DIT Endocrine Questions Flashcards
A 50 year ld female complains of double vision amenorrhea, and headaches. What is the most likely diagnosis?
Prolactin secreting adenoma of the pituitary (prolactinoma compressing optic chiasm)
A patients MRI reveals replacement tissue in the sella turcica with CSF. What is the most likely clinical presentation
Usually it is subclinical because although the pituitary appears to be missing, there is enough pituitary tissue lining the sella tursica such that there are no symptoms. However, sometimes a pituitary hormone may be deficient.
What hormones arise from the anterior pituitary?
FLAT PiG FSH LH ACTH TSH Prolactin GH MSH
What hormones share a common alpha subunit?
beta hCG = a (alpha) Terrible Fucking Life beta hCG TSH FSH LH
What are the main causes of pancreatitis?
Alcohol and gallstones, but if it isnt matching these two things think about hypertriglyceridemia and hyperparathyroidism.
Signs and symptoms of primary hyperPTH
Stones, Bones, Psychic moans, Abdominal groans, other
Stones- renal stones, nephrocalcinosis, polyuria/ polydipsia, uremia
Bones- Osteitis fibrosa, osteoporosis, osteomalacia, rickets, osteoarthritis
Abdominal groans- constipation, indigestion, N/v, Peptic ulcer, pancreatitis (elevated PTH raises gastrin levels)
Psychic moans- lethargy, fatigue, depression, memory loss, psychosis (paranoia), personality changes, confusion, stupor, coma
Other- proximal muscle weakness, keratitis, conjunctivitis, hypertension, itching
What account for 90% of the causes of hypercalcemia?
Primary hyperPTH (Solitary parathyroid adenoma» parathyroid hyperplasia)
Malignancy (produce local osteolytic factors (PTHrP) -> Sq. cell lung CA, renal CA, head and neck CA, T cell leukemia (HTLV-1) and breast cancer)
Malignancy (local invasion -> multiple myeloma and breast cancer)
What are the functions of Vit D?
- Increase absorption of Ca++ and Phosphate from the small intestine
- Increase bone resorption of Ca++ and Phos
How does PTH affect calcium? How does PTH affect phosphate?
PTH rids the bones of phosphate and calcium, but causes increased reabsorption of calcium from the kidney @ distal convoluted tubule and increased excretion of phosphate from the kidney (phosphate trashing hormone). Ultimately this raises serum calcium levels and lowers serum phosphate levels
What cells secrete calcitonin?
Parafollicular cells (C cells) of the thyroid -> neural crest
What are the two signs of hypocalcemia?
Chvostek (tap the Cheek) and Trousseaus (Tighten the cuff) signs
What are the two most common causes of hypercalcemia?
Primary hyperPTH (parathyroid adenoma > parathyroid hyperplasia) > Malignancy
What is the underlying cause of renal osteodystrophy? How will serum Ca, Phos, Alk Phos, and PTH levels compare to normal levels with this disease?
Renal osteodystrophy is bone lesions due to chronic renal disease. In renal disease there is nephron loss and an inability to activate vitamin D. Lack of vit D causes hypocalcemia and inability of the kidney to excrete phosphate leads to hyperphosatemia (phos binds free Ca++ contributing the hypocalcemia). This causes massive PTH secretion and bone resportion leading to osteodystrophy.
Levels- low 1, 25 (OH)2 Vit D, low Ca++, high Phos, high PTH, normal or high alk phos
What agents can be used to treat osteoporosis?
Calcium, phosphate, exercise, bisphosphonates, teriparatide (PTH analog that when given intermittently increases bone formation), calcitonin, gonadotropin, estrogens in women, raloxifene, tamoxifen, testosterone iin males. BISPHOSPHONATES ARE THE MAINSTAY!
What hormones work via intrinsic tyrosine kinases (MAP kinase pathway)?
Think insulin and growth factors.
- PDGF, FGF, EGF, IGF-1, insulin
What hormones work via receptor associated tyrosine kinase (JAK/STAT pathway)?
