Endocrinology

Question 1

1.

A 41-year-old woman presents to the emer-

gency department with palpitations. On ques-

tioning she notes heat intolerance, nervous-

ness, and insomnia. On physical examination

the physician notes a fine tremor, diffuse non-

pitting edema of the anterior lower leg, and

bulging of both of her eyes. What finding on

blood test would confirm the diagnosis?

(A) Anti-thyroid-stimulating hormone receptor

antibodies

(B) Decreased thyroid-stimulating hormone levels

(C) Increased creatine kinase-myocardial bound

(D) Increased thyroid-stimulating hormone levels

(E) Positive antinuclear antibody

Answer 1

1. The correct answer is A.

Anti-thyroid-stimulating hormone (anti-TSH) receptor

antibodies are pathognomonic for Graves’ disease, as

is suggested by this patient’s symptoms of thyrotoxico-

sis with exophthalmos and pretibial myxedema.

These antibodies mediate the disease by provok-

ing a continuous and inappropriate release of

thyroid hormone, which results in the clinical

picture described. Common modalities of treat-

ment include surgical removal of the gland, ra-

dioactive iodine gland ablation, and antithyroid

medication such as propylthiouracil.

Question 2

2.

A 17-year-old girl presents to the clinic because

she has not yet menstruated and does not have

significant breast development. Family history is

significant only for some cousins who are color

blind. The patient denies ethanol, tobacco, and

illicit drug use and sexual activity. Physical ex-

amination reveals a normal-appearing girl in no

acute distress with minimal breast development

and a lack of pubic hair. She is 168 cm (5’6”)

tall and weighs 61.2 kg (135 lb). Cardiac exami-

nation reveals no murmurs, rubs, or gallops,

with point of maximal impulse at the left mid-

clavicular line between the third and fourth in-

tercostal space. Gynecologic examination re-

veals a vagina without rugae and a cervix that is

easily visualized. There is no discharge. A urine

test is negative for β-human chorionic gonado-

tropin. Which of the following is the most likely

diagnosis?

(A) Androgen insensitivity syndrome

(B) Gonadal dysgenesis

(C) Kallmann’s syndrome

(D) Kartagener’s syndrome

(E) Pregnancy

Answer 2

2. The correct answer is C.

Kallmann’s syn-

drome is a disorder of gonadotropin-releasing

hormone (GnRH) synthesis and is associated

with primary amenorrhea without secondary

sexual characteristics due to the lack of pulsa-

tile GnRH release, which is the initiating event

of puberty. It is associated with anosmia or hy-

posmia due to olfactory bulb agenesis or hy-

poplasia. It is also associated with color blind-

ness, optic atrophy, nerve deafness, cleft palate,

renal abnormalities, cryptorchidism, and neu-

rologic abnormalities such as mirror move-

ments. Multiple mechanisms of inheritance

have been observed, including autosomal re-

cessive, autosomal dominant, and X-linked.

Treatment is with oral contraceptives. To be-

come pregnant, patients with Kallmann’s syn-

drome require further treatment with a GnRH

pump. This syndrome would account for this

patient’s symptoms of amenorrhea and lack of

secondary sexual characteristics.

Question 3

3.

A 26-year-old man presents with increased

thirst, urinary frequency, and nocturia over the

past several months. Physical examination is

unremarkable. Twenty-four-hour urine osmo-

larity is <300 mOsm/L. A fl uid deprivation test

does not result in an increased urine osmolar-

ity. Administration of 0.03 μg/kg of desmopres-

sin results in a urine osmolarity of 450

mOsm/L after 2 hours. Which of the following

is the most likely diagnosis?

(A) Central diabetes insipidus

(B) Diabetes mellitus

(C) Nephrogenic diabetes insipidus

(D) Psychogenic polydipsia

(E) Syndrome of inappropriate secretion of ADH

Answer 3

3. The correct answer is A.

Central diabetes in-

sipidus (DI) is a defi ciency of production of

ADH in the posterior pituitary. ADH acts in

the distal nephron and collecting tubule of the

kidney to concentrate the urine and reabsorb

water. Central DI can be a primary condition

due to a genetic disorder or may be idiopathic;

it can also be a secondarily acquired disorder

due to trauma, neoplasm, infection, infl

ammatory conditions, and toxins. A deficiency in

ADH leads to decreased water reabsorption in

the kidney that results in hypernatremia and

increased volumes of dilute urine.

Question 4

4.

A 6-year-old boy is brought to his pediatrician

for a routine check-up. He has not been seen by

a physician for the past 3 years. Recently, he has

developed some patchy areas of hair loss on his

scalp. The mother also notes he has had many

colds over the past year. She says he has devel-

oped normally, although he started walking later

than her other two children. On physical exami-

nation his wrists appear enlarged, and he has

bowing of the forearms and legs. X-ray of the

boy’s legs is shown in the image. Laboratory tests

show a calcium level of 7.1 mg/dL, phosphate

of 1.8 mg/dL, and intact parathyroid hormone

of 130 pg/mL (normal: 10–65 pg/mL). Vitamin

D level is normal. Treatment with vitamin D

does not correct the patient’s hypocalcemia.

Which of the following disorders best explains

this patient’s findings?

(A) Dietary vitamin D deficiency

(B) Hypoalbuminemia

(C) Primary hyperparathyroidism

(D) Pseudohypoparathyroidism

(E) Vitamin D-resistant rickets

Answer 4

4. The correct answer is E.

This patient’s presen-

tation is consistent with rickets. Rickets is a dis-

order of bone mineralization that can be due

to hypocalcemia or hypophosphatemia. Hy-

pocalcemic rickets is typically due to a defi

ciency of vitamin D from dietary insufficiency,

lack of exposure to sunlight, lack of enzymes to

convert vitamin D to active metabolites, or

end-organ resistance to vitamin D. In this pa-

tient with normal vitamin D levels, it is one of

the later etiologies, and treatment with exoge-

nous vitamin D will not correct the hypocalce-

mia. Clinical presentation may include tetany,

convulsions, alopecia, and skeletal abnormali-

ties. Skeletal fi ndings include widened growth

plates, frontal bossing, enlargement of the

wrists, bowing of the distal forearm, lateral

bowing of the femur and tibia, and delay in

closure of the fontanelles. Children may pre-

sent with dental enamel hypoplasia, delay in

motor milestones, and frequent infectious dis-

eases. Laboratory fi ndings will include hypocal-

cemia, hypophosphatemia, and secondary hy-

perparathyroidism.

Question 5

5.

A 53-year-old woman presents to the clinic

with complaints of headache and blurred vi-

sion for the past several months. She also says

her family has commented that her face “looks

different,” and her nose is bigger than it used

to be. In addition, she says her shoes feel

tighter. On physical examination she has

coarse facial features with a prominent mandi-

ble and widely spaced incisors. MRI of the

brain reveals a mass in the pituitary. This pa-

tient may be at increased risk of developing

which of the following malignancies?

(A) Colon cancer

(B) Hepatocellular carcinoma

(C) Lung cancer

(D) Malignant brain tumor

(E) Pancreatic adenocarcinoma

Answer 5

5. The correct answer is A.

This patient has acro-

megaly, a condition caused by excessive levels of

GH, most commonly due to a pituitary ade-

noma. Blurred vision is due to compression of

the optic chiasm by the pituitary mass, and pa-

tients may also exhibit frontal bossing, mandibu-

lar growth, coarsened facial features, and in-

creased hand and foot size due to bony

overgrowth and soft tissue swelling. Patients with

acromegaly may be at increased risk for develop-

ing colonic polyps and colonic malignancy. Pa-

tients with acromegaly are also at increased risk

for coronary artery disease, cardiomyopathy, hy-

pertension, DM, and sleep apnea.

Question 6

6.

A 13-year-old boy is brought to the pediatrician

by his mother because of increasing body hair.

Several months earlier he had been diagnosed

with 17 α-hydroxylase defi ciency and treated

with hydrocortisone. Physical examination re-

veals an overweight boy with a moderate

amount of both chest and genital hair, and

some facial hair growth. His physical examina-

tion is otherwise unremarkable. Which of the

following is the best treatment for this patient?

(A) Add cosyntropin

(B) Add dexamethasone

(C) Add spironolactone

(D) Increase hydrocortisone

(E) Keep the current dose of hydrocortisone

Answer 6

6. The correct answer is B.

In individuals with

17 α-hydroxylase defi ciency, ACTH secretion is

elevated secondary to decreased cortisol levels.

