adrenals Flashcards
ACTH independent Cushing’s
- Adrenal adenoma or carcinoma
- Macronodular hyperplasia
- Primary pigmented nodular adrenal disease
- McCune‐Albright syndrome
ACTH dependent Cushings
ACTH dependent
– Cushing disease – pituitary adenoma
– Ectopic corticotropin syndrome (ACTH)
ACTH‐Secreting Pituitary Adenoma
ACTH‐Secreting Pituitary Adenoma
~70% of cases of endogenous hypercortisolism
W>M
Most frequently seen in young adults
Majority are microadenomas
Macroadenoma also possible
Rarely corticotroph cell hyperplasia without a discrete adenoma
- Primary
- Secondary from excessive stimulation from a hypothalamic corticotrophin‐releasing hormone (CRH)‐producing tumor
Secretion of Ectopic ACTH by Nonpituitary Tumors
•
Secretion of Ectopic ACTH by Nonpituitary Tumors
- ~10% of ACTH‐dependent Cushing syndrome
- Most often seen with small‐cell carcinoma of the lung
- Other neoplasms
- Carcinoids
- Medullary thyroid carcinoma
- Islet cell tumors
- Sometimes neuroendocrine neoplasm produces ectopic corticotrophin releasing hormone (CRH)
- → ACTH secretion and hypercortisolism
Primary Adrenal Neoplasms and Primary Cortical hyperplasia
-
Primary Adrenal Neoplasms
- Most common cause of ACTH‐independent Cushing syndrome
- Adrenal adenoma (~10%)
- Adrenalcarcinoma(~5%)
- Produce most profound hypercortisolism
- See ↑ cortisol and ↓ ACTH
-
Primary cortical hyperplasia
- Uncommon
- Vast majority of hyperplastic adrenals are ACTH dependent
Cushing Syndrome: Morphology of the Adrenal Gland
Cushing Syndrome Morphology of the Adrenal Glands
- Cortical atrophy
- Seen when exogenous glucocor coids → suppression of ACTH → lack of stimulation of the zonae fasciculata and reticularis
- Diffuse hyperplasia (both glands enlarged)
- Endogenous hypercortisolism
- ACTH‐dependent Cushing syndrome
- Cortex can be variably nodular
Macronodular hyperplasia
Macronodular hyperplasia
- Endogenous hypercortisolism
- Adrenals almost entirely replaced by prominent nodules of varying sizes (≤3 cm)
- Areas between the macroscopic nodules also demonstrate evidence of microscopic nodularity
Micronodular hyperplasia
Micronodular hyperplasia
- Endogenous hypercortisolism
- Composed of 1‐ to 3‐mm darkly pigmented (brown to black) micronodules, with atrophic intervening areas
- Pigment is thought to be lipofuscin
Primary Adrenocortical Neoplasms: classifications
Primary Adrenocortical Neoplasms
- Functional (Cushing syndrome) or non‐functional
- Morphologically indistinguishable
- Functional tumors: adjacent adrenal cortex and the contralateral adrenal gland are atrophic
- Yellow tumors surrounded by thin or well‐developed capsules
- Most weigh <30 gm
- Microscopically see cells that look like normal zona fasciculata
What tumor, and who is most likely to be seen with it?
Primary adrenal adenoma
- Most commonly seen in women aged 30‐50
- Adenomas (benign)
- Yellow tumors surrounded by thin or well‐developed capsules
- Most weigh<30 gm
- Microscopically see cells that look like normal zona fasciculata
primary adrenal neoplasms: adenoma vs carcinoma
functional/nonfunctional: Morphologically indistinguishable
Functional tumors: adjacent adrenal cortex and the contralateral adrenal gland are atrophic. Most commonly seen in women aged 30‐50
Adenomas (benign): Yellow tumor ssurrounded by thin or well‐developed capsules and most weigh<30 gm. Microscopically see cells that look like normal zona fasciculata
Carcinomas (malignant): Larger than the adenomas are usually > 200‐300 gm, Unencapsulated
Cushings clinical
- muscle: atrophy of what kind of muscle fibers?
- metabolism: what kind of profile?
