What is ectopic ACTH producing cells?
Ectopic means that something is occurring in an abnormal place in the body. Ectopic Cushing syndrome is caused by tumors that release ACTH. Tumors that can, in rare cases, release ACTH include: Benign carcinoid tumors of the lung. Islet cell tumors of the pancreas.
How is ectopic ACTH treated?
Tumor excision is the primary treatment for EAS. However, when surgery is impossible, medical therapy is needed to treat hypercortisolism. The spectrum of available drugs includes adrenal-blocking agents, neuromodulatory drugs, and glucocorticoid receptor antagonists (7).
What is Nelson syndrome?
Nelson syndrome is a disorder characterized by abnormal hormone secretion, enlargement of the pituitary gland (hypophysis), and the development of large and invasive growths known as adenomas. It occurs in an estimated 15 to 25 percent of people who undergo surgical removal of the adrenal glands for Cushing disease.
How is ectopic ACTH diagnosed?
Ectopic ACTH secretion typically results from an occult, slow-growing bronchial carcinoid tumor. The diagnosis of these relatively small tumors can be difficult with conventional imaging procedures, such as computerized tomography (CT) or magnetic resonance imaging (MRI) (2).
Does ectopic ACTH cause hyperpigmentation?
Hyperpigmentation is a frequently reported manifestation of the ectopic ACTH syndrome. Awareness of this sign of elevated ACTH levels can guide diagnosis and management.
What is the best way to differentiate Cushing’s syndrome from ectopic ACTH tumor?
Inferior petrosal sinus sampling (IPSS) is the preferred test to differentiate Cushing’s disease from EAS. IPSS is based on the premise that a gradient of ACTH levels will exist as one samples venous blood further from the ACTH source.
What is ectopic CRH syndrome?
With ectopic CRH syndrome, it is assumed that the pituitary is the source of ACTH with secretion driven by CRH overproduction. However, these tumors have behavior distinct from pituitary corticotroph adenomas, and the majority appears to lack suppression with high dose dexamethasone.
How is Sheehan Syndrome diagnosed?
The gold standard imaging for the diagnosis of Sheehan’s Syndrome is MRI. The pituitary gland is housed in the sella turcica, which is a groove in the sphenoid bone. Pituitary gland necrosis empties the sella turcica. Imaging can reveal partial or full loss of the gland.
Why is ACTH high in Addison’s?
CRH stimulates ACTH release from the pituitary. In primary adrenal insufficiency, a high ACTH level is present, which rises further after CRH stimulation but unable to stimulate serum cortisol secretion.
Is ACTH high in Addison’s disease?
ACTH levels often are elevated to higher than 250 pg/mL in patients with Addison disease.