The goal of treatment with hydrocortisone is

not only to replenish cortisol, but also to sup-

press ACTH secretion. The reason for this is

that if ACTH remains high, it will stimulate

androgen production and lead to premature vi-

rilization and growth plate ossification. Nightly

dexamethasone treatments may be necessary to

more completely suppress ACTH secretion in

adolescents.

Question 7

7.

A 72-year-old man with atrial fibrillation pre-

sents with complaints of fatigue and feeling

cold. He also notes constipation and dry skin.

His daughter states he has seemed more forget-

ful over the past several months. His tempera-

ture is 37.3°C (99.1°F), heart rate is 48/min,

and blood pressure is 130/82 mm Hg. Cardiac

examination shows bradycardia but normal

rhythm, and normal S1 and S2 with no mur-

murs; the lungs are clear to auscultation bilat-

erally and the abdomen is soft and nontender.

The patient’s extremities are cool and puffy

with dry, coarse skin. Laboratory studies show a

thyroid-stimulating hormone level of 32 μU/L,

free thyroxine of 0.3 ng/dL, and total tri-

iodothyronine of 30 ng/dL. What medication is

the patient likely taking for his atrial fibrillation?

(A) Amiodarone

(B) Flecainide

(C) Lithium

(D) Methimazole

(E) Sotalol

Answer 7

7. The correct answer is A.

The patient is pre-

senting with signs and symptoms consistent

with hypothyroidism which include fatigue,

weakness, cold intolerance, dry skin, constipa-

tion, bradycardia, coarse hair and skin, and

puffy, cool extremities. Hypothyroidism can be

a primary disorder of the thyroid gland, a sec-

ondary disorder due to defi cient production of

TSH by the pituitary, or a tertiary disorder due

to defi cient production of thyrotropin-releasing

hormone by the hypothalamus. This patient’s

laboratory results confi rm a diagnosis of pri-

mary hypothyroidism because the thyroid hor-

mone levels are low in the presence of an ele-

vated TSH. Amiodarone, an antiarrhythmic

agent commonly used in atrial fibrillation, can

cause hypothyroidism by inhibiting production

of triiodothyronine, by direct toxicity to thyroid

follicular cells, and by effects due to amio-

darone’s iodine content.

Question 8

8.

A 45-year-old woman with chronic alcohol

abuse admitted 3 days ago for nausea and se-

vere diarrhea now complains of perioral and

finger tingling. She was admitted for hydration

after 1 week of severe watery diarrhea. She has

been receiving intravenous hydration and dex-

trose but has not been able to take oral nutri-

tion secondary to continued nausea. Her blood

pressure is 130/74 mm Hg, pulse is 68/min,

and respiratory rate is 16/min. She is afebrile.

Physical examination is signifi cant for facial

twitching on percussion of her facial nerve just

anterior to the ear, as well as the induction of

carpal spasm after the infl ation of a blood pres-

sure cuff on her arm. Which of the following is

most likely to have caused these findings?

(A) Azotemia

(B) Hypernatremia

(C) Hypomagnesemia

(D) Hypophosphatemia

(E) Hypouricemia

Answer 8

8. The correct answer is C.

This patient is display-

ing classic signs of hypocalcemia, including hy-

perexcitability of her facial nerve (Chvostek’s

sign), induced carpal spasm (Trousseau’s sign),

and tingling of the extremities and lips. Calcium

homeostasis is a complicated process involving

PTH, vitamin D, albumin, and numerous elec-

trolytes. Acquired hypoparathyroidism is the

most common form of true hypocalcemia, most

often occurring transiently after thyroid surgery

or after the removal of a parathyroid adenoma.

Occasionally, hypomagnesemia can produce

hypocalcemia by decreasing both the body’s

production of PTH and its sensitivity to the hor-

mone. In this case, it is likely that the patient

became magnesium depleted from her course

of watery diarrhea, likely baseline poor nutri-

tional status, and alcohol abuse.

Question 9

9.

A 17-year-old girl has never had a menstrual

period. On physical examination, she has mini-

mal breast development and no axillary or pu-

bic hair. She is color blind and has had a di-

minished sense of smell since birth. Laboratory

evaluation would most likely reveal which of

the following?

(A) A

(B) B

(C) C

(D) D

(E) E

Answer 9

9. The correct answer is A.

The patient’s findings

are consistent with Kallmann’s syndrome, a con-

genital defi ciency of GnRH synthesis in the hy-

pothalamus. Women present with primary

amenorrhea and failure to develop secondary

sexual characteristics. Laboratory evaluation will

show low or absent levels of GnRH. Because

GnRH is required for release of gonadotropins

from the anterior pituitary, there will also be di-

minished levels of luteinizing hormone (LH)

and follicle-stimulating hormone (FSH). This

syndrome is associated with anosmia or hypos-

mia due to hypoplasia or agenesis of the olfac-

tory bulb, color blindness, cleft palate, renal dis-

orders, and nerve deafness.

Question 10

10.

A 28-year-old woman presents to her gynecolo-

gist for her annual examination. She mentions

that she and her husband have been trying to

conceive for 9 months without success and that

her menstrual cycles have become irregular.

Her gynecologist suggests that she and her hus-

band continue to try to conceive and that the

woman return in 3 months for some laboratory

studies if she still has not become pregnant. In

the interim, a routine visit to the ophthalmolo-

gist reveals bitemporal hemianopsia. Which of

the following is the most likely cause of this woman’s

infertility?

(A) Ectopic endometrial tissue

(B) Failure of implantation

(C) Hostile cervical mucus

(D) Ovarian unresponsiveness to gonadotropins

(E) Suppression of ovulation

Answer 10

10. The correct answer is E.

This woman has a pituitary prolactinoma, which is

associated with amenorrhea, infertility, and

galactorrhea. Prolactin inhibits the secretion of

gonadotropins and suppresses ovulation. Dopamine is

used to suppress prolactin and thus restore fertility.

Question 11

11.

A 4-year-old boy is brought to the pediatrician

by his worried mother. She notes that he “uri-

nates 10 times a day and is always drinking wa-

ter.” She also reports that despite eating more

than either of his brothers did at the same age,

he is not gaining any weight. Which of the fol-

lowing human leukocyte antigen (HLA) types

is associated with the most likely diagnosis for this

child?

(A) HLA-B27

(B) HLA-B51

(C) HLA-D11

(D) HLA-DR2

(E) HLA-DR3

Answer 11

11. The correct answer is E.

Given that type 1

DM is most likely an autoimmune disease, it is

not surprising that it is associated with certain

HLA types. HLA-DR3 is associated with type 1

DM and is found in about 4% of patients. It is

also associated with systemic lupus erythemato-

sus and Graves’ disease.

Question 12

12.

A 48-year-old woman presents to her primary

care physician because of 2 weeks of neck pain.

The pain is constant and sharp (rated at 10 of

10) and is felt in the anterior portion of her
neck. She also notes several weeks of loose

stools and fatigue. Past medical history is signif-

icant for a viral upper respiratory infection

about 1 month ago. She has a temperature of

37.9°C (100.2°F), heart rate of 96/min, and

blood pressure of 136/82 mm Hg. On neck ex-

amination there is diffuse enlargement of the

thyroid and it is exquisitely tender to even mild

palpation. Laboratory tests show a total tri-

iodothyronine level of 280 ng/dL, total thyrox-

ine of 25 μg/dL, and thyroid-stimulating hor-

mone of 2 μU/mL (normal: 0.4–4 μU/L).

Which of the following is the most likely diagnosis?

(A) Acute infectious thyroiditis

(B) Drug-induced thyroiditis

(C) Hashimoto’s thyroiditis

(D) Riedel’s thyroiditis

(E) Subacute granulomatous thyroiditis

Answer 12

12. The correct answer is E.

Painful thyroiditis

limits the differential to subacute granuloma-

tous thyroiditis, acute infectious thyroiditis, and

palpation- or trauma-induced thyroiditis. In

this case the diagnosis is subacute granuloma-

tous thyroiditis, otherwise known as de Quer-

vain’s thyroiditis, which typically follows an

acute viral illness, typically an upper respira-

tory infection. Infl ammation leads to destruc-

tion of thyroid follicles, causing release of thy-

roid hormone stores, leading to a transient

period of hyperthyroidism until the stores are

exhausted. There may be a transient period of

hypothyroidism that follows, but as infl

ammation subsides, the follicles will regenerate and

the patient will return to a euthyroid state. Be-

cause of the increased thyroid hormone in the

serum, the TSH level will be low due to nega-

tive feedback on the pituitary.

Question 13

13.