- skin, immune system, bone
- Atrophy of fast‐twitch myofibers → decreased muscle mass and proximal limb weakness
- Glucorticoids induce gluconeogenesis and inhibit the uptake of glucose by cells
- Hyperglycemia, glucosuria and polydipsia (secondary diabetes)
- The catabolic effects → loss of collagen and resorp on of bones
- Skin is thin, fragile, and easily bruised
- Poor wound healing
- – Cutaneous striae are particularly common in the abdominal area
- – Osteoporosis
- Increased risk of infections (imm
Diagnosis of Cushing Syndrome (2)
- Diagnosis of Cushing Syndrome
- Increased 24‐hour urine free‐cortisol
- Loss of normal diurnal pattern of cortisol secretion
Determining the cause of Cushing Syndrome•
Determining the cause of Cushing Syndrome
- Serum ACTH
- Dexamethasone suppression test: Urinary excretion of 17‐hydroxycorticosteroids after administration of dexamethasone
identify the etiologies described in each column
- cushing’s disease (pituitary ACTH secreting microadenoma most common) (ACTH suppressed with high dose)
- Ectopic and adrenal tumor behave the same way to the dexamethasone test
Primary Hyperaldosteronism
Caused by
Mechanism
Primary Hyperaldosteronism
Caused by one of three mechanisms:
- Adrenocortical neoplasm
- Bilateral idiopathic hyperaldosteronism (IHA)
- Glucocorticoid‐remediable hyperaldosteronism
Autonomous overproduction of aldosterone
- Suppression of the renin‐angiotensin system and decreased plasma renin activity –> elevated BP is the most common manifestation
Adrenocrotical Adenoma: name, gender, age, lateral preferences
Adenoma: most common cause of hyperaldosteronism
- Called Conn Syndrome
- 30‐40 yrs most common
- W > M (2 : 1)
- Left > right
Usually solitary, Small (<2 cm in diameter), Well‐circumscribed lesions, Bright yellow grossly
Characteristic microscopic feature: spironolactone bodies
Adrenocortical adenoma: tumor in Conn’s syndrome
- Usually solitary
- Small (<2 cm in diameter)
- Well‐circumscribed lesions
- Bright yellow grossly
- Characteristic microscopic feature: spironolactone bodies
Bilateral Idiopathic Hyperaldosteronism
- Bilateral Idiopathic Hyperaldosteronism
- Most common cause of primary hyperaldosteronism
- Pts older
- Less severe hypertension
- Pathogenesis is unclear
- Bilateral nodular hyperplasia of the adrenal glands
Glucocorticoid‐Remediable Hyperaldosteronism
Glucocorticoid‐Remediable Hyperaldosteronism
- uncommon
- Familial hyperaldosteronism
- Rearrangement of chromosome 8 that places the gene for aldosterone synthase under the control of the ACTH responsive gene promoter
- ACTH stimulates the production of aldosterone
- Suppressible by dexamethasone
in addition to primary hyperaldosteronism, conn’s, and glucocorticoid remediable hyperaldosteronism, aldosterone released in response to activation of the renin‐angiotensin system by ↑ plasma renin is also seen in….
- Seen in:
- Decreased renal perfusion: arteriolar nephrosclerosis, renal artery stenosis
- Arterial hypovolemia and edema: congestive heart failure, cirrhosis, nephrotic syndrome
- Pregnancy: due to estrogen‐induced increases in plasma renin substrate
spironalactone bodies found in aldosterone secreting adenomas (conn’s). eiosinophilic, laminated cytoplasmic inclusions
Clinical Course of hyperaldosteronism
- Hypertension (most important)
- – ~5‐10% all hypertensive patients
- Clinical Course
- – ~20% of treatment resistant hypertensives
- – Most common cause of secondary hypertension (i.e.,an identifiable cause)
- Long‐term effects of hypertension on the CV system:
- – Left ventricular hypertrophy and reduced diastolic volumes
- – Stroke and myocardial infarction
- Aldosterone also promotes sodium reabsorp on → increased reabsorption of water
- – Expands the extracellular fluid volume
- – Elevated cardiac output
-
Hypokalemia (↓K) typically seen
- Weakness, paresthesias, visual dist
Screening and confirmation test and diagnosis of hyperaldosteronism
- Screening test:
- Elevated ratio of plasma aldosterone concentration to plasma renin activity
- Confirmation test:
- Aldosterone suppression test
- Administer: oral saline load, IV saline load, fludrocortisone
- If aldosterone is not suppressed: confirm primary hyperaldosteronism
tx for bilateral remediable hyperaldo and adenomas, secondary hyperaldo
- Varies depending on the cause
- Adenomas: surgical resection
- Treatment
-
Bilateral hyperplasia:
- Aldosterone antagonist (e.g. spironolactone)
-
Secondary hyperaldosteronism:
- Treat underlying cause
-
Bilateral hyperplasia:
Adrenogenital Syndromes
- Adrenogenital Syndromes
- Disorders of sexual differentiation: Virilization or feminization
- Primary gonadal disorders
- Primary adrenal disoders
- Disorders of sexual differentiation: Virilization or feminization
- ACTH regulates adrenal androgen formation:
- Adrenal cortex secretes dehydroepiandrosterone and androstenedione
- Converted to testosterone in peripheral tissues
- Adrenal cortex secretes dehydroepiandrosterone and androstenedione
- “Pure” syndrome or as a component of Cushing disease
- Adrenocortical neoplasms (more likely carcinoma)
- Congenital adrenal hyperplasia (CAH)
Congenital Adrenal Hyperplasia (CAH)
Congenital Adrenal Hyperplasia (CAH)
- Several autosomal‐recessive, inherited metabolic errors
- Deficiency or total lack of an enzyme involved in the biosynthesis of cortical steroids, esp. cortisol
21‐Hydroxylase Deficiency
- >90% of CAH
- Mutations of CYP21A2
- Three distinctive syndromes:
- Salt‐wasting syndrome
- Simple virilizing adrenogenital syndrome without salt wasting
- Nonclassic or late‐onset adrenal virilism
Salt‐Wasting Syndrome
- main problem
- typcially presents for boys/girls
- what it can cause
- Salt‐Wasting Syndrome
- Inability to convert progesterone into deoxycorticosterone
-
Typically presents soon after birth
- Virilization recognized in the female at birth or in uter
-
Males come to clinical attention 5‐15 days later because of some salt‐losing crisis
- Salt wasting (hyponatremia and hyperkalemia) → acidosis, hypotension, cardiovascular collapse, and possibly death
girls vs boys: salt wasting syndrome
- Inability to convert progesterone into deoxycorticosterone
- Typically presents soon after birth
- Virilization recognized in the female at birth or in uter
- Males come to clinical attention 5‐15 days later because of some salt‐losing crisis
- Salt wasting (hyponatremia and hyperkalemia) → acidosis, hypotension, cardiovascular collapse, and possibly death
progressive virilzation
- Simple Virilizing Adrenogenital Syndrome Without Salt Wasting
- Presents as genital ambiguity
- ~1/3 of 21‐hydroxylase deficiency
- Progressive virilization