NBME Sample Questions and Answers
2023
A 67-year-old woman is hospitalized because of abdominal pain and persistent copious
vomiting for 24 hours. Two weeks ago, she was hospitalized for treatment of atrial
fibrillation; after cardioversion to a normal sinus rhythm, she began treatment with
warfarin. Yesterday, at a follow-up visit, her INR was 6 (?? normal), and her medication
was discontinued. She takes no other medications. Her temperature is 37°C (98.6°F),
pulse is 120/min and regular, respirations are 20/min, and blood pressure is 100/78 mm
Hg. The abdomen is distended and moderately tender; there is voluntary guarding in the
epigastrium (??? source of pain) There are no masses, organomegaly, or obvious
hernias. Rectal examination shows no abnormalities. Test of the stool for occult blood is
negative. Her hemoglobin concentration has decreased from 13 g/dL yesterday to 7.8
g/dL today. An ECG shows a normal sinus rhythm. Which of the following is the most
likely explanation for this patient's abdominal symptoms? - Correct Answer Intramural
hematoma of the proximal small bowel
A 4-year-old boy is brought to the physician by his parents because of fatigue and
irritability over the past 2 months. The family visited relatives in rural Louisiana 5 months
ago where the patient ran around barefoot. The child is active and appears normal. The
conjunctivae are pale. Laboratory studies include a normal leukocyte count with 15%
eosinophils. A stool preparation discloses the parasite egg shown. Which of the
following is the most likely cause of fatigue and irritability in this patient? - Correct
Answer Microcytic anemia
Two days after beginning primaquine for malaria prophylaxis, a 17-year-old African
American boy is brought to the physician because of dark urine and yellowing of his
eyes. His pulse is 88/min, respirations are 12/min, and blood pressure is 124/68 mm
Hg. Examination shows scleral icterus and pale mucous membranes. His hemoglobin
concentration is 10 g/dL. A blood smear shows erythrocyte fragments and Heinz bodies.
Which of the following is the most likely explanation for these findings? - Correct
Answer Deficiency of glucose 6-phosphate dehydrogenase
A one-day-old newborn male is found to have hemolytic disease of the newborn. Both
parents are Rh-positive, mother is positive for IgG isohemagglutinins, while father is
negative. Which of the following parental blood types most likely caused this condition?
- Correct Answer Mother: O and Father: AB
One week after receiving 4 units of packed red blood cells for acute hemorrhage due to
a gunshot wound, a 17-year-old male develops fatigue, jaundice. Laboratory results
show the following:Hemoglobin 8.8 g/dL Hematocrit 28%, Serum total bilirubin 5 mg/dL
Serum lactate dehydrogenase 120 U/L. Liver and kidney function tests are otherwise
within normal limits. Which of the following is the most appropriate next step in
diagnosis? - Correct Answer Direct and indirect antiglobulin (Coombs) tests
,A 6-month-old boy is brought to the physician because of left knee swelling for 24
hours. Three months ago, he had three large hematomas on his forehead that resolved
without treatment (??). His two sisters and his mother have no history of similar
symptoms. His mother's maternal uncle and her brother died (x-linked recessive) before
the age of 30 years of massive cerebral hemorrhages. Physical examination shows
deep ecchymosis over the buttocks and severe swelling of the left knee. The most likely
explanation for these findings is a deficiency of which of the following? - Correct
Answer Factor VIII (antihemophilic factor)
Three days after undergoing elective laparoscopic cholecystectomy for cholelithiasis, a
42-year-old woman has the onset of hematomas at all surgical sites. She was treated
for deep venous thrombosis 3 years ago but was not taking any medications at the time
of this admission. Results of preoperative laboratory studies were within the reference
range. Prior to the operation, she received heparin and underwent application of
compression stockings. Her initial postoperative course was uncomplicated. Heronly
medication is ibuprofen. She is 163 cm (5 ft 4 in) tall and weighs 87 kg (192 lb); BMI is
33 kg/m2. Her temperature is 37.3°C(99.2°F), pulse is 94/min, respirations are 16/min,
and blood pressure is 112/74 mm Hg. Examination shows mild hematomas at all
surgical sites. The abdomen is soft and nontender. There is no organomegaly. Bowel
sounds are normal. Laboratory studies show:Hemoglobin 10.3 g/dL Hematocrit
30%Leukocyte count 12,000/mm3 Platelet count 45,000/mm3 Which of the following is
the most likely cause of this patient's current findings? - Correct Answer Heparin-
induced thrombocytopenia
A 3-year-old girl with Down syndrome is brought to the physician because of a 1-week
history of frequent nosebleeds, decreased appetite, and lethargy. She takes no