A 74-year-old woman is brought to the emer-

gency department by her daughter. The daugh-

ter states that her mother lives alone and has

no signifi cant medical problems. She says that

she last saw her mother a month prior, before

she left on an extended business trip. When

she returned, she found her mother appeared

restless and very nervous. She also appeared to

have lost a noticeable amount of weight. The

patient told her daughter that she had been

having increased frequency of bowel move-

ments, and felt like her heart was beating “fast

and funny,” and that she felt like she might be

coming down with a cold. Initial evaluation in

the emergency department reveals sinus tachy-

cardia and a painful, enlarged thyroid. Which

of the following is the most likely etiology of

her symptoms?

(A) Autoimmune thyroiditis

(B) Graves’ disease

(C) Medication-induced hyperthyroidism

(D) Subacute granulomatous thyroiditis

(E) Toxic multinodular goiter

Answer 13

13. The correct answer is D.

This patient is pre-

senting with the symptoms of subacute granu-

lomatous thyroiditis. Thyroiditis usually pres-

ents initially with symptoms of hyperthyroidism

or thyrotoxicosis, which is then followed by hy-

pothyroidism. Some patients also complain of

malaise or symptoms of an upper respiratory

tract infection. This patient is presenting with

several of the symptoms of hyperthyroidism,

notably nervousness, palpitations, weight loss,

and increased frequency of bowel movements.

Other symptoms include heat intolerance and

insomnia. Signs of hyperthyroidism include

warm, moist skin, the presence of a goiter, car-

diac arrhythmia (sinus tachycardia or atrial fi

brillation), and hyperactive refl exes. The key to

understanding the etiology of this patient’s hy-

perthyroidism is that she has a tender, enlarged

thyroid.

Question 14

14.

An 18-year-old woman presents to the emer-

gency department with acute mental status

changes, rapid and deep breathing, abdominal

pain, and vomiting. On examination she is tac-

hypneic and tachycardic, her abdomen is soft

and nontender, and her mucous membranes

are dry. Laboratory values are notable for a po-

tassium level of 5.5 mEq/L, bicarbonate of 12

mEq/L, and serum glucose of 400 mg/dL.

Which of the following is the most appropriate

strategy during the first 24 hours?

(A) Diuresis and ventilatory support

(B) Diuresis, strict potassium restriction, and insulin

(C) Intravenous fluids, insulin, and potassium

(D) Intravenous fluids, insulin, and strict potassium restriction

E) Intravenous fluids, loop diuretic, and potassium

Answer 14

14. The correct answer is C.

This patient is in a

state of DKA. Lack of insulin is the primary

disorder, and insulin administration will allow

glucose to enter cells and reverse the meta-

bolic starvation that is driving the production

of ketoacids. It is also important to immediately

administer intravenous fl uids because the pa-

tient is severely dehydrated. Finally, even

though she is hyperkalemic, her potassium lev-

els will decrease rapidly once the insulin is

given because it will cause the potassium to

enter the cells. Therefore, it is important to

give additional potassium to ensure that the pa-

tient does not become hypokalemic.

Question 15

15.

A 56-year-old woman presents to the outpatient

clinic for a routine visit. On physical examina-

tion a 1-cm nodule is palpated in her thyroid.

Her physical examination is otherwise unre-

markable. Her heart rate is 70/min and regular,

blood pressure is 126/82 mm Hg, and tempera-

ture is 36.7°C (98.0°F). Which of the follow-

ing is a poor prognostic indicator for the thyroid

nodule?

(A) Female gender

(B) Hoarseness

(C) Palpitations

(D) Patient age of 56 years

(E) Slow growth of nodule

(F) Tender nodule

Answer 15

15. The correct answer is B.

Hoarseness generally

implies vocal cord impairment due to tumor

involvement of the recurrent laryngeal nerve.

This suggests a malignant tumor that has ex-

tended beyond the thyroid and invaded local

structures. This is a poor prognostic indicator.

Local invasion is particularly common with

papillary carcinoma.

Question 16

16.

A 26-year-old man with a history of kidney

stones presents with 1 week of severe burning

epigastric pain. He also notes several days of di-

arrhea and nausea but denies emesis or fever.

His family history is remarkable for a paternal

uncle with pancreatic cancer. His temperature

is 37°C (98.6°F), heart rate is 88/min, respira-

tory rate is 16/min, and blood pressure is

125/85 mm Hg. Abdominal examination is

significant for tenderness in the mid-epigastrium.

Upper endoscopy reveals a 1-cm ulceration in

the fi rst part of the duodenum. This is the third

episode of confi rmed peptic ulcers in this pa-

tient. Laboratory studies show:

Na+: 140 mEq/L

K+: 4.9 mEq/L

Cl−: 105 mEq/L

HCO3−: 25 mEq/L

Ca2+: 12.0 mg/dL

PO4: 1.4 mg/dL

Mg2+: 2.0 mg/dL

Blood urea nitrogen: 10 mg/dL

Creatinine: 1.0 mg/dL

Glucose: 87 mg/dL

Which of the following is most likely to be

found in this patient?

(A) Medullary thyroid carcinoma

(B) Papillary thyroid carcinoma

(C) Pheochromocytoma

(D) Prolactinoma

(E) Squamous cell lung cancer

Answer 16

16. The correct answer is D.

This patient’s current

symptoms and past medical and family histo-

ries are highly suspicious for type I multiple

endocrine neoplasia (MEN type 1), an auto-

somal dominant condition consisting of pan-

creatic tumors, hyperparathyroidism, and pitu-

itary adenomas. Zollinger-Ellison syndrome

causes recurrent peptic ulcers due to excessive

gastrin secretion by a gastrinoma, either in the

pancreas or elsewhere in the gastrointestinal

tract. Hyperparathyroidism causes hypercalce-

mia, hypophosphatemia, and elevated levels of

serum PTH. The most common pituitary tumor

found in MEN type 1 is prolactinoma, but other

tumors include ACTH-secreting and GH-secret-

ing adenomas.

Question 17

17.

An obese 18-year-old woman is brought to the

emergency department by her mother, who

noted that she had been lethargic all day, and

suffered a brief, seizure-like episode. One

month earlier, the patient had been started on

medication for type 2 DM. Lactic acid levels

are normal. Which of the following medica-

tions most likely played a role in the patient’s

current presentation?

(A) A statin

(B) A sulfonylurea

(C) A thiazolidinedione

(D) An α-glucosidase inhibitor

(E) Metformin

Answer 17

17. The correct answer is B.

Sulfonylureas (glipi-

zide, glyburide) treat type 2 DM by increasing

the amount of insulin secretion. The obvious

potential adverse effect of this is hypoglycemia.

Weight gain is another adverse effect.

Question 18

18.

A 75-year-old woman is brought to the emer-

gency department after being found unrespon-

sive at her home. She was last spoken to by her

daughter on the phone 24 hours earlier, at

which time she complained of chills, lethargy,

and weakness. The woman has had a heart at-

tack in the past, she has high blood pressure,

and she had a total thyroidectomy performed a

decade ago for cancer. The daughter had re-

turned from several months out of town, and is

unsure if the patient was taking her medica-

tions. Her temperature is 34.9°C (94.9°F),

pulse is 48/min, blood pressure is 110/65 mm

Hg, oxygen saturation is 99% on 100% oxygen,

and glucose is 85 mg/dL. On examination the

patient is unresponsive, obese, and edematous

with periorbital edema. Her cardiac and pul-

monary examinations are normal. CT of the

head reveals no signs of trauma or increased

intracranial pressure, and ECG demonstrates

no acute ischemic changes. Blood is drawn for

laboratory testing. Which of the following is

most appropriate for treating the patient’s mental

status change?

(A) Aspirin

(B) Glucagon

(C) Hemodialysis

(D) Levothyroxine

(E) Metoprolol

(F) Norepinephrine

Answer 18

18. The correct answer is D.

It is highly likely that

this patient has myxedema coma. She has a

history of thyroidectomy, making her depen-

dent on thyroid hormone supplementation,

and she may have run out of medications.

Myxedema coma most often presents as de-

pressed mental status and hypothermia, and

can also involve bradycardia, hypotension, hy-

poglycemia, and hyponatremia. It is often

brought on by a precipitating illness, ischemic

insult, or administration of sedatives. Manage-

ment includes blood thyroid function tests

prior to administration of levothyroxine and tri-

iodothyronine.

Question 19

19.

A 52-year-old African-American woman with

type 2 diabetes mellitus (DM) presents to her

physician’s offi ce and states that she has been

“feeling lousy in the morning.” She notes that

she reliably checks her blood glucose levels,

and is frustrated at the fact that she often has a

blood sugar level in the 120s at night, followed

by a level in the 170s to 180s the following

morning. The patient’s primary care physician

increased her nightly dose of neutral protamine

Hagedorn insulin 1 month ago, but her morn-

ing glucose levels have only become more ele-

vated. She has recently begun to limit her car-

bohydrate intake at night, with no effect. This

patient’s morning hyperglycemia might most

likely be alleviated by which of the following?

(A) Decreasing neutral protamine Hagedorn insulin at night

(B) Increasing neutral protamine Hagedorn insulin at night

(C) Increasing neutral protamine Hagedorn insulin in the morning

(D) Increasing regular insulin at night

(E) Increasing regular insulin in the morning

Answer 19

19. The correct answer is A.

This patient’s morn-

ing hyperglycemia may be her body’s reaction

to nocturnal hypoglycemia. Reactive hypergly-

cemia following hypoglycemia is known as the

Somogyi effect. To approach this question, the

actions of regular and neutral protamine Hage-

dorn (NPH) insulin should be understood.

Compared to NPH, regular insulin has a

shorter duration of onset, a peak action at 3 to

4 hours (vs. 6–8 hours for NPH), and a shorter

overall duration (6–8 hours for regular insulin

vs. 18–20 hours for NPH). If the dose of NPH

insulin given at night causes the morning glu-

cose to be too low, then the body may release

stress hormones in response. The release of

these stress hormones then causes the morning

glucose to be high. The correct response is to

decrease insulin at night.

Question 20

20.

A 26-year-old G1P0 woman at 12 weeks’ gesta-

tion presents to her obstetrician for her first

visit. Her pregnancy thus far has been notable

only for some mild nausea and vomiting that

lasted throughout her fi rst trimester. She re-

ports feeling overly tired lately and very weak.

Her past medical history is signifi cant for perni-

cious anemia. On physical examination she is

an anxious-appearing, thin woman. Her blood

pressure is 130/85 mm Hg, heart rate is 115/

min, and respiratory rate is 18/min. Fetal heart

tones are present at 135/min. The uterine fun-

dus is at 12 cm. The woman has a diffuse, non-

tender goiter, a resting tremor, and poor global

muscle strength. Which is the most likely

mechanism underlying this woman’s condition?

(A) Autoantibodies against thyroid-stimulating

hormone receptor

(B) Iodine overdose

(C) The mechanism of this disease is unknown

(D) Uncontrolled cell growth

(E) Viral infection

Answer 20

20. The correct answer is A.

This woman likely has

Graves’ disease, an autoimmune disease in

which antibodies against the TSH receptor acti-

vate the thyroid into overproduction of thyrox-

ine. It is associated with other autoimmune dis-

orders such as pernicious anemia. Her fetus is at

risk of developing thyrotoxicosis because thy-

roid-stimulating autoantibodies can cross the

placenta and activate the fetal thyroid. Hence,

fetal heart rate and maternal thyroid-stimulating

immunoglobulin levels should be monitored

during the pregnancy.

Question 21

21.

A 60-year-old woman recently diagnosed with

type 2 DM complains of daily headaches and

double vision that have gradually worsened

over the previous month. An MRI shows a

large pituitary adenoma. Which of the follow-

ing is most likely being secreted by this tumor?

A) ACTH

(B) Growth hormone

(C) Luteinizing hormone

(D) Prolactin

(E) Thyroid-stimulating hormone

Answer 21

21. The correct answer is B.

GH has both direct

effects, and effects mediated by release of insu-

lin-like growth factor-1 (IGF-1) from the liver.

Most of the long-term growth promoting ef-

fects of GH are mediated by IGF-1. GH itself

acts as an insulin antagonist, which may ac-

count for the existence of a feedback mecha-

nism that inhibits GH release in response to a

high-glucose meal in healthy persons. It also

explains the high incidence of DM in patients

with GH-secreting pituitary tumors, such as

this patient.

Question 22

22.

A 14-year-old boy presents at the pediatric

clinic for a routine check-up. The patient had

developed end-stage renal disease over the pre-

vious 2 years, and was successfully treated with

a renal transplant 6 months prior. Since his op-

eration, he has developed purple striae on his

back and arms, central obesity, and an increas-

ingly round face. During the subsequent blood

analysis, which of the following results would

be most likely?

A) A

(B) B

(C) C

(D) D

(E) E

Answer 22

22. The correct answer is A.

Given his history of

recent renal transplantation and the symptoms

of Cushing’s syndrome, it is most likely that

this child is currently taking corticosteroids as

a means of immunosuppression. Exogenous

corticosteroids such as prednisolone and dex-

amethasone have similar effects to those of cor-

tisol, and the high levels used in posttransplant

immunosuppression cause feedback suppres-

sion of ACTH release from the pituitary, as

well as cushingoid symptoms. ACTH suppres-

sion causes suppression of endogenous cortisol

production from the adrenal. This explains the

seemingly paradoxical laboratory findings of

hypothalamic-pituitary-adrenal axis suppres-

sion in the setting of hyperglucocorticoid

symptoms (although note that specific exoge-

nous glucocorticoids occasionally may cross-

react with some cortisol assays).

Question 23

23.

A 64-year-old man presents to the emergency

department after a motor vehicle crash and receives

a CT of the abdomen that shows a finding

of a unilateral mass in the left adrenal

gland. He is unharmed from the accident, feels

well, and has never smoked. His blood pressure

is 155/90 mm Hg, deep tendon reflexes are 3/4, and

muscle strength is 4/5. Laboratory studies show:

Na+: 150 mEq/L

K+: 3.0 mEq/L

Cl−: 105 mEq/L

HCO3−: 36 mEq/L

Plasma renin activity is also decreased. Which

of the following is most likely to be increased?

(A) Aldosterone

(B) Anion gap

(C) Carcinoembryonic antigen

(D) Prostate-specific antigen

(E) Troponin

Answer 23

23. The correct answer is A.

The patient is pre-

senting signs and symptoms of primary hyper-

aldosteronism: hypertension, hyperreflexia,

weakness, hypernatremia, hypokalemia, alkalo-

sis, and decreased plasma renin suggest the

unilateral mass seen on CT is an adrenal ade-

noma hypersecreting mineralocorticoids.

Question 24

24.

A 28-year-old patient with known Addison’s dis-

ease presents with abdominal pain and is hy-

potensive to a systolic pressure of 88 mm Hg.

He has a 2-week history of progressively worse

nonproductive dry cough, sore throat, malaise,

and headache. He has not checked his temper-

ature at home but complains of constant chills.

Which of the following is the best initial management?

(A) Azithromycin

(B) Check serum glucose

(C) Hydrocortisone

(D) Intravenous fluids

(E) X-ray of the chest

Answer 24

24. The correct answer is D.

Intravenous fluids

should fi rst be administered prior to any other

treatment. Although hydrocortisone is indi-

cated to prevent an adrenal crisis in patients

with primary adrenal insufficiency,

Airway, Breathing, and Circulation (the “ABC’s”) must

first be addressed. As the patient is able to

speak comfortably, his airway and breathing

are intact and stable. However, the systolic

blood pressure of 88 mm Hg requires fl

uid resuscitation.

Question 25

25.

A generally healthy 74-year-old woman who re-

cently moved into the area visits the physician’s

office for her first well-visit. She states that her

previous doctor had been treating her with

propylthiouracil (PTU) for subclinical hyperthyroidism,

but that her prescription ran out several months ago.

Laboratory studies reveal that her free thyroxine

and triiodothyronine levels are normal, but her thyroid

stimulating hormone is depressed. PTU therapy is most

important in this patient to prevent the development of

which disorder?

(A) Cardiac dysrhythmias

(B) Hypothyroidism

(C) Pretibial myxedema

(D) Thyroid cancer

(E) Thyroid storm

Answer 25

25. The correct answer is A.

Patients with subclin-

ical hyperthyroidism who are >60 years old

have a three- to fi vefold increased risk of devel-

oping atrial fi brillation. There is some contro-

versy regarding the best way to treat subclinical

hyperthyroidism, but antithyroid medications

such as PTU are commonly used. In addition

to cardiac dysrhythmias, there is an increased

risk of bone density abnormalities in patients

who are noted to have subclinical hyperthyroidism.

Question 26

26.

A 58-year-old woman presents to her physician

because of neck discomfort and difficulty

swallowing. She first began to have difficulty with

swallowing solids 2 years ago, but the problem

is getting progressively worse. She denies

hemoptysis, hematemesis, abdominal pain, or

change in bowel habits. She is a nonsmoker

and past medical history is signifi cant only for

mild hypertension. Her temperature is 36.9°C

(98.4°F), heart rate is 72/min, and blood pres-

sure is 132/78 mm Hg. She has an asymmetri-

cally enlarged thyroid gland that is particularly

firm on the right, with poorly palpable borders.

Laboratory evaluation reveals a free thyroxine

level of 4.1 ng/dL and thyroid-stimulating hor-

mone of 5 μU/mL. Based on the results of a ra-

dioisotope scan and a fi ne needle aspiration bi-

opsy, the physician decides to perform surgery.

For which of the following is the patient at in-

creased risk postoperatively?

(A) Bone metastases

(B) Hypercalcemia

(C) Hypocalcemia

(D) Hypophosphatemia

(E) Pheochromocytoma

Answer 26

26. The correct answer is C.

This patient’s presen-

tation, clinical examination, and laboratory

fi ndings are consistent with thyroid carcinoma,

likely follicular type. She should be treated

with a thyroidectomy, followed by radioactive

iodine a few months later to destroy any re-

maining tumor cells. The anatomic proximity of

the parathyroid glands and their blood supply to

the thyroid gland puts her at risk of iatrogenic hy-

poparathyroidism after her thyroidectomy, lead-

ing to hypocalcemia and hyperphosphatemia.

She should be monitored for this outcome and

treated appropriately.

Question 27

27.

A 49-year-old woman presents to her physi-

cian’s office with a long-standing history of

polydipsia, polyuria, central obesity, and hyper-

lipidemia. She is currently taking metformin, a

sulfonylurea, and an angiotensin-converting

enzyme (ACE) inhibitor. ACE inhibitors are

most beneficial in preventing or slowing the

progression of which of the following diabetic

complications?

(A) Diabetic ketoacidosis

(B) Diabetic nephropathy

(C) Diabetic neuropathy

(D) Diabetic retinopathy

(E) Peripheral vascular disease

Answer 27

27. The correct answer is B.

ACE inhibitors such

as captopril have been shown to decrease blood

pressure and prevent and slow the progression

of diabetic nephropathy in patients with DM.

It is believed that ACE inhibitors play a reno-

protective role by reducing glomerular filtra-

tion rate and reducing macroproteinuria.

Question 28

28.

A 42-year-old woman presents to her physician

with complaints of fever (38.2°C [100.8°F])

and mild-to-moderate anterior neck pain. On

examination the physician finds her to be

tachycardic and sweating, and to have an ex-

quisitely tender thyroid gland. Her blood work

shows a depressed thyroid-stimulating hormone

level and increased free thyroxine. Which of

the following is the most appropriate treatment

at this time?

(A) Acetaminophen

(B) Ibuprofen

(C) Levothyroxine

(D) Prednisone

(E) Radioactive iodine

Answer 28

28. The correct answer is B.

This patient presents

with the classic symptoms of subacute (de Quer-

vain’s) thyroiditis, which is typically tender to

palpation. Also, increased TSH and thyroxine indicate

that the patient also has primary hyper-

thyroidism. It is most commonly due to viral

infection of the thyroid gland and is self-lim-

ited in 90% of cases. Other causes of hyperthy-

roidism, such as Graves’ disease, do not lead to

anterior neck pain. Nonsteroidal anti-infl

ammatory drugs are the most appropriate treat-

ment at this time.

Question 29

29.

A 24-year-old woman presents to her gynecolo-

gist’s office because of irregular menstrual cy-

cles. She is otherwise healthy and takes no
medication. She began menstruating at the age

of 12 years and has never had regular intervals

between cycles, which range from 5 weeks to 3

months. She is not sexually active. On physical

examination she is overweight with moderate

acne on her forehead and chin. Her blood

pressure is 115/85 mm Hg, heart rate is 95/

min, and respiratory rate is 18/min. Pelvic ex-

amination reveals a smooth, nontender, appro-

priately sized uterus and slightly enlarged ova-

ries bilaterally. Laboratory studies are ordered.

Which of the following are the most likely laboratory results?

A) A

(B) B

(C) C

(D) D

Answer 29

29. The correct answer is B.

This woman displays

several characteristics of polycystic ovarian syn-

drome (PCOS), including high estrogen and

androgen levels, resulting in virilization (hair

growth and acne) and menstrual irregularities.

Increased levels of androgens lead to high estro-

gen levels, which suppress FSH and lead to in-

creased LH levels. PCOS is commonly associ-

ated with peripheral insulin resistance, which

may improve with the use of metformin.

Question 30

30.

A 61-year-old obese man with a history of

chronic alcohol abuse is diagnosed with type 2

DM. In addition to diet modification and exer-

cise, his physician recommends he begin ther-

apy with a hyperglycemic agent. Several days

after starting therapy, his wife comes home

from work and finds him sitting on the couch

staring into space and breathing rapidly. When

she speaks to him, she fi nds he is quite con-

fused, and immediately takes him to the emer-

gency department. Arterial blood gas analysis

shows:

pH: 7.2

HCO3−: 19 mEq/L

Partial carbon dioxide pressure: 32 mm Hg

Partial oxygen pressure: 80 mm Hg

Lactate: 6 mmol/L

Which of the following drugs is most likely re-

sponsible for this patient’s symptoms?

(A) Acarbose

(B) Glipizide

(C) Insulin

(D) Metformin

(E) Rosiglitazone

Answer 30

30. The correct answer is D.

This patient was most

likely started on metformin, which is the first-

line medication used to treat type 2 DM in the

absence of contraindications. Metformin is a

good choice for obese patients because unlike

other hyperglycemic agents, which can lead to

weight gain, metformin is not associated with

weight gain. It works by inhibiting hepatic glu-

coneogenesis and sensitizes peripheral tissues to

insulin. One of the adverse effects of metformin,

however, is lactic acidosis, which is what this pa-

tient has. He is at increased risk for this rare

event because of his history of alcohol abuse.

Other patients in whom metformin should be

avoided or used with care because of the risk of

lactic acidosis include elderly patients and those

with renal insuffi ciency, liver disease, or heart

disease.

Question 31

31.

A moderately overweight 34-year-old woman

presents to the emergency department with ex-

cessive sweating, fl ushing, tachycardia, and

nervousness. Presuming that she might be suf-

fering from thyrotoxicosis, the physician checks

her blood levels of thyroid hormones, and finds

that her free thyroxine and triiodothyronine

levels are elevated, while her thyroid-stimulat-

ing hormone is decreased. Her radioactive io-

dine uptake test shows a complete absence of

iodine uptake. Which of the following is the

most likely diagnosis?

(A) Factitious thyrotoxicosis

(B) Graves’ disease

(C) Thyroid-stimulating hormone-secreting pi-

tuitary tumor

(D) Toxic adenoma

(E) Toxic multinodular goiter

Answer 31

31. The correct answer is A.

Factitious thyrotoxi-

cosis involves the administration of exogenous

thyroid hormone, commonly in an attempt to

lose weight. The distinguishing factor between

factitious thyrotoxicosis and the other choices

is the result of the radioactive iodine uptake

test. By exhibiting no uptake, it shows that the

administration of exogenous thyroxine and tri-

iodothyronine has downregulated uptake by

the thyroid gland. The other conditions involve

primary or secondary overactivity of the thyroid

gland, thereby resulting in increased levels of

triiodothyronine and thyroxine.

Question 32

32.

A 38-year-old woman presents with several

months of decreased libido and a 4.5-kg (10-lb)

weight gain. She has not had her menstrual pe-

riod for the past 3 months. Physical examina-

tion is unremarkable except that a small

amount of white discharge is manually ex-

pressed from the nipples bilaterally. The serum

prolactin level is 300 ng/mL. Which of the fol-

lowing is the most appropriate first-line treatment?

(A) Bromocriptine

(B) Cortisol

(C) Methyldopa

(D) Metoclopramide

(E) Octreotide

Answer 32

32. The correct answer is A.

This patient is pre-

senting with signs and symptoms consistent

with hyperprolactinemia. The most likely

cause is a prolactin-secreting pituitary ade-

noma because the serum prolactin level is

>200 ng/mL. When the prolactin level is 20–

200 ng/mL, other causes of hyperprolactinemia

such as drugs, hypothyroidism, and renal fail-

ure should be considered. Bromocriptine is a

dopamine agonist that can decrease both pro-

lactin secretion and the size of the adenoma.

Question 33

33.

A 42-year-old woman with no significant past

medical history presents for a routine health

maintenance visit. On physical examination a

solitary nodule is palpated in the thyroid. She

denies pain, dysphagia, or hoarseness. She also

denies fatigue, weight change, heat or cold in-

tolerance, diarrhea, or constipation. There is

no family history of thyroid cancer. Her serum

thyroid-stimulating hormone level is normal.

