02/17/15 - Endocrine Flashcards
A 40yo female presents with a 3mo history of weight gain, constipation, depressed mood, fatigue and cold intolerance. Thyroid biopsy reveals lymphocytic infiltrate with germinal cell formation. If she has the DR5 subtype, what other disease is she also at risk for?
A. Multiple sclerosis
B. Pernicious anemia
C. Psoriasis
D. Steroid-responsive nephrotic syndrome
B. Pernicious Anemia
DR5 is associated with pernicious anemia and Hashimoto thyroiditis. Multiple sclerosis is seen in the DR2 subtype, Psoriasis with B27.
The liver can convert glucose into G6P and minimize postprandial blood sugar increases. What is the best explanation for this ability?
A. Hepatocyte cell membrane permeability for G6P
B. High maximum reaction rate of glucokinase
C. Inhibition of glucokinase by G6P
D. Lack of glucokinase regulation by insulin
E. Low michaelis-menten constant of glucokinase
B. High maximum reaction rate of glucokinase
The membrane G6P permeability would be bad. Inhibition by G6P would reduce the liver’s capacity to store. Insulin does actually increase glucokinase. Michaelis-menten constant relates to affinity, and is actually high in this reaction.
A genetic mouse knockout’s F2 progeny express low TSH, low FSH, low LH, but normal ACTH and exhibit dwarfism. Female mice have impaired milk secretion. What is the impaired second messenger molecule?
A. cAMP
B. cGMP
C. Inositol triphosphate
D. Steroid nuclear hormone receptor
E. Tyrosine kinase
C. Inositol triphosphate
*Note that Gq is the second messenger for all hypothalamic hormones except CRH. *
A woman has thyroid cancer and is scheduled for a total thyroidectomy. Which complication should she be warned of?
A. Acromegaly
B. Cretinism
C. Hypertension
D. Hypoparathyroidism
E. Renal osteodystrophy
D. Hypoparathyroidism
Due to removal of the parathyroid glands during surgery. Note that renal osteodystrophy results in hypocalcemia resembling hypoparathyroidism, but it is secondary to a renal wasting disorder.
A 5yo patient presents with a painless but growing mass in her neck. It is on the midline, below the hyoid bone. Hormones are normal but surgery is recommended. What is the diagnosis?
A. Branchial cleft cyst
B. Dermoid cyst
C. Ectopic thyroid gland
D. Enlarged pyramidal lobe
E. Thyroglossal duct cyst
E. Thyroglossal duct cyst
Hormone levels are normal, so ectopic gland or enlarged lobe is unlikely. Branchial cleft cysts are generally not midline, and dermoid cysts are more superficial?
Which of the following is standard treatment for thyrotoxicosis?
A. Aspirin
B. Dobutamine
C. Iodine
D. Levothyroxine
E. Propylthiouracil
E. Propylthiouracil
Methimazole would also be an option. Iodine is generally not used alone? Levothyroxine and aspirin would both worsen thyroid hormone levels. Dobutamine will worsen heart failure.
A patient with T1DM develops renal insufficiency. A biopsy shows Kimmelstiel-Wilson nodules. Which medication is effective in delaying this disease’s progression?
A. ACE inhibitors
B. Beta blockers
C. Cyclophosphamide
D. Gold therapy
E. Prednisone
A. ACE Inhibitors
Also works for T2DM, and should be given to all diabetics with microalbuminuria. C/D are completely inappropriate, prednisone will worsen hyperglycemia, and beta-blockers can mask hypoglycemia
A patient presents with a 4mo history of anxiety, palpitations, weight loss, frequent stools, missed menses, and heat intolerance. She has a thyroid bruit and mild exophthalmos. Labs reveal undetectable TSH and elevated T3/T4. What is the etiology of her condition?
A. Autoimmune stimulation of hormone receptors
B. Idiopathic replacement of thyroid tissue with fibrous tissue
C. Thyroid adenoma
D. Thyroid hormone producing ovarian teratoma
E. Viral infection with destruction of thyroid gland
A. Autoimmune stimulation of hormone receptors
IgG receptors stimulate the thyroid (and pretibial tissue, and extraocular muscles). B describes Riedel’s thyroiditis. Adenomas are usually nonfunctional. Ectopic thyroid production does not explain exophthalmos. E is backwards.
