ENDOCRINE

Question 1

most common type of thyroid cancer radiation-induced

Answer 1

papillary.

Subsequent development of thyroid neoplasia is associated with a dose of 5 to 20 cGy.

The risk is lower with higher levels of radiation!
[ probably because of the cytotoxic effect of higher doses ]

The latency period has been reported to be as long as 40 years.

Question 2

gold standard in initial evaluation and diagnostic tool for thyroid masses

Answer 2

Fine-needle aspiration biopsy (FNAB)

However, tissue diagnosis remains as the best predictor for surgical intervention. Majority of nodules sampled by

FNAD can be categorized as benign (65%), suspicious (20%), and malignant (5%).

Question 3

management of thyroid Nodules in the suspicious category

Answer 3

SESAP is surgery siting 20-30% malignancy rate

SCORE says
a repeat biopsy or be subjected to other modes of characterization.

Question 4

associated with production of calcitonin

Answer 4

Medullary thyroid carcinoma

parafollicular or C cells

Question 5

The superior parathyroids are usually where give landmarks of nerve and thyroid gland where are ectopic sites

Answer 5

POSTERIOR and LATERAL to recurrent laryngeal nerve

1 cm above the junction of the nerve and the inferior thyroid artery

Embedded in fat along the posterior surface of the middle or upper portions of the thyroid lobes

Occasionally, a superior parathyroid may be found within the substance of the thyroid gland.

Other aberrant sites for the superior parathyroids include:
tracheoesophageal groove
retroesophageal space
posterior mediastinum

Question 6

The inferior parathyroids are located

Answer 6

ANTERIOR and MEDIAL
to the recurrent laryngeal nerve

near the lower pole of the thyroid

or in the thyrothymic ligament

Question 7

the most bioactive form of thyroid hormone.

Answer 7

T3

20% of T3 is secreted directly from the thyroid and

80% is derived by peripheral conversion from T4.

Question 8

Renin is an enzyme secreted by

Answer 8

the juxtaglomerular cells of the kidney in response to decreased pressure in the renal afferent arterioles.

Question 9

stimulation of Renin

Answer 9

Decreases in plasma sodium concentration sensed by osmoreceptors in the cells of the macula densa promote renin release as well.

Renin secretion is also stimulated by
hyperkalemia
HYPOnatriemia - which ultimately leads to release of angiotensin II that directly stimulates secretion of aldosterone.

inhibited by potassium depletion.

Question 10

The major physiologic regulator of aldosterone secretion is

Answer 10

the renin–angiotensin system and angiotensin II directly stimulates secretion of aldosterone.

Question 11

Somatostatin primary functions

Answer 11

Prolongs gastric emptying time.

decrease production of gastric acid

inhibit secretion of other peptide hormones including gastrin

Inhibits insulin secretion

Question 12

most sensitive means to identify tumor recurrence in the thyroid bed or involvement of lymph nodes by metastatic disease during postoperative surveillance of patients with thyroid cancer.

Answer 12

Ultrasound!

Question 13

roles of ultrasound for assessing thyroid mass

Answer 13

To preoperatively assess for evidence of tumor invasion into surrounding structures or for evidence of lymphadenopathy or abnormal-appearing lymph nodes!

To assess the thyroid gland and any nodules within it

As an adjunct to confirm needle placement during fine-needle aspiration of a thyroid nodule

Question 14

Thyrotropin-releasing hormone is synthesized in the

Answer 14

hypothalamus

paraventricular nucleus of the hypothalamus.

It is a tropic hormone that stimulates the release of thyroid-stimulating hormone (TSH) and prolactin from the anterior pituitary gland.

Question 15

management of indeterminate cytology on FNA of the thyroid nodule

Answer 15

“There is a 20% chance that an indeterminant specimen is actually a thyroid malignancy. “

Since there is no other test that would accurately determine the malignancy of the lesion, a thyroid lobectomy for diagnosis is the next most appropriate step in management.

If the lesion turned out to be a malignant thyroid neoplasm on final pathology, a reoperation for a completion thyroidectomy would be performed.

An alternative approach would be to offer a total thyroidectomy up front, which would eliminate the risk of reoperation but would require lifelong thyroid replacement therapy.

