USMLE Step 1 Medical Subject Review: Pathology
CNS
12-year-old boy is prepubescent and has grown to over two meters tall. An MRI of his
head reveals an extrasellar mass. The boy's tall stature is MOST probably due to which
of the following physiologic processes? - ANSW pituitary adenoma secreting elevated
growth hormone
55-year-old man has had emotional changes consisting of sexual disinhibition and
emotional apathy. He later has difficulty with expressing himself and doing his usual
routine. The magnetic resonance imaging (MRI) reveals atrophy of the frontal and
temporal lobes, along with swollen neurons in the temporal and frontal areas of the
brain, and intraneuronal argentophilic inclusion bodies in these same areas. What type
of dementia is this patient exhibiting? - ANSW Dementia due to Pick's disease
69-year-old woman suffered a massive stroke 6 weeks ago. She is now recovering from
the stroke, but she has residual paralysis and sensory impairment of her right arm. She
is also unable to speak and unable to turn her eyes to the right. The most likely site of
her lesion is in the area that is supplied by what artery? - ANSW Left middle cerebral
artery
65-year-old woman has a long-standing dementing disorder characterized by
deterioration in personality, neglect of personal hygiene, impaired judgment, and
uninhibited behavior. MRI demonstrates severe cortical atrophy limited to the frontal
lobes and anterior two thirds of the temporal lobes, while the remaining cortex is
preserved. No evidence of recent or remote infarcts is found. What diagnosis is most
consistent with these pathologic and clinical features? - ANSW Frontotemporal
dementia
53-year-old man presents with a 2-week history of severe headaches that occur
primarily at night. The patient is pacing while he is talking. The pain surrounds one eye
and lasts for 30-90 minutes. He also states that there is ipsilateral lacrimation,
conjunctival injection, and nasal congestion during the attacks. The patient states that
he has had these headaches once a day over the last week. He cannot point to any one
thing that causes them. On examination, the patient has features of partial Horner's
syndrome. His vital signs are temperature: 97.0°F, heart rate: 80/min, respiration
16/min, and blood pressure: 126/80 mm Hg. What is the most likely diagnosis? - ANSW
Cluster headache
3-year-old girl shows a white reflection from the surface of the retina upon
ophthalmologic examination. Biopsy of the lesion reveals retinoblastoma (Rb).
Underphosphorylated Rb gene product has which significant characteristic? - ANSW
prevents mitosis
,38-year-old man with uncontrolled facial movements states that he has noticed himself
over the last few months making expressions without even realizing it or being able to
control it. Further questioning reveals that he also has noted an inability to intentionally
move his eyes quickly without blinking. Very recently, he noted an inability to sustain
physical movements, such as grasping objects with his hands. Physical examination
reveals a puppet-like gait and obvious chorea. The patient admits that he does not know
anything about his family history due to the fact that he was adopted when he was 4.
Based on the history and physical examination findings, what is the most likely
diagnosis? - ANSW Huntington's disease
54-year-old white male presents with gradual onset of mild dementia, ataxic gait, and
startle myoclonus. An MRI scan is normal, and an examination of his cerebrospinal fluid
reveals no abnormalities, but the patient's EEG is remarkable for recurrent bursts of
high-voltage slow waves. Over the next 6 months, the patient's dementia rapidly
worsens, accompanied by general hypertonicity and profound dysarthria. The patient
dies shortly thereafter. What is the most likely neuropathological finding on autopsy? -
ANSW Diffuse spongiform change
35-year-old woman presents with proptosis and diminishing vision in her right eye.
Magnetic resonance imaging demonstrated a well-demarcated, globular mass arising
from the optic nerve. Microscopic examination of the enucleated mass shows cells with
nuclei having finely dispersed chromatin and inconspicuous nucleus. The cells have
poorly defined borders forming whorls around vessels and stromal elements. What is
the most likely diagnosis? - ANSW Meningioma
35-year-old woman with Down syndrome (trisomy 21) is brought in by her family.
Previously, she had learned to read street signs and write her name. Until a year ago,
she attended a sheltered workshop where she sorted color coded components for
appliance repair. In the past year, she has become more impaired and can no longer
reliably recognize people she does not see every day. She is no longer able to dress
herself, and she is unable to work. On mental status examination, she is pleasant but
distracted, and she is oriented to person only. Her speech is grammatically fragmented
and dysarthric. She cannot remember what she ate for lunch an hour before. She does
not recognize a picture of a stop sign. What is the most likely diagnosis? - ANSW
Dementia of the Alzheimer type
72-year-old man exhibits progressive tremors, bradykinesia, and muscular rigidity. He is
slow to initiate movements and shows other motor abnormalities. The most likely
diagnosis of his disease is which of the following conditions? - ANSW Parkinson
disease
A CT-scan of a patient reveals damage to the medulla oblongata in the region supplied
by the posterior inferior cerebellar artery. The neurologist concludes that the patient has
a classic Wallenberg (lateral medullary) syndrome. The patient would show dysphagia
, and dysarthria due to which of the following? - ANSW destruction of the nucleus
ambiguus
64-year-old man with a medical history of hypertension and diabetes mellitus presents
because his wife is concerned that he is losing his memory. She states it might have all
started when he had a stroke 1 year ago. He began to have difficulty remembering
where his glasses are and difficulty going to the store to pick up groceries. The patient
had seemingly improved, but a few months later he began to have increased difficulty
following instructions, mood swings, and problems handling money. The patient does
not report aphasia, incontinence, problems with gait, or weakness. Vital signs are T
99.2°F, BP 140/94mm Hg, P 98/min, and R 14/min. TSH, B12, serum electrolytes, and
fasting glucose are within normal limits. What is the most likely pathogenesis of this
patient's disease? - ANSW Multiple small cerebral infarctions
35-year-old, sexually active woman misses her period. She takes a home pregnancy
test, but it is negative. She does not worry about it and attributes it to stress. She has
been under a lot of pressure at work lately and has had headaches that she also
attributes to stress. However, she misses her next period and the one after that as well.
She notices that she has milk discharge from her breasts and becomes quite concerned
that she might be pregnant. She buys another home pregnancy test, and again the test
is negative. She sees her OB-GYN. On questioning during the medical history, she
comments that up until a few months ago her periods had been every 28 days. Several
blood tests are done. Her results are in the chart.
TEST
RESULTS
REFERENCE RANGE
Urine beta hCG
Negative
Negative
Serum beta hCG
Negative
Negative
Prolactin
312 ng/mL
<20 ng/mL
Serum LH
2 mIU/mL
3-30 mIU/mL
Serum FSH
3 mIU/mL
4-90 mIU/mL
On physical exa - ANSW Bitemporal hemianopsia
40-year-old man presents to the psychiatrist due to forgetting things more and more
frequently, a lack of energy, and the feeling that someone trying to kill him. He says that
his father has a neurological disease, but he cannot remember the name. At the
CNS
12-year-old boy is prepubescent and has grown to over two meters tall. An MRI of his
head reveals an extrasellar mass. The boy's tall stature is MOST probably due to which
of the following physiologic processes? - ANSW pituitary adenoma secreting elevated
growth hormone
55-year-old man has had emotional changes consisting of sexual disinhibition and
emotional apathy. He later has difficulty with expressing himself and doing his usual
routine. The magnetic resonance imaging (MRI) reveals atrophy of the frontal and
temporal lobes, along with swollen neurons in the temporal and frontal areas of the
brain, and intraneuronal argentophilic inclusion bodies in these same areas. What type
of dementia is this patient exhibiting? - ANSW Dementia due to Pick's disease
69-year-old woman suffered a massive stroke 6 weeks ago. She is now recovering from
the stroke, but she has residual paralysis and sensory impairment of her right arm. She
is also unable to speak and unable to turn her eyes to the right. The most likely site of
her lesion is in the area that is supplied by what artery? - ANSW Left middle cerebral
artery
65-year-old woman has a long-standing dementing disorder characterized by
deterioration in personality, neglect of personal hygiene, impaired judgment, and
uninhibited behavior. MRI demonstrates severe cortical atrophy limited to the frontal
lobes and anterior two thirds of the temporal lobes, while the remaining cortex is
preserved. No evidence of recent or remote infarcts is found. What diagnosis is most
consistent with these pathologic and clinical features? - ANSW Frontotemporal
dementia
53-year-old man presents with a 2-week history of severe headaches that occur
primarily at night. The patient is pacing while he is talking. The pain surrounds one eye
and lasts for 30-90 minutes. He also states that there is ipsilateral lacrimation,
conjunctival injection, and nasal congestion during the attacks. The patient states that
he has had these headaches once a day over the last week. He cannot point to any one
thing that causes them. On examination, the patient has features of partial Horner's
syndrome. His vital signs are temperature: 97.0°F, heart rate: 80/min, respiration
16/min, and blood pressure: 126/80 mm Hg. What is the most likely diagnosis? - ANSW
Cluster headache
3-year-old girl shows a white reflection from the surface of the retina upon
ophthalmologic examination. Biopsy of the lesion reveals retinoblastoma (Rb).
Underphosphorylated Rb gene product has which significant characteristic? - ANSW
prevents mitosis
,38-year-old man with uncontrolled facial movements states that he has noticed himself
over the last few months making expressions without even realizing it or being able to
control it. Further questioning reveals that he also has noted an inability to intentionally
move his eyes quickly without blinking. Very recently, he noted an inability to sustain
physical movements, such as grasping objects with his hands. Physical examination
reveals a puppet-like gait and obvious chorea. The patient admits that he does not know
anything about his family history due to the fact that he was adopted when he was 4.
Based on the history and physical examination findings, what is the most likely
diagnosis? - ANSW Huntington's disease
54-year-old white male presents with gradual onset of mild dementia, ataxic gait, and
startle myoclonus. An MRI scan is normal, and an examination of his cerebrospinal fluid
reveals no abnormalities, but the patient's EEG is remarkable for recurrent bursts of
high-voltage slow waves. Over the next 6 months, the patient's dementia rapidly
worsens, accompanied by general hypertonicity and profound dysarthria. The patient
dies shortly thereafter. What is the most likely neuropathological finding on autopsy? -
ANSW Diffuse spongiform change
35-year-old woman presents with proptosis and diminishing vision in her right eye.
Magnetic resonance imaging demonstrated a well-demarcated, globular mass arising
from the optic nerve. Microscopic examination of the enucleated mass shows cells with
nuclei having finely dispersed chromatin and inconspicuous nucleus. The cells have
poorly defined borders forming whorls around vessels and stromal elements. What is
the most likely diagnosis? - ANSW Meningioma
35-year-old woman with Down syndrome (trisomy 21) is brought in by her family.
Previously, she had learned to read street signs and write her name. Until a year ago,
she attended a sheltered workshop where she sorted color coded components for
appliance repair. In the past year, she has become more impaired and can no longer
reliably recognize people she does not see every day. She is no longer able to dress
herself, and she is unable to work. On mental status examination, she is pleasant but
distracted, and she is oriented to person only. Her speech is grammatically fragmented
and dysarthric. She cannot remember what she ate for lunch an hour before. She does
not recognize a picture of a stop sign. What is the most likely diagnosis? - ANSW
Dementia of the Alzheimer type
72-year-old man exhibits progressive tremors, bradykinesia, and muscular rigidity. He is
slow to initiate movements and shows other motor abnormalities. The most likely
diagnosis of his disease is which of the following conditions? - ANSW Parkinson
disease
A CT-scan of a patient reveals damage to the medulla oblongata in the region supplied
by the posterior inferior cerebellar artery. The neurologist concludes that the patient has
a classic Wallenberg (lateral medullary) syndrome. The patient would show dysphagia
, and dysarthria due to which of the following? - ANSW destruction of the nucleus
ambiguus
64-year-old man with a medical history of hypertension and diabetes mellitus presents
because his wife is concerned that he is losing his memory. She states it might have all
started when he had a stroke 1 year ago. He began to have difficulty remembering
where his glasses are and difficulty going to the store to pick up groceries. The patient
had seemingly improved, but a few months later he began to have increased difficulty
following instructions, mood swings, and problems handling money. The patient does
not report aphasia, incontinence, problems with gait, or weakness. Vital signs are T
99.2°F, BP 140/94mm Hg, P 98/min, and R 14/min. TSH, B12, serum electrolytes, and
fasting glucose are within normal limits. What is the most likely pathogenesis of this
patient's disease? - ANSW Multiple small cerebral infarctions
35-year-old, sexually active woman misses her period. She takes a home pregnancy
test, but it is negative. She does not worry about it and attributes it to stress. She has
been under a lot of pressure at work lately and has had headaches that she also
attributes to stress. However, she misses her next period and the one after that as well.
She notices that she has milk discharge from her breasts and becomes quite concerned
that she might be pregnant. She buys another home pregnancy test, and again the test
is negative. She sees her OB-GYN. On questioning during the medical history, she
comments that up until a few months ago her periods had been every 28 days. Several
blood tests are done. Her results are in the chart.
TEST
RESULTS
REFERENCE RANGE
Urine beta hCG
Negative
Negative
Serum beta hCG
Negative
Negative
Prolactin
312 ng/mL
<20 ng/mL
Serum LH
2 mIU/mL
3-30 mIU/mL
Serum FSH
3 mIU/mL
4-90 mIU/mL
On physical exa - ANSW Bitemporal hemianopsia
40-year-old man presents to the psychiatrist due to forgetting things more and more
frequently, a lack of energy, and the feeling that someone trying to kill him. He says that
his father has a neurological disease, but he cannot remember the name. At the
