (gadolinium, chemical shift technique) are used as technical examinations. MRI has gained strong importance today, as patients are often young or diagnostics even have to be performed under pregnancy.

Scintigraphy: MIBG, 131I-6BetaIodomethyl-Norcholesterol, 131I-19-Iodocholesterol, 75SeSelenocholesterol, Somatostatin receptor. These methods can be used to differentiate between hormone-active adenoma and hyperplasia.