A thyroid lobectomy for diagnosis is considered the most appropriate management in this question scenario.

Question 16

management of benign category FNA findings on thyroid nodule workup

Answer 16

Patients with a benign FNAB are recommended to undergo a repeat FNAB in 6 months.

If they continue to be asymptomatic, the nodule is unchanged, and the FNAB continues to be benign, they are recommended to continue with observation and yearly follow up.

Question 17

external branch of the superior laryngeal nerve innervated

Answer 17

The cricothyroid muscle is innervated (CAREFUL-this is not cricopharyngeus)

functions to help maintain tension on the vocal cords.

Question 18

arytenoids innervation and function

Answer 18

help form the intrinsic musculature of the larynx

innervated by the inferior laryngeal nerve,

which is the terminal branch of the recurrent laryngeal nerve.

Question 19

intrinsic muscles of the larynx innervation

Answer 19

The are innervated by the recurrent laryngeal nerve.

Question 20

Cricopharyngeus innervation and function

Answer 20

The cricopharyngeus is part of the inferior constrictor of the pharynx and is innervated by branches of the glossopharyngeal and vagus nerves

CAREFUL-this is not cricothyroid muscle innervated by the external branch the superior laryngeal nerve

Question 21

Sternothyroid muscle location and innervation

Answer 21

one of the infrahyoid muscles of the neck,

all of which are innervated by upper cervical nerve fibers through the ansa cervicalis.

Question 22

necessary for the induction of phenylethanolamine-N-methyltransferase activity, which catalyzes the conversion of norepinephrine to epinephrine.

Answer 22

Cortisol.

Question 23

Catechol-o-methyl transferase (COMT)

Answer 23

the enzyme principally responsible for metabolism of the circulating catecholamines.

Question 24

Catecholamine synthesis begins with

Answer 24

hepatic synthesis of tyrosine from phenylalanine and dietary sources.

Question 25

most common cause of hypocalcemia after total thyroidectomy

Answer 25

Operative injury or excision of the parathyroid glands!! The cause of the hypocalcemia is usually temporary, reversible ischemia of the parathyroid tissue, and hypocalcemia provides the maximum stimulus for the secretion of parathyroid hormone.

Question 26

decision algorithm of treating a low serum calcium after total thyroidectomy

Answer 26

whether the patient has signs and symptoms of hypocalcemia, such as paresthesias in the fingers, toes, or circumoral region; carpopedal spasm; agitation; laryngeal stridor; or a positive Chvostek's sign. If the patient is asymptomatic and calcium is >= 7.5 mg/dL, simple monitoring of symptoms and calcium levels is the preferred method of management.

Question 27

effective treatment for a symptomatic patient whose serum calcium is less than 7.5 mg/dL.

Answer 27

Intravenous or oral calcium or vitamin D Oral calcium may be adequate for mild symptoms, but patients with severe symptoms such as carpal pedal spasm or laryngeal stridor 253should receive intravenous calcium, either as 10% calcium gluconate, which has a calcium content of 90 mg or 4.5 mEq, or 10% calcium chloride, which has a calcium content of 270 mg or 13.5 mEq.

Question 28

VIP-secreting tumors are associated with

Answer 28

secretory diarrhea and profound hypokalemia

Question 29

Somatostatinoma are associated with

Answer 29

These include dyspepsia, mild diabetes mellitus, gallbladder disease, steatorrhea, and hypochlorhydria

Question 30

Glucagonoma are associated with

Answer 30

frequently malignant pancreatic endocrine neoplasms characterized by elevated plasma glucagon levels that result in glucose intolerance and diabetes mellitus. These patients also have a characteristic necrolytic migratory erythematous skin rash as well as weight loss and anemia.

Question 31

Gastrinoma are associated with

Answer 31

Gastrinomas are associated with the development of virulent peptic ulcer disease and diarrhea (Zollinger-Ellison syndrome). Diabetes mellitus and skin rashes are not a part of this syndrome.

Question 32

Pancreatic polypeptidoma are associated with

Answer 32

Pancreatic polypeptide secreting tumors of the pancreas are not associated with any identifiable clinical syndrome.

Question 33

Excess iodide suppresses

Answer 33

both iodide transport and hormone synthesis but does not affect peripheral conversion of T4 to T3.