Which of the following is the most appropriate

next step in evaluation?

(A) Fine-needle aspiration

(B) MRI

(C) Radionuclide scan

(D) Thyroid lobectomy

(E) Ultrasonography

Answer 33

33. The correct answer is A.

Palpable thyroid nod-

ules are more common in women, older pa-

tients, and people in iodine-defi cient parts of

the world. The initial step in evaluation should

be measuring the TSH level, which is usually

normal. However, in a “functional nodule”

that is producing excess hormone, it can be de-

creased. If the TSH is decreased, the next step

is a radionuclide scan to determine if the nod-

ule is “hot” (i.e., absorbs the radioactive iodide

readily). If it is “hot,” the risk of malignancy is

very low. If the TSH is normal, as in this case,

the next step is fi ne-needle aspiration of the

nodule. Those nodules found to be malignant

should be surgically removed. Radionuclide

scans can be helpful to identify “cold” nodules,

which should be removed surgically due to in-

creased risk of malignancy or simply to help lo-

calize the nodule prior to surgery.

Question 34

34.

A 60-year-old man presents to his primary care

physician for routine medical care. He has no

complaints, takes no medications, and has a

family history of DM. Examination is unre-

markable. A screening laboratory test reveals a

fasting blood glucose level of 152 mg/dL. One

week later the test is repeated and a value of

144 mg/dL is obtained. Which of the following

is the most likely cause of these findings?

(A) Autoimmune destruction of pancreatic islet cells

(B) Pancreatitis

(C) Patient’s findings represent normal labora-

tory values

(D) Peripheral insulin resistance

(E) Surreptitious insulin injection

Answer 34

34. The correct answer is D.

The finding on two

separate occasions of a fasting blood glucose

level of 126 mg/dL or higher indicates that the

patient has type 2 DM. The etiology of type 2

DM includes relative paucity of insulin secre-

tion, often in the presence of increased body

weight, peripheral insulin resistance, and im-

paired regulation of gluconeogenesis in the liver.

Question 35

35.

A 65-year-old man presents with a 1-day history

of hematuria and sharp fl ank pain (rated 10 of

10) radiating toward the groin on the right side.

Past medical history is signifi cant for three

prior episodes of nephrolithiasis over the past 5

years, all of which presented with a similar

clinical picture. He is not taking any medica-

tion. There is no family history of renal calculi,

renal disease, or endocrine disorders. His tem-

perature is 36.9°C (98.5°F), heart rate is 125/

min, and blood pressure is 132/86 mm Hg. He

is in obvious distress and cannot sit still on the

bed. Physical examination is signifi cant for a

soft, nontender abdomen and extreme costo-

vertebral angle tenderness on the right. Labo-

ratory values show:

Na+: 142 mEq/L

K+: 4.8 mEq/L

Cl−: 104 mEq/L

HCO3−: 24 mEq/L

Ca2+: 11.0 mg/dL

PO4: 1.4 mg/dL

Mg2+: 2.0 mg/dL

Blood urea nitrogen: 12 mg/dL

Creatinine: 1.0 mg/dL

Glucose: 118 mg/dL

Intact parathyroid hormone: 300 pg/mL

Which of the following is the most likely diagnosis?

(A) Malignancy

(B) Milk-alkali syndrome

(C) Primary hyperparathyroidism

(D) Sarcoidosis

(E) Secondary hyperparathyroidism

Answer 35

35. The correct answer is C.

This patient’s condi-

tion is consistent with primary hyperparathy-

roidism, most commonly due to a parathyroid

adenoma. Patients may present with recurrent

renal calculi, mental status changes, or abdom-

inal pain, but many asymptomatic patients are

diagnosed incidentally by fi ndings of elevated

serum calcium. Laboratory fi ndings include el-

evated intact PTH, hypercalcemia, and hypo-

phosphatemia. The elevated level of PTH

causes hypercalcemia via increased bone re-

sorption, increased distal tubular reabsorption

of calcium in the kidney, and stimulation of re-

nal hydroxylation of 25-hydroxyvitamin D,

which increases dietary calcium absorption in

the gastrointestinal tract. Elevated PTH causes

hypophosphatemia by inhibiting proximal tu-

bular reabsorption of phosphate in the kidney.

Question 36

36.

A 72-year-old woman presents to her physician

complaining of fatigue, malaise, weight loss,

and salt cravings. The patient has chronic ob-

structive pulmonary disease and is intermit-

tently treated with corticosteroids but is not us-

ing home oxygen. Her oxygen saturation is

97% on room air with a blood pressure of

115/65 mm Hg, which is significantly lower

than her baseline of 125/78 mm Hg. On aus-

cultation she has good breath sounds bilater-

ally without wheeze, although the expiratory

phase is slightly prolonged. Five weeks ago she

received a corticosteroid treatment for an acute

chronic obstructive pulmonary disease exacer-

bation, for which she was hospitalized and

given 3 L of oxygen via nasal cannula. How-

ever, she admits that after discharge she was

having continued diffi culty breathing and did

not follow the taper of the corticosteroids. The

patient has smoked one pack of cigarettes per

day for the past 51 years. Which of the follow-

ing is the appropriate fi rst step in the manage-

ment of this patient?

(A) 3 L of oxygen via nasal cannula

(B) CT scan of the chest

(C) Intravenous fluids

(D) Restart corticosteroids and follow a strict taper

(E) X-ray of the chest

Answer 36

36. The correct answer is D.

Patients who take

corticosteroids may develop secondary hypo-

adrenalism and may become unable to mount

an appropriate response to ACTH. This can re-

sult in renal failure, hypotension, and hypona-

tremia. Thus, restarting steroids is the first pri-

ority in this patient. Gradually tapering off of

steroids allows the suppressed adrenals time to

return to full function.

Question 37

37.

An obese patient with a long-standing history

of type 2 DM presents to his primary care phy-

sician. On examination he has decreased sen-

sation in both lower extremities. Upon ques-

tioning of his compliance with his prescribed

medications, he reports that he has stopped

taking one medication because it gave him

fl atulence and abdominal pain. Which of the

following did this man most likely stop taking?

(A) An α-glucosidase inhibitor

(B) Meglitinide

(C) Metformin

(D) Sulfonylurea

(E) Thiazolidinedione

Answer 37

37. The correct answer is A.

α-Glucosidase inhibi-

tors are medications that reduce the amount of

carbohydrates absorbed from the intestine.

They are not commonly used because of the

bothersome adverse effect of gastrointestinal

upset and flatulence.

Question 38

38.

A 19-year-old G1P0 woman at 32 weeks’ gesta-

tion presents for scheduled prenatal appoint-

ment. The pregnancy has been uncomplicated

to date. However, she mentions that she re-

cently noticed a hard lump on her neck. She

denies pain or difficulty swallowing, speaking,

or breathing. Physical examination reveals a

fi rm, nontender, immobile, solitary nodule on

the left hemithyroid. Ultrasound reveals a solid

2-cm mass. There is no cervical lymphadenop-

athy. Thyroid function tests reveal a thyroid-

stimulating hormone level of 1.2 μU/mL and

free thyroxine level of 0.9 ng/dL. Results of

fi ne-needle aspiration biopsy are shown in the

image. Which of the following is the best next

step in management?

A) Left hemithyroidectomy

(B) Monitor until after delivery

(C) Radioablation therapy

(D) Start methimazole

(E) Start propylthiouracil

Answer 38

38. The correct answer is B.

The image shows

well-differentiated papillary carcinoma. Papil-

lary carcinoma is the most common type of

thyroid cancer, and has an excellent prognosis.

A higher incidence is seen in women <20 or

>70 years old, as well as individuals with a his-

tory of head and neck radiation. Treatment is

surgical excision. However, in pregnant women

surgery is most safely performed during the

second trimester, and this patient is already

into her third trimester. The mass is small and

is not compressing surrounding structures to

cause dysphagia, dysphonia, or airway compro-

mise. The absence of cervical lymphadenopa-

thy suggests that the cancer has not metasta-

sized. Papillary carcinoma is generally slow

growing, and in the absence of metastasis may

be followed for the remaining weeks of the

pregnancy before treatment is initiated.

Question 39

39.

A 6-year-old boy presents to his pediatrician for

a routine physical examination. His mother re-

ports no problems over the past year except

that he seems to be shorter than the other boys

in his class. His mother is 163 cm (5’4”) tall

and experienced menarche at age 12 years,

and his father is 178 cm (5’10”) tall and went

through puberty at approximately age 14 years.

On his growth curve, the boy’s height was at

the 10th percentile at birth, at the sixth percen-

tile by age 3 years, and at the third percentile

now. His weight is currently at the 25th per-
centile. Which of the following is most impor-

tant in this patient’s evaluation?

(A) Chromosomal analysis

(B) Colonoscopy

(C) Growth hormone level

(D) Insulin-like growth factor-1 level

(E) No further evaluation is necessary

Answer 39

39. The correct answer is D.

The most concerning

type of short stature is attenuated growth, in

which the patient starts off at a normal height

but falls off of his growth curve as he gets older,

as this pattern is always pathologic and requires

further evaluation. Causes of attenuated growth

include renal disease, hypothyroidism, Crohn’s

disease, cancer, glucocorticoid therapy, and GH

deficiency. GH defi ciency is typically idiopathic,

but can also be caused by tumors, particularly

craniopharyngiomas, or rarely a genetic muta-

tion in the GH-releasing hormone receptor in

the pituitary. To diagnose GH deficiency, serum

IGF-1 levels should be measured as opposed to

GH levels, because GH is secreted in a pulsatile

fashion and a random measurement is not a re-

liable indicator of GH status, whereas IGF-1 is

produced by the liver under GH stimulation

and is a more reliable measurement of GH levels.

Question 40

40.

A 32-year-old man presents to his primary care

physician complaining of diffuse muscle weak-

ness, dry and puffy skin, and patchy areas of

hair loss on his scalp. He also notes numbness

around his mouth and a tingling sensation in

his hands and feet. He has a history of seizure

disorder, and has been taking carbamazepine

for the past 5 years. On physical examination

he has dry skin and coarse, brittle hair with

patchy alopecia. Tapping his right cheek causes

contraction of the muscles at the corner of his

mouth, nose, and eye on the right side. Which

of the following could best have prevented the

development of the patient’s current problem?

(A) Magnesium supplementation

(B) Parathyroidectomy

(C) Thyroid hormone

(D) Vitamin C supplementation

(E) Vitamin D supplementation

Answer 40

40. The correct answer is E.

This man has signs

and symptoms that indicate hypocalcemia. His

complaints of weakness, dry skin, alopecia, cir-

cumoral numbness, and paresthesias are all

consistent with hypocalcemia. These patients

can also develop cataracts, myocardial dysfunc-

tion, osteomalacia, and seizures. This patient

has a positive Chvostek’s sign, which is ipsilat-

eral contraction of the facial muscles following

tapping the facial nerve. The most likely cause

of this patient’s hypocalcemia is vitamin D de-

fi ciency due to therapy with carbamazepine.

Carbamazepine and other medications includ-

ing phenytoin, rifampin, and theophylline in-

crease the activity of cytochrome P450 en-

zymes in the liver that inactivate vitamin D.

Deficient vitamin D leads to decreased absorp-

tion of calcium from the gut.

Question 41

41.

A 16-year-old obese Hispanic girl presents to

her physician’s offi ce complaining of “ugly skin

around my neck” and having to wear turtle-

necks. On examination the physician notes

darkening and thickening of the skin, which

has a velvety appearance. Which of the follow-

ing is the most appropriate course of action?

(A) Obtain a CT scan of the abdomen

(B) Obtain a punch biopsy of the affected skin

(C) Obtain a serum glucose test

(D) Obtain a shave biopsy of the affected skin

(E) Obtain liver function tests

Answer 41

41. The correct answer is C.

Acanthosis nigricans

is a velvety dark thickening of the skin around

the neck, axillae, and groin areas. It is related

to DM, malignancy, obesity, drugs, and various

endocrine disorders, and is not uncommonly

found in young Hispanic women. DM should

be suspected in this case, as well as in other

conditions associated with insulin resistance

such as polycystic ovarian syndrome.

Question 42

42.

A 24-year-old woman comes into the emer-

gency department with recurrent episodes of

palpitations, headache, and tremor. Her blood

pressure is 155/95 mm Hg, heart rate is 135/

min, temperature is 37.9°C (100.2°F), and re-

spiratory rate is 12/min. A CT of the abdomen

shows a suprarenal mass. After confirming the

diagnosis with a laboratory test, the physician

informs the patient that she will require imme-

diate therapy and surgical resection of the mass

within the next few weeks. In order to achieve

short-term control of her blood pressure, which

of the following agents is most appropriate?

(A) Furosemide

(B) Hydralazine

(C) Phenelzine

(D) Prazosin

(E) Propanolol

Answer 42

42. The correct answer is D.

The symptoms of

headache, palpitations, and tremor are all con-

sistent with a pheochromocytoma, as is the CT

finding of a suprarenal mass. The confirming

laboratory test was likely an elevated urinary

catecholamine level; also, serum calcium and

glucose may well have been high. A pheochro-

mocytoma secretes excessive amounts of epi-

nephrine and norepinephrine, resulting in

both peripheral vasoconstriction (α-mediated

effect) and increased cardiac contractility

(β-mediated effect). An α-adrenergic blocker

such as prazosin is the principal means of re-

lieving hypertension in these patients.

Question 43

43.

A 49-year-old man presents to the clinic for a

health maintenance visit. He has a family his-

tory of type 2 DM. His medical history is signifi

cant for gastroesophageal refl ux disease, for

which he takes omeprazole and over-the-coun-

ter antacids. He smokes one pack of cigarettes

per day and drinks an average of two beers per

night. The patient’s body mass index is 32 kg/

m². Which of the following most greatly

reduce(s) the patient’s risk of future coronary

artery disease, renal failure, and retinopathy?

(A) Alcohol avoidance

(B) Daily multivitamin

(C) Diet rich in fruit and vegetables

(D) Smoking cessation

(E) Weight loss and exercise

Answer 43

43. The correct answer is E.

Reduction in weight

by just 7% and incorporating 30 minutes of

daily activity reduced risk of DM by 58% in a

landmark study. According to the AMerican

Heart Association, diabetes is an independent

risk factor for coronary artery disease. There-

fore, lowering the risk of diabetes will, in turn,

decrease the risk of coronary artery disease.

Question 44

44.

A 72-year-old man with end-stage renal disease

secondary to hypertension presents with several

months of back pain. He denies fever, weight

loss, diffi culty walking, altered sensation in his

legs, or incontinence. He was diagnosed with

renal disease 20 years ago and was managed

medically for many years. However, 2 years ago

he began hemodialysis because of a progressive

decline in renal function. There is no family

history of renal disease or malignancy. Physical

examination is unremarkable. X-ray of the

chest shows ill-defi ned bands of increased bone

density adjacent to the vertebral endplates.

What laboratory abnormalities is most likely in

this patient?

(A) Bence-Jones protein in urine

(B) Decreased parathyroid hormone

(C) Decreased phosphate

(D) Elevated bone-specific alkaline phosphatase

(E) Elevated parathyroid hormone

Answer 44

44. The correct answer is E.

This patient has radio-

graphic findings consistent with bone disease

caused by secondary hyperparathyroidism. Pa-

tients with end-stage renal disease have impaired

excretion of phosphate. Excess phosphate com-

plexes with calcium, leading to a secondary in-

crease in PTH secretion. PTH acts on the bone

to increase osteoclastic resorption in an attempt

to normalize serum calcium. Over time this can

lead to the pathologic condition osteitis fibrosa

cystica. Patients develop subperiosteal bone re-

sorption, which classically affects the clavicle,

phalanges, and vertebral bodies. X-ray of the

chest may show a classic “rugby jersey” (striped

like a rugby jersey) spine due to ill-defined

bands of increased bone density adjacent to the

vertebral endplates.

Question 45

45.

A 32-year-old G2P1 woman at 16 weeks’ ges-

tation presents to her obstetrician complain-

ing of fatigue, anxiety, and palpitations. She

says she has been feeling warm, even in her

air-conditioned home, and has been having

three or four loose stools per day, as compared

to one or two prior to her pregnancy. She has

a temperature of 37.1°C (98.9°F), heart rate

of 105/min, and blood pressure of 128/76 mm

Hg. Neck examination reveals mild diffuse

enlargement of the thyroid gland with no

lymphadenopathy.

Relevant laboratory find-

ings include a total triiodothyronine level of

400 ng/dL, free thyroxine of 6.8 ng/dL, and

thyroid-stimulating hormone of 0.01 μU/mL

(normal: 0.4–4 μU/L). Results of a thyroid-

stimulating hormone- receptor antibody test are

positive. Which of the following is the most ap-

propriate therapy for this patient?

