Endocrinology Flashcards
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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).
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
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
- 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.
