Sunday, February 9, 2014

Diseases of the Adrenal Glands

Diseases of the Adrenal Glands-


-Corticoadrenal Insufficiency-
-The symptoms of adrenal insufficiency depend on the amount of adrenal function loss and the rate of which it is lost
-common symptoms of adrenal insufficiency are malaise, lassitude, fatigue, generalized weakness, anorexia, abdominal pain, nausea, vomiting, diarrhea, and weight loss
-may have postural hypotension or syncope
-hyponatremia is common, hyperkalemia and hypoglycemia are common
-hyperpigmentation is seen in almost all patients
-decreased axillary and pubic hair loss, loss of libido are common in women.  Amenorrhea may be present
-may have psychosis, depression, impairment of memory, or mild organic brain syndrome

-can come from prolonged administration of glucocorticoids.  This is the most common causes of adrenal insufficiency

-initial workup should include CBC, Chem 7, ACTH, renin, cortisol, aldosterone
-ACTH stimulation test is good for helping establishing the diagnosis
-Abdominal CT scan may show enlarged adrenal glands or adrenal calcification

-causes of adrenal insufficiency include:  destruction of adrenal cortex (from autoimmune adrenalitis),  polyglandular autoimmune syndrome type 1 and 2, infectious, tuberculosis, fungal infections, HIV, hemorrhagic infarction of the adrenal gland, metastatic disease, and drugs


-Adrenal Insufficiency can come from 3 different mechanisms-

-Primary Adrenal Insufficiency (Addison's Disease)-an inadequate serum cortisol response to ACTH stimulation shows adrenal insufficiency but does not show if primary, secondary or tertiary.

-A Pituitary Disorder resulting from deficiency of ACTH

-A Hypothalamic Disorder resulting from CRH deficiency and leads to low ACTH


-Treatment of Chronic Primary Adrenal Insufficiency includes supplement of dexamethasone or prednisone, fludicortisone, liberal salt intake, androgen replacement and patient medication

-Fever should be examined for etiology and treated

-Adrenal crisis usually presents as shock.  Abdominal tenderness and fever may be present.  Fever would be do to infection and needs to be treated.

-Treatment of adrenal crisis includes IV fluids 1-3 liters of NS or D5 NS within the first 12-24 hours.  Hypotonic saline could make the hyponatremia worse
-Dexamethasone 4 mg IV should be given


-Cushing Syndrome-



-Cushing Syndrome may be either ACTH dependent or independent
-The most common cause of Cushing Syndrome is from administration of glucocorticoids

-If the cause is ACTH dependent will see adrenal cortical hyperplasia on imaging studies

-If the cause is ACTH independent, it is most commonly iatrogenic.  Can see it also from adrenal adenomas or carcinomas

-Most patients with Cushing Disease will have a pituitary adenoma

-There may be ectopic ACTH from benign neuroendocrine tumors (carcinoid) or from malignant sources like Oat Cell carcinoma

-There may ectopic CRH where the tumor causes hyperplasia and hypersecretion of pituitary corticotrophs

-To establish the diagnosis of Cushing Syndrome want to exclude the presence of exogenous steroid ingestion

-Patients with other disorders may have high cortisol levels and not have Cushing Syndrome, these disorders are:  physical stress, severe bacterial infection, severe obesity, polycystic ovarian syndrome, major depression, and chronic alcoholism.  These patients are sometimes referred to as having pseudo Cushing Syndrome.

-Need two first line tests to confirm the presence of Cushing Syndrome
-Should use late night salivary cortisol, urinary cortisol, and low dose dexamethasone suppression test as the first line tests
-urine and saliva cortisol tests should be obtained twice
-urine cortisol excretion should be 3 times the upper limit of normal to rule in Cushing Syndrome


-Treatment of Cushing Syndrome includes reveres clinical manifestations by normalizing cortisol levels, remove any tumors causing, avoid permanent dependence on medications, and avoid hormone deficiency

-Need to discontinue exogenous glucocorticoids
-Need to treat pituitary adenomas with transsphenoidal microadenomectomy
-Adrenal enzyme inhibitors can be used if surgery is delayed or contraindicated
-Pituitary irradiation can be done on patients where fertility is a concern
-Bilateral adrenalectomy with lifelong glucocorticoid and mineralocorticoid replacement is a final definitive cure
-Patients with ectopic ACTH or CRH syndromes the tumor should be removed
-Somatostatin Analogues rapidly reduces ACTH secretion by non pituitary tumors


-Neoplastic Disease-



-Unilateral tumors or masses of the Adrenal Gland are considered functional (hormone secreting) or silent
-Adrenal tumors are also classified as either benign or malignant
-Most adrenal tumors are benign, silent tumors known as adrenal incidentalomas
-There are other benign functional tumors that cause Cushing Syndrome, Primary Hyperadosteronism, and virlization
-Adrenocortical Carcinomas are aggressive tumors that can be functional and cause Cushing Syndrome or can be non functional and just present as an abdominal mass
-Pheochromocytomas are catecholamine producing tumors that arise from the adrenal medulla.  They can be benign or malignant.  They cause high blood pressure and catecholamine related physiologic changes

-Adrenocortical Adenomas are begin neoplasms that can secrete steroids independently from ACTH or the renin angiotensin mechanism

-Aldosteronemas are adrenal incidentalomas that can cause primary aldosteronism

-The maximum diameter is predictive of malignancy, most adrenal adenomas are less than 4 cm in diameter

1 comment: