ENDOCRINE

Question 1

The most common neoplasms causing ectopic ACTH-secretion are

Answer 1

small cell lung cancer (50%);

malignant thymic tumors (20%);

less commonly,

neuroendocrine tumors of the pancreas or gut (carcinoid),

medullary thyroid cancer,

pheochromocytoma.

Question 2

the most common cause of ectopic ACTH secretion.

Answer 2

small cell lung cancer

Question 3

ACTH-independent causes of Cushing syndrome are what is workup

Answer 3

a unilateral adrenal adenoma (10%)

adrenocortical carcinoma (10%).

Abdominal CT can localize most ACTH-independent lesions.

Question 4

FOR bilateral adrenal lesions what is work up of choice

Answer 4

iodocholesterol scanning is helpful to determine which adrenal gland contains the hyperfunctioning adenoma.

Question 5

The biochemical diagnosis of Cushing syndrome

Answer 5

A low-dose dexamethasone suppression test consists of administering 1–2 mg of dexamethasone at 11:00 PM with plasma cortisol levels measured at 8:00 AM the following day.

Normally there is a suppression of plasma cortisol with dexamethasone treatment, which does not occur in patients with Cushing syndrome.

24-hour urine levels of free cortisol

midnight salivary cortisol levels.

Question 6

Diagnosis of pheochromocytoma

Answer 6

Either CT or MRI is recommended for initial tumor localization, with MRI preferred in children and pregnant or lactating women because of concerns regarding ionizing radiation exposure.

Imaging using 123I-labeled metaiodobenzylguanidine (MIBG) scan is often used in patients with pheochromocytomas.
but not required before initial operative intervention.

Question 7

The benefit of routine postoperative radioactive iodine (RAI) ablation in the management of patients undergoing total thyroidectomy

Answer 7

IF low-risk patients undergoing total thyroidectomy for differentiated thyroid cancer is benefit unclear.

RAI is used is to eradicate persistent neoplastic foci in the thyroid bed and lymph node basins, as well as remnants of nonneoplastic thyroid tissue capable of producing thyroglobulin.

In doing so, RAI facilitates surveillance and may decrease disease recurrence.

Routine postoperative RAI is currently not recommended for stage I, low-risk patients.

However, postoperative RAI is indicated, even in the absence of nodal disease, if thyroglobulin antibodies are present.

Thyroglobulin antibodies are present in up to 25% of patients with thyroid cancer. The goal of RAI in the presence of thyroglobulin antibodies is suppression of the source of antigen, which facilitates the disappearance of antibodies and improves future thyroglobulin detection.

Question 8

wrist criteria both low risk thyroid cancer.

mortality risks in patients with thyroid cancer.

Answer 8

Young patients (<45 years)

well-differentiated papillary or follicular tumors

less than 4 cm in diameter,

no
direct extrathyroidal extension beyond the thyroid capsule

no evidence of nodes

no distant metastases

Question 9

Role of thyroglobulin and thyroid cancer

Answer 9

sensitive marker of tumor recurrence after total thyroidectomy and RAI detection after ablation is a

Thyroglobulin antibodies are present in up to 25% of patients with thyroid cancer. The goal of RAI in the presence of thyroglobulin antibodies is suppression of the source of antigen, which facilitates the disappearance of antibodies and improves future thyroglobulin detection.

Question 10

biochemical workup for patient who does not have a clear diagnosis of primary hyperparathyroidism (PHPT)

Answer 10

ionized calcium,
creatinine,
albumin,
25-OH Vitamin D levels

A chloride:phosphate (Cl:PO4) ratio greater than 33 lends further support to the diagnosis.

Vitamin D deficiency is common in the setting of PHPT and warrants replacement, because increased parathyroid hormone (PTH) results in increased clearance and degradation of Vitamin D.

A 24-hour urine collection for calcium and creatinine may also be indicated to exclude a renal calcium leak causing a secondary rise in PTH.

Question 11

primary hyperparathyroidism relationship of calcium to parathyroid hormone level

Answer 11

hypercalcemia in the face of a nonsuppressed PTH level.

Question 12

in primary hyperparathyroidism general guidelines for surgery in an otherwise asymptomatic patient require

Answer 12

a total corrected serum calcium greater than 1.0 mg/dL above the upper limit of normal for the local laboratory (upper normal usually about 10.5)

creatinine clearance less than 60 mL/min ( decreased renal function causes calcium leak from the kidneys)

abnormal bone density T-score –2.5 or less.

A 24-hour urine fractional excretion of calcium

Question 13

rule out familial hypocalciuric hypercalcemia with what test

Answer 13

24-hour urine fractional excretion of calcium

Question 14

possibly effective medical management of hyperparathyroidism

Answer 14

if mild primary hyperparathyroidism

bisphosphonates and estrogen may be as effective as surgery in increasing bone density in patients with mild PHPT.

Cinacalcet for mild chronic renal failure cause

Question 15

Cinacalcet

Answer 15

binds to calcium-sensing receptors on parathyroid cells and causes these receptors to become more sensitive to serum calcium, suppressing PTH release through negative feedback.

The drug is approved by the US Food and Drug Administration only for use in treating secondary hyperparathyroidism associated with chronic renal disease or parathyroid cancer, as well as in complicated nonoperative candidates.

Question 16

The approach to evaluating an adrenal “incidentaloma”

Answer 16

2 issues: whether the lesion is malignant and whether it is hormonally active.

All primary adrenal tumors with suspicious radiological findings, and most functional tumors, should be resected.

Question 17

benign appearing adrenal tumor of what size is resected anyway

Answer 17

Tumors at least 4 cm that lack characteristic benign features on imaging should be resected.

Question 18

CT findings of adrenal incidentalomas with benign versus malignant characteristics

Answer 18

Hounsfield units (HU) is a sensitive tool for differentiating benign from malignant adrenal masses.

A lesion with fewer than 20 HU on noncontrast CT has a 100% specificity for being benign.

Characteristics of malignancy suggested on CT:
large (>6 cm) lesion,
irregular borders,
inhomogeneity,
calcifications,
contrast “washout” of less than 40% after 15 minutes.

Question 19

management of adrenal incidentaloma without malignant features

Answer 19

asymptomatic patients with an incidentally identified adrenal mass should be screened for hormonal activity. to rule out pheochromocytoma

fractionated plasma-free metanephrines most sensitive

although plasma levels alone are not specific for the diagnosis.

Measurement of urine fractionated metanephrine and catecholamine levels is less sensitive

helpful in detecting hormonally active adrenal masses:
Free urine cortisol levels
plasma adrenocorticotropic hormone
aldosterone-to-renin

Question 20

total R. for papillary thyroid cancer is recommended when

Answer 20

recommended for tumors greater than 1.0 cm.

Question 21

the advantages of total thyroidectomy for papillary thyroid cancer

Answer 21

facilitates postoperative radioactive iodine ablation and surveillance with thyroglobulin measurement

decreases the risk of local recurrence

improves survival compared with lobectomy ( for tumors 1 cm or greater?)

Question 22

Most common site of nodal metastases of thyroid papillary cancer

Answer 22

The central neck (level 6) is the most common site of nodal metastases.

Question 23

Central neck dissection boundaries

Answer 23

(bordered by the hyoid bone, innominate vein, and carotid sheath bilaterally)

Question 24

when is a central neck dissection recommended for thyroid papillary cancer

Answer 24

with preoperatively or intraoperatively identified involved central (?or lateral neck nodes?)

consideration for prophylactic central neck dissection, particularly in patients older than 45 years who may be upstaged by the presence of lymph node metastases.

Question 25

treatment of lateral nodal disease and papillary thyroid cancer

Answer 25

Lymph nodes in the lateral neck (levels 2–5) may be involved with PTC.

Modified radical neck dissection is recommended for preoperatively or intraoperatively identified involved lateral neck nodes. Prophylactic modified radical neck dissection is not recommended for PTC.

Question 26

inferior parathyroid glands arise from to descend where

Answer 26

the third pharyngeal pouch and migrate with the thymus

ANTERIOR to the recurrent laryngeal nerve (RLN).

Question 27

where our inferior parathyroid glands typically found

Answer 27

Inferior glands are typically within 1 cm of the inferior pole of the thyroid.

Question 28

list the 2 most common ectopic location of inferior parathyroid

Answer 28

for inferior glands include the 
cervical thymus (22%) 
intimate with the thyroid capsule (17%).

Question 29

superior glands arise from the fourth pharyngeal pouch are typically found where

Answer 29

remain close to the posterior mid thyroid

POSTERIOR to the RLN.

Question 30

which has more commonly an ectopic position inferior or superior parathyroids

Answer 30

inferior parathyroids most commonly ectopic because of increased distance of travel

Question 31

the majority of the superior parathyroid glands are found where

Answer 31

within a 2-cm diameter area centered 1 cm above the intersection of the inferior thyroid artery and RLN (85%)

Question 32

most common ectopic locations for superior parathyroid glands

Answer 32

Superior glands may extend posterior and caudal to the inferior thyroid artery deep in the tracheoesophageal groove.

It is important to carry the surgical dissection back to the prevertebral fascia to identify superior glands that can be posteriorly situated in the paraesophageal and retroesophageal position.

Approximately 3% of ectopic superior parathyroid glands are at or above the superior pole of the thyroid.

Question 33

The incidence of supernumerary parathyroid glands is

Answer 33

10–15%.

Question 34

The most common location for a supernumerary gland is

Answer 34

the thymus.

more rare sites of ectopic parathyroid glands include

carotid sheath

inside the thyroid gland

Question 35

Potential cytologic results obtained by FNA include

Answer 35

benign,

malignant,

nondiagnostic (inadequate cellularity for evaluation),

indeterminate (meets cytologic criteria for specimen adequacy, but lesion is incompletely characterized by cytology alone).

Atypia of undetermined significance (AUS) is reserved for cases in which the cytologic findings are not definitively benign, but the degree of cellular or architectural atypia is insufficient for an interpretation of follicular neoplasm or suspicious for malignancy.

Question 36

The benign cytologic category includes for thyroid

Answer 36

nodular goiter,
chronic lymphocytic thyroiditis,
hyperplastic nodule,
colloid nodule.

Question 37

For asymptomatic nodules with benign cytology, what is recommended management

Answer 37

follow-up is recommended at 6–18 month intervals

for 3–5 years.

Question 38

Atypia of undetermined significance (AUS) is defined as what and what his management

Answer 38

cytologic findings are not definitively benign,

but the degree of cellular or architectural atypia is insufficient for an interpretation of follicular neoplasm or suspicious for malignancy.

Repeat FNA, which may include application of molecular markers, is suggested for asymptomatic nodules with AUS cytology.

Question 39

management of indeterminate cytology for thyroid nodule

Answer 39

Because of the intermediate risk of malignancy (20–30%), surgery is typically recommended for definitive diagnosis of nodules characterized as suspicious for follicular neoplasm by cytology.

Question 40

The differential diagnosis of nodules in the suspicious-for-follicular-neoplasm category includes

Answer 40

adenoma (majority),

follicular variant of papillary cancer (approximately 50% of the malignant nodules),

follicular cancer.

Question 41

medullary thyroid cancer cells of origin and and tumor markers

Answer 41

parafollicular or C cells,

make calcitonin more sensitive tumor marker

make carcino embryonic antigen (CEA), left in for the tumor marker but less variability may serve as an indicator tumor mass

Question 42

timing of total thyroidectomy for RET positive child

Answer 42

total thyroidectomy as early as 6 months of age.

Question 43

surgery for medullary thyroid carcinoma

Answer 43

routine central nodal dissection within the anterior triangle in the center of the neck (level 6) should be performed at the time of total thyroidectomy.

Up to 20% of patients with MTC harbor distant metastases at the time of diagnosis

Question 44

best operative approach and technique for pheochromocytoma

Answer 44

laparoscopic surgery is now the technique of first choice for resection.

Studies have shown that the laparoscopic procedure decreases postoperative morbidity, hospital stay, and expense compared with the conventional transabdominal technique for tumor removal.

Question 45

Y. is palpable RK performed first in pheochromocytoma-what is the physiologic pharmacologic reason

Answer 45

a few blocks of the beta relaxation to compensate for sympathetic alpha spasm that is still going on it can be disaster

Question 46

name the risk factors associated with Tumor recurrence after total thyroidectomy

Answer 46

age is most important

 not given in order:
 pathologic type and differentiation, 
tumor size greater than 4 cm, 
tumor extension beyond the thyroid capsule, 
nodal or distant metastases, 
age older than 45 years, 
male sex.

Question 47

Utility of preoperative thyroglobulin levels

Answer 47

Although thyroglobulin is among the most sensitive biomarkers of POSToperative disease recurrence and progression,

not good evidence that high preoperative values are predictive of future recurrence after thyroid resection

The value of preoperative thyroglobulin measurement lies in detecting those patients with differentiated thyroid cancer in whom thyroglobulin cannot be detected.

Such patients are either unable to produce thyroglobulin or have antibodies to the protein, making serial postoperative levels unreliable as a marker of recurrent disease.

This population subset should probably be treated as “high risk” simply because accepted surveillance algorithms would not be applicable.

Question 48

The threshold value for calcium, above which surgery is appropriate in primary hyperparathyroidism

Answer 48

1 mg/dL above the upper limits of normal.

Question 49

his surgery performed on patient with primary hyperparathyroidism with her presenting symptoms his hypercalcemia in the absence of renal stones

Answer 49

Hypercalciuria in the absence of renal stones is no longer regarded as indication for parathyroid surgery.

The presence of hypercalciuria (>400 mg/dL) is not considered to be an indication for surgery

Question 50

renal indication for surgery and primary hyperparathyroidism

Answer 50

A glomerular filtration rate less than 60 mL/min defines a stage 3 level of renal insufficiency.

Although patients may have reached that level of renal function due to age or comorbidity and not due to PHPT, it is regarded by many as a level of concern and an indication for surgery.

Question 51

bone density is indication for surgery for primary hyperparathyroidism

Answer 51

-2.5
but age of patient seems to be related

Surgery is indicated in peri- or postmenopausal women and in men at least 50 years who have a

T-score of –2.5 or less at any site on the bone densitometer.

Surgery is also indicated for premenopausal women and in men younger than 50 years with a Z-score of –2.5 or less on the bone densitometer.

Question 52

age of patient indication for surgery for primary hyperparathyroidism

Answer 52

Age LESS than 50 years continues to be a guideline for surgery

evidence supporting a greater risk of complications of PHPT in these individuals over time than in those older than 50 years.

Question 53

Myxedema coma definition

Answer 53

the most extreme form of hypothyroidism.

Question 54

myxedema coma cause

Answer 54

Myxedema coma occurs most commonly in elderly female patients with a history of hypothyroidism and commonly follows a precipitating event such as major surgery.

Additional precipitating factors include 
cold exposure, 
trauma, 
infection, 
stroke, 
heart failure, 
volume loss.

Question 55

myxedema coma signs and symptoms

Answer 55

somnolence, 
altered mental status, 
bradycardia, 
hypothermia, 
hypotension. 

Associated laboratory abnormalities may include
elevated thyroid-stimulating hormone,
low or undetectable free serum thyroxine
hyponatremia,
elevated creatine phosphokinase,
elevated lactate dehydrogenase,
acidosis.

Question 56

myxedema coma treatment

Answer 56

mechanical ventilation for obtunded patient,
crystalloid resuscitation for volume depletion
possibly vasopressors,
thyroid hormone replacement.

Hydrocortisone is indicated, because up to 10% of patients will have coexisting adrenal insufficiency.
hydrocortisone should be given before thyroid hormone replacement, because thyroid hormone may actually increase cortisol clearance, precipitating adrenal insufficiency.

Passive warming is indicated and includes covering the patient with blankets and keeping the patient in a warm room.

Active rewarming should be avoided because it increases oxygen consumption and promotes hypotension with circulatory collapse by causing peripheral vasodilatation. Active rewarming is indicated at core temperatures less than 28°C because of the risk of ventricular fibrillation.

Question 57

most common cause of hypercalcemia

Answer 57

Primary hyperparathyroidism

Question 58

Diagnosis of Primary hyperparathyroidism

Answer 58

elevated serum calcium WITH elevated intact parathyroid hormone (PTH) level.

low or low normal phosphate level

signs or symptoms such as fatigue, urinary frequency, kidney stones, osteoporosis/osteopenia, constipation, and bone/joint pain.

Once the diagnosis is made, technetium sestamibi (Tc99m) scanning is helpful to localize parathyroid ADENOMAS and to plan for surgery.

Question 59

laboratory findings of hypercalcemia of malignancy

Answer 59

elevated calcium level
(usually > 13 mg/dL)
AND

ELEVATED phosphate

undetectable intact PTH level ( down regulated from negative feedback)

caused by ectopic secretion of parathyroid hormone–related protein

Another cause of hypercalcemia is bone resorption, which accounts for approximately 20% of cases. The hypercalcemia is caused by bone resorption from metastatic tumor deposits, which can lead to osteoporosis.

Question 60

The differential diagnosis of diffuse thyroid enlargement includes

Answer 60

autoimmune-mediated,
compensatory,
inflammatory conditions.

Compensatory conditions, such as iodine deficiency or hormone or receptor defects, generally lack specific markers.

Question 61

autoimmune thyroid diseases

Answer 61

chronic lymphocytic (Hashimoto) thyroiditis,

Graves disease,

colloid goiter

Question 62

colloid goiter thyroid levels a

Answer 62

generally euthyroid.

Question 63

Hashimoto thyroiditis - findings, patient population, signs and symptoms

Answer 63

TSH elevated
Thyroid levels normal to low

diffuse thyroid enlargement,

most frequently in female adolescents.

