Endocrinology Flashcards
Where are glucocorticoid hormones produced?
Zona fasciculata of the adrenal gland.
What signwould you expect to be positive if your blood calcium level was 7.1 mg/dl?
trousseau’s sign
hypocalcemia
normal Ca: 8 - 10
Werner-Morrison syndrome is triggered by the production of:
Clinical manifestations of a vipoma (vasoactive intestinal peptide) can give rise to Werner-Morrison syndrome or pancreatic cholera, which causes excessive diarrhea, hypokalemia, and achlorhydria.
pioglitazone has been shown to be effective in preventing the progression and development of NAFLD in subjects with diabetes and pre-diabetes.
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The dawn phenomenon is
hyperglycemia in the early morning hours due to nocturnal secretion of GH during sleep.
Carla, 45 years old, undergoes a brain CT scan following a road accident. The examination reveals the presence of a pituitary incidentaloma. What is the most frequent histotype and what type of treatment is proposed in the first instance?
Prolactinoma is the most frequent histotype of pituitary adenoma and is the only one in which medical therapy with dopaminergic agonists is first proposed because the response to this treatment
What is Conn’s syndrome
a cause of primary hyperaldosteronism, is due to primary hyperproduction of aldosterone in the adrenal glands due to an adrenal adenoma.
Elevated aldosterone causes Na+ and water retention, and increased K+ excretion.
Renin is low in Conn’s syndrome due to the raised Na+ and plasma volume, both of which, when low, act as stimuli for renin secretion.
You would also expect the patient to be hypertensive. Note, however, that in this scenario, the patient is normokalaemic. This highlights the fact that > 20% of patients with hyperaldosteronism have normal potassium levels, so one should not rely on a low K+ for a diagnosis.
Addison’s disease results from adrenal gland failure and glucocorticoid and mineralocorticoid deficiency. This leads to Na+ loss and K+ retention.
Addison’s disease refers to adrenal insufficiency, commonly caused by autoimmune disease.
SX: weight loss, depression, anorexia, and gi upset.
Due to increased ACTH levels, patients have tanned skin and pigmented palmar creases. Investigations show hyponatremia, hyperkalemia, and hypoglycemia.
A short ACTH stimulation test confirms the diagnosis. Emergency treatment involves IV hydrocortisone and fluids with long-term management using oral cortisol and mineralocorticoids. Dose adjustments are based on individual needs, particularly during stress or illness.
What percentage of cases of phaeochromocytoma are due to a malignant cause?
Phaeochromocytomas are catecholamine-secreting tumours which, although rare, may cause life-threatening secondary hypertension. The tumour may be malignant in approximately 10% of cases.
The most frequent cause of primary hyperaldosteronism is
bilateral adrenal hyperplasia
Which of the following clinical signs of Cushing’s syndrome is not attributable to excess glucocorticoids?
Hyperpigmentation in Cushing’s syndrome is due to excess ACTH acting on MSH receptors
An excess of parathyroid hormone causes:
hypercalcemia
hypophosphatemia
In which of the listed pathologies do TARTs appear (Testicular adrenal rest tumors)
Adrenogenital syndrome
In patients with suspected acromegaly, serum IGF-1 concentration should be measured, not GH
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compared to GH, IGF-1 levels have fewer fluctuations and can be used to monitor the response to therapy. Usually basal GH levels are not used for diagnostics but the glucose load test (OGTT) is generally used
tumors of endocrine origin can manifest itself with the sudden appearance of increased hair in androgen-sensitive areas in a woman?
Adrenal carcinoma is a rare disease (incidence 0.7-2/million/year) with peak incidence between 40 and 60 years; in about half of the cases the tumor manifests itself clinically due to the presence of hormonal hypersecretion (70% cortisol/30% androgens); mass effect is the reason for presentation in most cases not associated with hormonal production
phaeochromocytoma, a neuroendocrine tumour that secretes adrenaline and noradrenaline, leading to sympathetic stimulation SX: tachycardia, HTN, anxiety, diaphoresis, and weight loss.
DX: elevated catecholamines and metanephrines in plasma or 24-hour urine.
Even though surgery is necessary, these patients are at high risk due to potential severe tachycardia and hypertension. Thus, sympathetic control through alpha-adrenoceptor blockers, such as phenoxybenzamine or doxazosin, is crucial. Isolated beta-blocker usage may result in refractory hypertension.
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What signalling pathway does growth hormone (GH) use?
A tyrosine kinase receptor that uses the JAK/STAT pathway
SIADH is a diagnosis of exclusion, so other causes of hyponatraemia, particularly diuretic therapy, adrenal failure and hypothyroidism, should be ruled out. However, in this patient, euvolaemia with hyponatraemia and low serum osmolality, combined with inappropriately concentrated urine (high urinary sodium and urine osmolality >100 mOsm/l), suggest SIADH.
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MEN 1
MEN 2A
MEN 2B
MEN 1 is associated with parathyroid, pancreatic, pancreatic, islet cell, and pituitary tumours. (Pituitary tumors, hyperparathyroidism and Zollinger-Ellison syndrome)
MEN 2a is characterised by thyroid medullary carcinoma, pheochromocytoma, and parathyroid tumours.
MEN 2b is associated with thyroid medullary carcinoma, pheochromocytoma, and mucocutaneous ganglioneuromas.
Pegvisomant is:
GH receptor antagonist. Pegvisomant is a growth hormone (GH) receptor antagonist and is used in the treatment of acromegaly.
In cases of primary hyperparathyroidism, the indications for surgery are the following: the finding of calcemia > 1mg/dl compared to the upper reference limit; the presence of osteoporosis, documented by a T-score < - 2.5 at the lumbar/femoral level; evidence of renal insufficiency, calciuria > 400mg/24h and age under 50 years. It is sufficient for only one condition to be met to indicate surgery. In the proposed case, although it is an asymptomatic disease, the young age of the patient and the finding of increased calciuria require parathyroidectomy (correct option D)
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his patient suffers from adult-onset diabetes in young people (MODY), which represents less than 5% of cases of diabetes mellitus and is linked to specific genetic defects that involve islet cells and are inherited in an autosomal dominant manner. In this patient with MODY 2 there is an inactivating mutation of glucokinase that increases the beta cell threshold for insulin release and the hyperglycemia is modest.
A young 25-year-old woman carries out a routine examination to check her health status. Her body mass index is 22. Laboratory studies show that her fasting blood sugar is 120 mg/dL. Urinalysis shows modest glycosuria, but no ketonuria or proteinuria. No autoantibodies to insulin are detectable. Her father presented the same symptoms at the age of 20. The gene coding for which of the following proteins is most likely to be mutated?
T/F DM does not cause gynecomastia
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Which of the following is the enzyme most frequently deficient in congenital adrenal hyperplasia?
21 hydroxylase deficiency