Question 34

Methimazole

Answer 34

Methimazole member of the thionamide class of antithyroid drugs and inhibits thyroid hormone synthesis.

Question 35

Dopamine effects on thyroid

Answer 35

inhibits pituitary secretion of TSH

Question 36

Propranolol effects on thyroid

Answer 36

β-adrenergic receptor blocker, controlling the peripheral manifestations of increased catecholamines sensitivity in patients with thyrotoxicosis. It also has the effect of blocking peripheral conversion of T4 to T3, thereby slowing the metabolism rate of thyroid hormone.

Question 37

Lithium effects on thyroid

Answer 37

Lithium inhibits the release of thyroid hormone

Question 38

Verner-Morrison syndrome

Answer 38

is a secretory diarrhea, high levels of circulating VIP, and a pancreatic tumor.

Question 39

99m technetium sestamibi, scanning

Answer 39

Preoperative imaging can help to localize a parathyroid adenoma and thereby guide a surgeon’s exploration. preferential uptake in abnormally enlarged parathyroid glands. It has a sensitivity of up to 80% but does not have good success in identifying small adenomas.

Question 40

New thyroid nodules more likely to be malignant

Answer 40

New thyroid nodules at the extremes of age are more likely to be malignant than one that occurs in the third through seventh decade.

Question 41

The risk of a solitary thyroid nodule in a child less than 14 years old being malignant

Answer 41

The risk of a solitary thyroid nodule in a child less than 14 years old being malignant may be as high as 50%.!

Question 42

A new thyroid nodule after the age of 60 is more likely to be malignant in a man or a woman

Answer 42

MAN

Question 43

Excess aldosterone leads to

Answer 43

sodium retention and expansion of the extracellular fluid volume, which feeds back on the renal juxtaglomerular cells and macula densa to shut off renin production. Both potassium and hydrogen ions are excreted in the urine in exchange for sodium, which results in potassium depletion and alkalosis. Movement of hydrogen ion into the cells to replace intracellular potassium also contributes to the alkalosis. Mild glucose intolerance may accompany significant potassium depletion.

Question 44

Renin secretion is stimulated and inhibited by what lytes

Answer 44

hyperkalemia stimulated hypokalemia inhibited

Question 45

Patients with primary aldosteronism will have what K finding

Answer 45

hypokalemic

Question 46

where are cells that down regulate renin

Answer 46

renal juxtaglomerular cells and macula densa to shut off renin production (in response to increase extracellular VOLUME expansion)

Question 47

Aldosterone stimulates

Answer 47

renal tubular reabsorption of sodium in exchange for potassium and hydrogen ion with the net effect of fluid reabsorption and expansion of the intravascular volume.

Question 48

where are cells that regulate renin and what effects them

Answer 48

Renin is secreted by the juxtaglomerular cells of the kidney primarily in response to decreased pressure in the renal afferent arteroles.

Question 49

Calcitonin is a polypeptide hormone secreted by

Answer 49

parafollicular, or C- cells, of the thyroid gland.

Question 50

Calcitonin acts to

Answer 50

reduce serum calcium levels opposes the actions of parathyroid hormone. Its mechanism of action is through the inhibition of 1) osteoclast-mediated bone resorption, 2) absorption by the intestine, 3) resorption of calcium by the renal tubular cells.

Question 51

Secretion of calcitonin is stimulated by

Answer 51

an increase in serum calcium, gastrin, or pentagastrin.

Question 52

Calcitonin is often used as a post-operative marker to monitor for recurrence of

Answer 52

Medullary thyroid cancer arise from C-cells of the thyroid.

Question 53

the most reliable test for distinguishing primary hyperparathyroidism from hypercalcemia of malignancy.

Answer 53

Measurement of intact PTH levels is Patients with hypercalcemia of malignancy should have low levels of intact parathyroid hormone.

Question 54

Nelson syndrome includes

Answer 54

INCR ACTH (rather than just incr cortisol in cushings) progressive hyperpigmentation, visual field loss, amenorrhea associated with elevated adrenocorticotropic hormone levels. It was originally described in a patient who had a functional pituitary adenoma and who had undergone bilateral adrenalectomy for hypercortisolism. This syndrome today generally represents a missed diagnosis of Cushing disease that has been treated with adrenalectomy. Often these tumors are aggressive or occasionally malignant. Multiple endocrine neoplasia type 1 (Wermer syndrome) includes pituitary adenoma, hyperparathyroidism, and multiple pancreatic endocrine tumors.