(A) High-dose iodine therapy

(B) Methimazole

(C) Propylthiouracil

(D) Radioiodine ablation

(E) Surgical resection

Answer 45

45. The correct answer is C.

This patient has clini-

cal symptoms and laboratory evidence consis-

tent with hyperthyroidism and the presence of

TSH-receptor antibodies is consistent with

Graves’ disease, which is the most common

cause of hyperthyroidism in both normal pa-

tients and pregnant women. If left untreated,

maternal hyperthyroidism can lead to spontane-

ous abortion, premature labor, preeclampsia,

and maternal heart failure. The thionamides are

considered fi rst-line therapy in pregnant

women, including methimazole and propylthio-

uracil. Although both cross the placenta and

can cause fetal goiter and hypothyroidism, pro-

pylthiouracil is the preferred drug because it has

a lower risk of severe congenital anomalies.

Question 46

46.

A 32-year-old woman undergoes a cesarean

section because of failure of labor to progress,

and delivers a healthy baby boy. The proce-

dure is complicated by significant intraopera-

tive blood loss and hypotension, but the patient

is successfully resuscitated. Postoperatively she

experiences dull, aching, non-localized ab-

dominal pain and nausea, but denies head-

ache, visual changes, or abnormal edema. On

postoperative day three she is passing flatus and

remains afebrile, but becomes hypotensive to

90–100 mm Hg systolic and 40–50 mm Hg di-

astolic. She has not begun lactating despite her

attempts to breast-feed her infant. Laboratory

values indicate that she is hyponatremic and

mildly hyperkalemic. Urinalysis and liver en-

zymes are normal. Which of the following is

the most likely cause of her symptoms?

(A) Appendicitis

(B) HELLP syndrome

(C) Postoperative infection

(D) Sheehan’s syndrome

(E) Toxic shock syndrome

Answer 46

46. The correct answer is D.

Sheehan’s syndrome

is postpartum pituitary necrosis, usually in the

setting of obstetric hemorrhage and circulatory

collapse. Sheehan’s syndrome is a secondary

cause of hypoadrenalism, which would explain

the patient’s hyponatremia. Also common are

abdominal pain, weakness, fatigue, and hy-

potension. The patient with Sheehan’s syn-

drome will often have an inability to breast-feed

secondary to defi cient prolactin production and

have other endocrine abnormalities associated

with loss of anterior pituitary hormone produc-

tion (the posterior pituitary is usually preserved),

such as hypothyroidism.

Question 47

47.

A 52-year-old man presents to the primary care

clinic for the fi rst time. He states that he has

been in good health throughout his life and

takes no medications. He was once athletic but

has noted a dramatic decrease in his muscle

strength and exercise tolerance over the past

year. On examination the patient is moderately

hypertensive, with a tanned, round, plethoric

face; large supraclavicular fat pads; and signifi

cant truncal obesity. He has no focal cardiovas-

cular, pulmonary, or neurologic findings. His

fasting blood sugar is 200 mg/dL. Which of the

following is the most common etiology of this

condition?

(A) ACTH-secreting pituitary adenoma

(B) Adrenal tumor

(C) Ectopic ACTH-secreting tumor

(D) Primary adrenal hyperplasia

(E) Small cell lung cancer

Answer 47

47. The correct answer is A.

This patient has the

classic symptoms of Cushing’s syndrome,

which most directly results from an excess of

cortisol. ACTH is secreted by the anterior pitu-

itary and stimulates the adrenal cortex to se-

crete cortisol. The most common cause of

Cushing’s syndrome is exogenously adminis-

tered corticosteroids; however, the patient was

not on any medication, and the most common

noniatrogenic etiology is Cushing’s disease, an

ACTH-secreting pituitary adenoma. In addi-

tion, hyperpigmentation with hypercortisolism

is only seen in Cushing’s disease, due to in-

creased production of melanocyte-stimulating

hormone induced by the tumor.

Question 48

48.

A 48-year-old high school teacher with no prior

medical history presents to his primary care

physician after feeling extremely fatigued for

>1 month. Previously an avid runner, he has

recently experienced dyspnea on moderate ex-

ertion. Although he denies vomiting, he admits

to intermittent episodes of diarrhea. His blood

pressure is 73/37 mm Hg and he is afebrile.

On physical examination his skin is warm and

erythematous, and his jugular venous pressure

is elevated. Cardiac examination reveals a sys-

tolic murmur near the right border of the ster-

num that is accentuated with inspiration.

Which of the following is most consistent with these findings?

(A) Elevated urinary excretion of 5-hydroxyindoleacetic acid

(B) Elevated urinary excretion of vanillylmandelic acid

(C) Peaked T waves on ECG

(D) Pseudomonas species grown from blood cultures

(E) Severe pulmonary congestion on x-ray of the chest

Answer 48

48. The correct answer is A.

Increased levels of

urine 5-hydroxyindoleacetic acid (5-HIAA) are

a byproduct of serotonin metabolism and are

consistent with carcinoid syndrome. Carcinoid

tumors often affect the right heart due to fi

brous deposits on the right-sided valves that

can induce right-sided heart failure. The carci-

noid syndrome includes fl ushing, diarrhea, and

hypotension. The murmur is likely due to tri-

cuspid regurgitation, although pulmonary

valve involvement is also common. Patients

with cardiac involvement have higher levels of

plasma serotonin and urine 5-HIAA.

Question 49

49.

A 3-year-old girl is brought to the pediatrician’s

office because of an abdominal mass. Physical

examination reveals short stature, coarse facial

features, a protruding tongue, and an easily re-

ducible umbilical hernia. The girl has diffi

culty walking and knows six words, although

she is unable to form a sentence. Her mother

reports no health problems and an uncompli-

cated pregnancy. What is the most likely cause

of the patient’s condition?

(A) Congenital hypothyroidism

(B) Cushing’s syndrome

(C) Neuroblastoma

(D) Phenylketonuria

(E) Turner’s syndrome

Answer 49

49. The correct answer is A.

The patient has con-

genital hypothyroidism, which usually results

from thyroid gland dysgenesis. It may also occur

from inborn errors in thyroid hormone metabo-

lism or from the presence of TSH receptor anti-

bodies. Infants with congenital hypothyroidism

often appear normal at birth, although some de-

velop jaundice and hypotonia. Children with

hypothyroidism may also present with protrud-

ing tongue and abdomen, umbilical hernias,

and failure to thrive. Permanent neurologic

damage results if treatment is delayed. The

child in this case exhibits the physical features

of congenital hypothyroidism. She also exhibits

profound motor and cognitive developmental

delay. Her neurologic defi cits are most likely ir-

reversible at this stage, but treatment with exog-

enous thyroid hormone should be initiated to

prevent other sequelae of hypothyroidism, such

as myxedema coma. Neurologic abnormalities

could have been prevented with neonatal

screening, which evaluates TSH or levothyrox-

ine levels. Early intervention with exogenous

levothyroxine and close TSH level monitoring

can result in normal IQ.

Question 50

50.

A 3010-g (6.6-lb) boy was born to a 37-year-old

primagravida by spontaneous vaginal delivery

after an uncomplicated pregnancy. On exami-

nation he has cyanotic extremities and a signif-

icant right precordial heave, a single S2, and a

harsh systolic ejection murmur along the ster-

nal border. He also has a prominent squared

nose and cleft palate. An echocardiogram is

subsequently performed and demonstrates te-

tralogy of Fallot. Corrective surgery is per-

formed without complications. At 2 months of

age the infant is diagnosed with

Pneumocystis jiroveci pneumonia, and at 3 months he

is diagnosed with fungal septicemia. Additional work-

up of this child should include which of the following tests?

(A) Hemoglobin electrophoresis

(B) Nitroblue tetrazolium

(C) Quantitative immunoglobulin levels

(D) Renal ultrasound

(E) Serum calcium

Answer 50

50. The correct answer is E.

This child has Di-

George’s syndrome, with deletion of chromo-

some 22q11. This chromosomal anomaly

causes the third and fourth pharyngeal pouches

to develop abnormally, resulting in midline de-

fects. Abnormal facies, cleft palate, congenital

heart defects, thymic aplasia, and parathyroid

hypoplasia with hypocalcemia characterize Di-

George’s syndrome. Patients are identified by

physical examination, tetany in the neonatal

period, and frequent infections, especially with

fungus and/or P. jiroveci. Evaluation should

include measurement of serum calcium,

echocardiogram, and absolute lymphocyte

count. The diagnosis is made by detection of

the deletion on fluorescent in situ hybridization.