PIG
Prolactin, Immunomodulators (cytokines), GH
What cancers are associated w/ hypercalcemia?
Sq. cell cancer of any location, renal cell carcinoma, multiple myeloma, breast mets, sm. cell lung cancer
A young woman is found to have short stature and shortened 4th and 5th metacarpals. What endocrine disorder is most likely responsible for these manifestations?
Albrights hereditary osteodystrophy -> kidney unresponsiveness to PTH (pseudohypoparathyroidism). This is due to a mutation in the Gs protein of renal tubule cells.
What are some possible causes of hypoPTH?
Accidental surgical excision, autoimmune disease, Di George syndrome (failure to develop 3rd or 4th pharyngeal pouch -> where the parathyroids come from)
What is the most probable cause: hyperthyroidism + extremely tender thyroid gland
Subacute, de Quervains, granulomatous thyroiditis (de Quervain causes pain)
What is the most probable cause: hyperthyroidism + pretibial myxedema
Graves disease
What is the most probable cause: hyperthyroidism + pride in recent weight loss, medical professional
Levothyroxine abuse
What is the most probable cause: hyperthyroidism + palpation of single thyroid nodule
Toxic thyroid adenoma
What is the most probable cause: hyperthyroidism + palpation of multiple thyroid nodules
Toxic multinodular goiter
What is the most probable cause: hyperthyroidism + recent study using IV contrast dye (iodine)
Jod-Basedow phenomenon
What is the most probable cause: hyperthyroidism + eye changes -> proptosis, edema, injection
Graves disease
What is the most probable cause: hyperthyroidism + history of thyroidectomy or radio-ablation of the thyroid
too high of dose of levothyroxine
A 35 year old female presents with diffuse goiter and hyperthyroidism. What are the most likely relative values of TSH and thyroid hormone?
This is most likely to be graves disease and therefore the thyroid hormones will be high due to TSI (IgG) but negative feedback by T3 will cause TSH to be low
A 48 year old female has been suffering with progressive lethargy and extreme sensitivity to cold temperatures. What is the most likely diagnosis.
hypothyroidism, hashimotos is most common
Most common type of thyroid cancer (70-75%)
Papillary carcinoma
Second most common type of thyroid cancer (10%)
Follicular
Thyroid cancer that activates tyrosine receptor kinases
Papillary and medullary
Hashimotos thyroiditis is a risk factor for which thyroid cancer?
Lymphoma
Cancer arising from the parafollicular C cells
Medullary
Thyroid cancer commonly a/w either a RAS mutation or a PAX8-PPAR gamma 1 rearrangement
Follicular
Thyroid cancer commonly a/w mutation in the BRAF gene (serine/ threonine kinase)
Papillary
What features characterize a deficiency in 3 beta hydroxysteroid dehydrogenase?
Inability to produce glucocorticoids, mineralocorticoids, sex steroids (estrogen or testosterone)
Excessive salt excretion in the urine
Early death
What features characterize a deficiency in 17 alpha hydroxylase?
Inability to produce cortisol or sex hormones-> phenotypically female, unable to mature
Increased production on mineralocorticoids -> sodium and fluid retention -> HTN
What features characterize a deficiency in 21 beta hydroxylase?
Inability to produce cortisol-> incr ACTH
Inability to produce mineralocorticoids -> hypotension
Increased production of sex hormones -> phenotypically male
What features characterize a deficiency in 11 beta hydroxylase?
Inability to produce cortisol or aldosterone
Increased production of deoxycorticosterone (a weak mineralocorticoid) -> HTN
Increased production of sex hormones -> masculinization
An adult male with elevated serum cortisol levels and signs of Cushing’s syndrome undergoes a dexamethasone suppression test. One mg of dexamethasone does not decrease cortisol levels, but 8 mg does. What is the diagnosis?
ACTH producing pituitary adenoma
A very tan child with a pale mother presents to your clinic and is found to be hypotensive. What is the most likely diagnosis?
She likely has Addisons disease = primary adrenal insufficiency. Low cortisol causes increases expression of POMC gene leading to increased ACTH and MSH (which leads to the hyperpigmentation). She also lacks aldosterone with causes the hypotension.