Question 55

Arteriography, venography, and selective venous sampling to work up adrenal

Answer 55

have become less popular as experience with other imaging techniques has become greater. Invasive procedures with intravascular contrast agents have clear disadvantages. Arteriography is especially dangerous in examinations of patients with pheochromocytoma.

Question 56

Appropriate tests include screening for primary hyperparathyroidism

Answer 56

``` serum levels of calcium parathyroid hormone (PTH), ``` screening for pituitary adenoma with prolactin level, as this tumor is the most frequent functional pituitary tumor in the syndrome. (if suspect MEN)

Question 57

differential diagnosis of hypocalcemia includes

Answer 57

DiGeorge syndrome causes hypocalcemia due to congenital absence of the parathyroids and the thymus. DCR magnesium affects PTH secretion in a less potent, but qualitatively similar manner to calcium, severe hypomagnesemia paradoxically inhibits PTH secretion. This occurs probably as a result of interference with intracellular secretory mechanisms. Hypocalcemia in patients with profound hypomagnesemia will not respond to calcium administration until the hypomagnesemia has been corrected. Pseudohypoparathyroidism is a rare disorder characterized by target tissue resistance to PTH, hypocalcemia, and congenital defects in growth and skeletal development.

Question 58

most common cause of hypocalcemia.

Answer 58

surgical removal or injury of the parathyroid glands

Question 59

The best initial test to evaluate a patient with suspected Cushing syndrome is:

Answer 59

cortisol excretion in the urine over a 24-hour time period. Elevated levels are present in more than 90% of patients with Cushing syndrome.

Question 60

The high-dose dexamethasone test has been used primarily to differentiate

Answer 60

pituitary from nonpituitary causes of ACTH-dependent Cushing syndrome. It is generally not used as an initial screening test for persons with suspected hypercortisolism.

Question 61

Glasgow coma scale, pupillary function, and lateralized extremity weakness if present together is most often associated with what head trauma situation

Answer 61

a focal mass lesion, such as subdural, epidural intracerebral hematoma.

Question 62

Subdural hematoma

Answer 62

most common, occurring in 20% to 40% of severely head-injured patients. The combination of progressive hypertension associated with bradycardia and a diminished respiratory rate (the Cushing response) strongly suggests a rise in intracranial pressure due to a mass lesion.

Question 63

Glasgow coma scale abnormalities without pupillary change or lateralized extremity weakness may signify

Answer 63

diffuse brain injury, in particular, diffuse axonal injury, concussion, or hypoxemia.

Question 64

subarachnoid characterized by

Answer 64

depressed level of consciousness, severe headache, photophobia.

Question 65

Nasopharyngeal carcinoma

Answer 65

higher in Asians for reasons that are not fully understood. adults, a neck mass that represents lymphatic spread of the tumor is the most frequent presenting sign. The tumor has a variety of histologic patterns, including keratinizing squamous cell carcinoma, spindle cell carcinoma, round cell carcinoma, and mixed nonkeratinizing carcinoma. Although epistaxis, hearing loss, nasal stuffiness, and cranial nerve palsy may all be part of the initial presentation, a painless neck mass is the most common. Epistaxis is usually the result of erosion by the tumor of superficial mucosal blood vessels in the anterior nares. Hearing loss and nasal stuffiness occur secondary to obstruction of the choanae or the eustachian tubes by the tumor mass. Cranial nerve paralyses occur after bony erosion of the base of the skull. The trigeminal, oculomotor, and abducens are the most frequent cranial nerves involved.

Question 66

The standard compliance or volume-pressure curve is drawn by means of measuring

Answer 66

volume and pressure at stages of lung deflation after total inflation.

Question 67

The decreased compliance in acute respiratory distress syndrome occurs because

Answer 67

the lung is smaller (from colapsed alveoli) In acute respiratory failure, the cause of decreased compliance is almost always associated with a decrease in functional residual capacity. The decreased functional residual capacity represents lost alveoli, which are either collapsed or filled with fluid but still perfused with blood.