CD4 T cells may be activated against thyroid antigens and recruit cytotoxic CD8 T cells, which kill thyroid cells, leading to hypothyroidism.

Initially euthyroid, many children progress to become hypothyroid.

The thyroid gland is usually a pebbly or granular consistency and may be mildly tender.

Ninety-five percent of patients with Hashimoto thyroiditis have elevated antithyroid microsomal antibodies or antithyroid peroxidase antibodies.

Question 64

Subacute (de Quervain) thyroiditis -findings, patient population, signs and symptoms

Answer 64

Because this condition is not related to an autoimmune process, markers are negative

viral inflammation of the thyroid gland.

It is more common in adults.

The thyroid becomes swollen, painful, and tender.

Mild thyrotoxicosis may result from injury to the thyroid follicles with release of thyroid hormone into the circulation.

The treatment is symptomatic and generally consists of nonsteroidal anti-inflammatory agents or corticosteroids.

Question 65

Graves disease, or diffuse toxic goiter -findings, patient population, signs and symptoms

Answer 65

thyroid level increased

immunoglobulin G class directed against components of the thyroid plasma membrane, possibly including the TSH receptor.

autoantibodies stimulate the thyroid follicles to increase iodide uptake and cyclic adenosine monophosphate production and induce the production and secretion of increased thyroid hormone.

TSH receptor antibodies are present in more than 95% of patients with active Graves disease. It is possible that infection may elicit the production of antibodies that react to the TSH receptor.

Although the basic pathogenesis of Graves disease is understood, no generally successful methods are available to correct the immunologic defect.

Current treatment includes antithyroid medications, radioactive 131Iodine ablation, or surgical resection.

Question 66

pediatric hypothyroidism - congenital

Answer 66

dysgenesis of the thyroid gland.

Two-thirds of these infants have a rudimentary gland, and complete absence of thyroid tissue is noted in the remainder.

The rudimentary gland may also be ectopic and located at the base of the tongue.

Thyroid replacement therapy is required.

There are no specific markers for this disease.

Question 67

A 59-year-old man with no prior abdominal operations is admitted to the emergency department with abdominal pain, distention, and vomiting. He has had diarrhea and facial flushing for months. The patient is taken to the operating room with a preoperative diagnosis of small bowel obstruction. During the operation, the patient is found to have innumerable small liver metastases (figure 1), a white sclerotic puckered nodule (figure 2) causing obstruction in the distal jejunum, and a 6-cm nodal mass encasing the superior mesenteric artery and superior mesenteric vein at the root of the mesentery.After resecting the small bowel mass with primary anastomosis, which of the following should be the next step?

Answer 67

Small bowel resection is indicated to relieve the bowel obstruction

resection of the primary neoplasm, even in patients with liver metastases, appears to have a favorable impact on survival.

“blind” appendectomy/right colectomy will add little in a patient with diffuse metastatic disease, especially when the primary is in the jejunum, as in this case.

Some studies suggest that debulking 70% of the tumor can improve symptoms, but this is unlikely to be achieved by hepatic resection because the metastases are typically bilobar and outside the liver, as in this patient with mesenteric disease and extensive liver involvement.

The same holds true for resection of the mesenteric disease, which may add significant morbidity.

Rather, patients with extensive liver disease and mesenteric disease may have better outcomes (and a low incidence of bowel infarction) by simply removing the primary and treating the liver disease later with chemoembolization, radiofrequency ablation, or systemically with octreotide.

This patient is likely to be on long-term octreotide therapy, which causes gallbladder sludging; therefore, cholecystectomy is indicated.

Question 68

carcinoid tumors generally arise in the

Answer 68

bronchi,
small intestine,
appendix,
rectum.

Question 69

pancreatic neo-endocrine tumors were associated with what syndromes

Answer 69

MEN1
MEN2, 
neurofibromatosis
von Hippel-Lindau disease
tuberous sclerosis

Question 70

pancreatic neuroendocrine tumor tumor marker

Answer 70

Serum chromogranin A (CGA) is a neuroendocrine secretory protein that serves as a marker of disease activity in nonfunctional PNETs and can assist in staging and monitoring. CGA may decrease in patients responding to therapy.

Question 71

effectiveness of adjuvant therapy and pancreatic neuroendocrine tumors

Answer 71

prolonged progression free survival!

combination of streptozocin and doxorubicin was associated with a combined biochemical and radiologic regression of 69%, as well as a survival benefit