Which oral diabetes drug? Lactic acidosis is a rare but worrisome side effect
Metformin
Which oral diabetes drug? most common side effect is hypogylcemia
Sulfonylurea
Which oral diabetes drug? often used in combination with any of the other oral agents
Metformin
Which oral diabetes drug? Also helps lower Trigs and LDL cholesterol levels
Metformin
Which oral diabetes drug? Not safe in settings of hepatic dysfunction or CHF
Glitazones, metformin
Which oral diabetes drug? Should not be used in patient with elevated serum creatinine
Metformin (d/t lactic acidosis)
Which oral diabetes drug? Should not be used in patient with liver cirrhosis, elevated serum creatinine, or inflammatory bowel disease?
Alpha glucosidase inhibitors
Which oral diabetes drug? hepatic serum transaminase levels should be carefully monitored when using these agents
Glitazones, metformin
Which oral diabetes drug? not associated with weight gain, often used in overweight diabetics
Metformin
Which oral diabetes drug? Metabolized by the liver, excellent choice for diabetics with renal disease
Glitazones
Which oral diabetes drug? Primarily effects prostprandial hyperglycemia
Alpha glucosidase inhibitors
Which oral diabetes drug? MOA: closes K+ channel on beta cells -> depolarization -> Ca++ influx -> insulin release
Sulfonylureas
Which oral diabetes drug? MOA: inhibits alpha glucosidase at intestinal brush border
alpha glucosidase inhibitors
Which oral diabetes drug? MOA: agonist at PPAR gamma receptors -> improved target cell response to insulin
Thiazolidinediones (glitazones)
A 28 year old male with normally well managed IDDM comes in with DKA. He recently has been suffering from a cold and is taking OTC cold medicine. What is the cause of his DKA?
infection can trigger DKA
Which type of diabetes fits the following description? a/w obesity
Type II
Which type of diabetes fits the following description? may cause ketoacidosis
Type I but may be seen in type II if there is insulin dependence
Which type of diabetes fits the following description? Strong genetic predisposition
Type II (even tho type I is HLA-DR3&4)
Which type of diabetes fits the following description? a/e HLA DR3/4
Type I
What are the tumor locations of MEN1?
Pituitary, parathyroid, pancreatic
What are the tumor locations of MEN2a?
Medullary thyroid cancer, parathyroids, pheochromocytoma
What are the tumor locations of MEN2b?
Medullary thyroid cancer, pheochromocytoma, oral/ GI neurofibromas
What are the clinical manifestations of addisons disease?
Increased skin pigmentation, hypotension, weakness, malaise, fatigue, weight loss. (usually caused by autoimmunity -> atrophy leading to decreased aldosterone and cortisol).
What is the mechanism of PTU (propylthiouracil)? What other drug works like PTU? What are their side effects?
Inhibits thyroid peroxidase and 5’ iodinase. Methimazole (thyroid peroxidase only). Agranulocytosis and aplastic crisis (anemia).
What cell type produces PTH? What cell type produces calcitonin?
Chief cells of the parathyroid and parafollicular C cells of the thyroid.
What cancers are associated with RET gene mutation? What else can be associated with RET?
MEN2a and MEN2b -> medullary thyroid cancer. Also papillary thyroid cancer. Familial Hirschprung’s disease is a/w RET mutation.
What are the symptoms of 21 hydroxylase deficiency?
In ability to make cortisol or mineralocorticoids -> hypotension. Excess steroid production -> masculinization.
What are the symptoms of 11 beta hydroxylase deficiency?
Cant make cortisol or aldosterone, but increased production deoxycorticosterone (which is weakly active) -> still causes HTN.
Excess steroid production causes masculinization.
What is the most common chronic arrhythmia?
Afib
What is the most common bacteria in the gut?
Bacteroides fragilis
What is the most common gynecologic malignancy?
Endometrial > uterine cancer
What is the most common primary cardiac tumor in children?
Rhabdomyoma
What is the most common breast cancer?
Invasive ductal carcinoma