Question 68

All of the following serum tumor markers can be seen in seminoma except:

Answer 68

AFP! NOT in seminoma BHCG rare in seminoma approximately 10–15% of classical seminomas. Elevated alkaline phosphatase can be seen in the presence of seminoma. Elevated lactate dehydrogenase can be elevated in the presence of seminoma.

Question 69

Some cell surface markers are unique to a species

Answer 69

(xenospecific).

Question 70

Some markers are unique to a group of individuals within a species

Answer 70

(allospecific).

Question 71

Some markers are completely unique to the individual itself

Answer 71

(autospecific).

Question 72

associated with the development of Kaposi sarcoma.

Answer 72

Herpesvirus type-8

Question 73

associated with Burkitt lymphoma,

Answer 73

Epstein-Barr virus.

Question 74

pseudohypoparathyroidism, associated findings include

Answer 74

target tissue resistance to parathyroid hormone (PTH), low serum calcium, elevated serum phosphate, defect in skeletal growth and development. rare familial disorder parathyroid hormone function itself is normal, but the kidney cannot respond to PTH stimulation. This results in hypocalcemia and hyperphosphatemia.

Question 75

he essential steps in the laboratory evaluation of patients with Cushing syndrome overview broad

Answer 75

documentation of excess adrenal cortisol production, differentiation of ACTH-dependent from independent causes, localization of the source.

Question 76

used to differentiate adrenal causes from nonadrenal causes of Cushing syndrome.

Answer 76

Plasma ACTH levels are Patients with cortisol-secreting adrenal tumors should have suppressed ACTH levels to less than 20 pg/mL.

Question 77

differentiating pituitary from nonpituitary causes of ACTH-dependent Cushing syndrome.

Answer 77

Inferior petrosal sinus sampling for ACTH test

Question 78

The metabolic actions of insulin include

Answer 78

Inhibition of lipolysis in adipocytes. to promote the storage of triglycerides, increase glucose transport into adipocytes, and inhibit lipolysis. stimulates synthesis of proteins in liver and muscle and stimulates the formation of very low-density lipoproteins. Stimulates glycogen synthesis and storage and inhibits its breakdown. Inhibition of gluconeogenesis with reduction in cellular catabolism in part by inhibiting hepatic gluconeogenesis and glycogenolysis.

Question 79

the most common causes of Cushing syndrome

Answer 79

ACTH-secreting tumors of the pituitary also termed Cushing disease, account for approximately 70% of all cases. Primary adrenal tumors account for only 15% to 20% of cases of Cushing syndrome. Ectopic ACTH-secreting tumors comprise approximately 15% of cases of Cushing syndrome. The most common ectopic ACTH-secreting tumors are small cell lung carcinomas.

Question 80

The percentage of total plasma calcium that is protein bound is, however, affected by changes in

Answer 80

plasma pH, as hydrogen ion competes with calcium for the same binding site on plasma proteins. This results in an increase in the percentage of ionized calcium in acidosis, whereas in alkalosis the proportion of ionized calcium ion is decreased.

Question 81

Biochemical abnormalities that may accompany hypercalcemia in patients with primary hyperparathyroidism include

Answer 81

Elevation of the chloride: phosphate ratio to greater than 33 is seen in many patients with HPT. Metabolic acidosis (not alkalosis) is more commonly associated with primary hyperparathyroidism because of increased urinary excretion of bicarbonate. Elevated alkaline phosphatase elevated in patients with bone disease from hyperparathyroidism due to an increase in osteoclastic bone resorption. Hypophosphatemia due to the phosphaturic actions of PTH on the kidney. Hyperchloremia - hyperchloremic metabolic acidosis from increased urinary excretion of bicarbonate. Hypomagnesemia seen in approximately 5% to 10% of patients with primary hyperparathyroidism.

Question 82

The organ of Zuckerkandl, located and function

Answer 82

adjacent to the origin of the inferior mesenteric artery, is a common site for extra-adrenal chromaffin tissue. It is the only chromaffin tissue outside the adrenal gland that contains the enzyme phenylethanolamine N-methyl transferase necessary for conversion of norepinephrine to epinephrine.