A patient presents with HTN, hypokalemia, sodium and water retention and decreased renin activity. Diagnosis?
A. Addison’s disease
B. Hyperthyroidism
C. Pheochromocytoma
D. Primary hyperaldosteronism
E. Secondary hyperaldosteronism
D. Primary hyperaldosteronism
Potassium wasting water & salt retention bespeaks hyperaldosteronism. Low renin activity indicates primary rather than secondary.
A patient presents with hyperglycemia, diarrhea, and weight loss. Metformin hasn’t lowered his blood sugars. Abdominal exam reveals pancreatic mass and a migratory necrolytic erythema. Diagnosis?
A. Prednisone use
B. Glucagonoma
C. Insulinoma
D. T1DM
E. VIPoma
B. Glucagonoma
Glucagonoma is the only cause given which can cause the painful, itchy rash.
A 12yo girl presents with a soft, nontender mass under her tongue. This congenital anomaly does not affect hormone levels, but if it did, the patient might experience which of the following?
A. Amenorrhea
B. Cold intolerance
C. Constipation
D. Hyperlipidemia
E. Weight gain
A. Amenorrhea
The anomaly is a thyroid remnant; amenorrhea can be seen in thyrotoxicosis due to the increase in metabolic rate. All other answers given are symptoms of hypothyroidism.
A patient with ulcerative colitis has been treated for 6mo with prednisone. The treatment has caused him to develop another condition. Which is the most likely adverse effect of the drug?
A. Diabetes insipidus
B. Diabetes mellitus
C. Hyperpigmented skin
D. Hypotension
E. Muscle hypertropy
B. Diabetes mellitus
Steroids elevated blood glucose levels. Hyperpigmented skin is seen in primary Addison’s disease. Steroids promote hypertension and muscle atrophy.
The physical exam of a diabetic patient yields a loss of vibrational sense on the great toe. Which receptor is most likely affected?
A. Krause end bulb
B. Meissner’s corpuscle
C. Merkel disc
D. Pacinian corpuscle
E. Ruffini corpuscle
D. Pacinian corpuscle
Pacinian corpuscles are deep and detect vibration. Merkel discs are superficial for fine touch. Ruffini corpuscles transduce pressure, and Meissner’s corpuscles convey light touch & discrimination.
A patient presents with symptoms of hypoglycemia and is found to have a blood glucose of 50. Abdominal CT yields an insulinoma in the head of the pancreas. Which vascular structures must be ligated during the resection?
A. Gastroduodenal + IMA
B. Gastroduodenal + SMA
C. L-Gastric + IMA
D. L-Gastric + SMA
E. Proper Hepatic + IMA
F. Proper Hepatic + SMA
B. Gastroduodenal + SMA
The pancreas is supplied dually by the celiac and SMA. Of the celiac, L-Gastric supplies the lesser curvature of the stomach, the hepatics supply the liver & biliary tree, and the gastroduodenal gives rise to the pancreaticoduodenal arteries.
A 35yo woman presents with amenorrhea and enlargement of the hands and feet. She has hypertension, coarse facial features, and mild macroglossia. What treatment is appropriate?
A. Finasteride
B. Leuprolide
C. Octreotide
D. Recombinant growth hormone
C. Octreotide
This is acromegaly; finasteride blocks 5a-reductase, leuprolide is a GnRH analog, and rGH is for deficiency, not excess.
A 25yo man has intermittent headaches, anxiety and palpitations. His uncle had similar complaints, and his mother & two cousins have all had thyroidectomies. What condition does your patient most likely have?
A. Acromegaly
B. ACTH-secreting pituitary adenoma
C. Hyperparathyroidism
D. A nonfunctioning pituitary adenoma
E. Pheochromocytoma
E. Pheochromocytoma
This is MEN2, of which the triad includes pheochromocytoma, medullary thyroid carcinoma, and parathyroid adenoma. The symptoms of headache and SNS dysregulation further support the presence of a pheochromocytoma.
