Adrenal Flashcards
(26 cards)
What are the symptoms and signs of excess cortisol?
Central obesity (Apple on a stick) Proximal muscle weakness Thin skin Easy bruising Osteoporosis/fragility fractures Moon face Supraclavicular fullness, Buffalo hump Violacious striae New or increasing hypertension Acne(only in disease)
How do we diagnose disorders of excess cortisol?
- Clinical diagnosis
- Confirm increased cortisol
- Determine acth dependant or independent
- Imaging
What zone produces aldosterone?
Zone Glomerulosa
What zone produces cortisol?
Zona fasiculata
What zone produces androgens?
Zona reticularis
What zone produces catecholamines?
Adrenal medulla
What mutation is present in congenital adrenal hyperplasia?
Mutations in CYP21B gene, which encodes enzyme 21 hydroxylase
Means problems converting progesterone precursors to deoxycortoisol products
Means low aldosterone and low cortisol
What are the classic findings of 21-OH deficiency?
No aldoSterone: low sodium, high potassium, acidosis, hypotension, high renin
No cortisol: failure to thrive, lethargic, hypoglycemia
High ACTH: pigmentation and enlarged adrenal vortices
Excess adrenal androgens: ambiguous genitalia in females precocious puberty in males
What increases ACTH secretion?
ADH
Stress
Gut hormones: CCK
Hypothalamus: CRH
What are the actions of glucocorticoids
Cardiovascular: increase cardiac output, increase peripheral vascular tone , “permissive”,
Skin: wound healing, collagen production
Metabolism: increase insulin resistance, adipocytes, decrease muscle protein synthesis
What are the normal patterns for glucocorticoid secretion?
Pulsating
Circadian rhythm
Negative feedback inhibits axis
What causes primary adrenal insufficiency?
- Autoimmune (addisons)
- TB
- Congenital hyperplasia
- X linked disease
Infiltration, drugs, etc
What are the cardinal features of primary adrenal insufficiency?
Hyperkalemia
Skin hyperpigmentation
Vitiligo (autoimmune)
Salt craving
What serious presentation happens in primary adrenal insufficiency?
Shock: usually mostly distributive but also hypovolemic and cardiogenic
What causes central or secondary adrenal insufficiency?
Rapidly stopping chronic prednisone treatment: body needs time to catch up again
Pituitary or hypothalamic disease
What is the ddx for an incidental adrenal mass?
Adrenal cortical tumors*: carcinoma, adenoma, nodular hyperplasia
Adrenal medullary tumors: pheochromocytoma
Cysts
Hematoma
Infection
Mets
What investigations should be done on an incidental adrenal mass?
History and physical for signs of endocrine derangements, mass effects
Labs: 24h urine metanephrines 24h urine cortisol, Dxm suppression test Aldosterone renin ratio Adrenal androgens
Imaging: CT
What features of an incidental adrenal mass indicate benign vs malignant?
Benign: less than 10 HU or 4cm, washout more than 50% at 10min
Malignant: more than 10 HU 04 6cm
What are the clinical features of primary aldosteronism?
Secondary cause of hypertension
Hypokalemia
Incidental adrenal mass
May be asymptomatic
How is primary aldosteronism investigated?
Screen with aldosterone renin ratio: >555
Diagnose with suppression test, either salt load or fludrocortisone
Look for underlying cause using CT! Adrenal vein sampling
What causes pheochromocytoma
Catecholamines secreting tumors in adrenal or sympathetic chain
May be associated with other diseases: neurofibromatosis, MEB2a/b, medullary thyroid cancer, Von hippel Lindau,
What are the cardinal symptoms of pheochromocytoma
Headache
Palpitations
Sweating
Happening in episodic spells and not necessarily at stressful times
What is the work up for pheochromocytoma
24h urine metanephrines and normetanephrines.
Plasma free metanephrines
CT/MRI for mass
What must be done before surgical resection of pheochromocytoma causing mass?
Rigorous blockade of catecholamines, otherwise can have huge surge