Question 83

increase lower esophageal sphincter pressure

Answer 83

α-adrenergic neurotransmitters or beta-blockers The hormones gastrin motilin antacids, cholinergic agonists, metoclopramide,

Question 84

decrease lower esophageal pressure

Answer 84

alpha-blockers and β stimulants ``` cholecystokinin, estrogen, glucagon, progesterone, somatostatin, secretin ``` ``` Anticholinergics, barbiturates, calcium channel blockers, caffeine, diazepam, theophylline ``` ``` Peppermint, chocolate, coffee, ethanol, fat ```

Question 85

the most common neoplasm of the endocrine pancreas

Answer 85

Insulinoma

Question 86

Insulinoma location

Answer 86

distributed equally in the head, body, and tail of the pancreas.

Question 87

Insulinoma Preoperative localize success rate and first choice

Answer 87

Preoperative selective visceral angiography will localize more than 90% of solitary adenomas. The diagnosis is most reliably established with a monitored fast. Insulin and glucose levels are then obtained every four to six hours. Normal persons have insulin/glucose ratios less than 0.3, whereas patients with insulinoma demonstrate insulin/glucose ratios greater than 0.4 following a prolonged fast. Elevated levels of proinsulin and C peptide are also found in patients with insulinoma. Intraoperative ultrasonography may eliminate the need for preoperative localization studies. This imaging technique can identify insulinomas with a sensitivity of 90% to 95%, and also characterizes the relationship of the tumor to the pancreatic duct and the vascular structures. (1995 SCORE refs)

Question 88

PTH effect on Ca, phos, D, and bicarb at the kidney

Answer 88

increase reabsorption of calcium PTH stimulates the hydroxylation of 25-hydroxy vitamin D and inhibits the reabsorption of phosphate. bicarbonate

Question 89

test is used to distinguish pituitary from nonpituitary causes of ACTH-dependent Cushing syndrome

Answer 89

high-dose dexamethasone next test performed when 24 urine cortisol up and ACTH is up supraphysiologic doses of glucocorticoids will SUPPRESS the hypothalamic-PITuitary axis in patients with a pituitary tumor NO affect on cortisol production in patients with ECTOPIC ACTH-secreting tumors.

Question 90

diagnostic categories for reporting thyroid cytopathology

Answer 90

Benign Consistent with a benign follicular nodule (includes adenomatoid nodule, colloid nodule, etc.) Consistent with lymphocytic (Hashimoto’s) thyroiditis in the proper clinical context Consistent with granulomatous (subacute) thyroiditis

Question 91

management of thyroid FNA when finding is: Nondiagnostic or unsatisfactory

Answer 91

Repeat FNA with ultrasound scan guidance

Question 92

management of thyroid FNA when finding is: Benign

Answer 92

Clinical follow-up only

Question 93

management of thyroid FNA when finding is: Atypia of undetermined significance or follicular lesion of undetermined significance

Answer 93

REPEAT! FNA (CAREFUL, Atypia of undetermined significance or follicular only gets repeat FNA while, suspicious for a follicular neoplasm gets LOBECTOMY!!)

Question 94

management of thyroid FNA when finding is: Follicular neoplasm or suspicious for a follicular neoplasm

Answer 94

Surgical lobectomy

Question 95

management of thyroid FNA when finding is: Suspicious for malignancy

Answer 95

Near-total thyroidectomy or surgical lobectomy‡

Question 96

management of thyroid FNA when finding is: Malignant

Answer 96

Near-total thyroidectomy

Question 97

Thyroid storm

Answer 97

clinical manifestations are fever, sweating, and tachycardia and occasionally nausea, vomiting, and abdominal pain. Congestive heart failure, pulmonary edema, restlessness, delirium, and psychoses may also develop. coma occurs and death Either PTU or methimazole should be administered to slow the release of thyroid hormone, unless the thyroid storm has occurred after thyroidectomy. PTU inhibits peripheral conversion of T4 to T3, whereas methimazole does not and therefore is the preferred thionamide. BETA-blockers such as propranolol are given to block the adrenergic effects continue until the morning of surgery and should not be stopped abruptly postoperatively. Steroids such as dexamethasone may aid in inhibiting peripheral conversion of T4 to T3 Lugol's solution can be administered as 5 to 10 drops three times daily for 2 weeks preoperatively to decrease vascularity