medications. Her temperature is 38°C (100.4°F), pulse is 100/min, respirations are
20/min,and blood pressure is 80/45 mm Hg. Examination shows no other abnormalities
except for pallor. Laboratory studies show:Hemoglobin 6.5 g/dL Hematocrit
19%Leukocyte count 100,000/mm3 Segmented neutrophils 15%Atypical lymphocytes
85%Platelet count 45,000/mm3 Which of the following is the most likely mechanism of
these laboratory findings? - Correct Answer Infiltration of bone marrow by leukemic
blasts
A 30-year-old woman, gravida 2, para 1, comes for her first prenatal visit at 26 weeks'
gestation. Uterine size is greater than expected for dates. Ultrasonography shows fetal
hydrops. Which of the following is the most appropriate next step in diagnosis? -
Correct Answer Maternal Rh status with antibody screening
A 65-year-old man has had increasingly severe headaches and diffuse muscle aches
during the past 3 months. He also has a 1-month history of jaw pain when chewing food
and decreasing visual acuity in his left eye. His temperature is 38°C (100.4°F). Visual
acuity in his left eye is 20/100, and the left optic disc is slightly atrophic. His muscle
strength is normal. Which of the following tests should be obtained next? - Correct
Answer Measurement of erythrocyte sedimentation rate
,A 10-year-old boy has had anemia since birth. His spleen is five times normal size.
Splenectomy is indicated if the anemia is caused by which of the following disorders? -
Correct Answer Hereditary spherocytosis
A previously healthy 72-year-old man is brought to the physician because of weakness
and fatigue. His hemoglobin concentration is 9.2 g/dl, leukocyte count is 5400/mm3, and
platelet count is 350,000/mm3. A peripheral blood smear is shown. Which of the
following is the most likely cause of these findings? - Correct Answer Gastrointestinal
blood loss
A 48-year-old man comes to the physician because of increasing bronzing of his skin,
weakness, and fatigue during the past 3 months. Physical examination shows bronzing
of the skin, hepatomegaly, and small testes. Serum studies show: Which of the
following best explains the findings in this patient? - Correct Answer Increased
intestinal iron absorption
A 3-year-old boy and his 5-year-old brother bruise easily and have recurrent
hemarthrosis. Both parents are healthy, but the mother has two younger brothers with
the same symptoms and a maternal uncle who died at 8 years of age after mild head
trauma. Partial thromboplastin time is prolonged. The most likely defect involves which
of the following? - Correct Answer Factor VIII (antihemophilic factor)
An 81-year-old woman is admitted to the hospital because of a massive pulmonary
embolism from a deep venous thrombosis. Her platelet count is 160,000/mm3.
Appropriate pharmacotherapy is started. One week later, her platelet count is
55,000/mm3. The thrombocytopenia was most likely caused by a drug with which of the
following mechanisms of action? - Correct Answer Potentiates the action of
antithrombin III
A 62-year-old woman with recurrent pulmonary emboli comes to the physician for a
follow-up examination. Physical examination shows no abnormalities. Laboratory
studies show a prothrombin time of 12 seconds. Warfarin therapy is begun. Which of
the following clotting factors is the first to be decreased by 50% after the initiation of
therapy? - Correct Answer VII (proconvertin)
A 40-year-old man is evaluated because his skin is extremely sensitive to sunlight.
Exposure to the sun causes the formation of vesicles and blisters on the skin, which
frequently take weeks to heal. He is diagnosed with a disorder caused by the increased
synthesis of compounds in the skin that are subject to excitation by visible light. Which
of the following biochemical pathways is most likely defective in this patient? - Correct
Answer Heme synthesis
A 53-year-old man, who recently returned from Africa, has fever, headache, and
abdominal discomfort. He received appropriate vaccinations prior to the trip. His
temperature is 39.4°C (103°F). Physical examination shows no other abnormalities. A
, Wright-stained peripheral blood smear is shown. Which of the following is the most
likely diagnosis? - Correct Answer Malaria
A 10-year-old boy is brought to the physician because of a 4-day history of nosebleeds
and easy bruising. Three weeks ago, he had an upper respiratory tract infection.
Physical examination shows ecchymoses over the upper and lower extremities.
Laboratory studies show a hemoglobin concentration and leukocyte count within the
reference ranges and a decreased platelet count. A bone marrow smear shows an
increased number of megakaryocytes. Which of the following platelet abnormalities is
the most likely cause of the findings in this patient? - Correct Answer Antibodies
directed against the glycoprotein IIb/IIIa complex
A 14-year-old girl is brought to the physician because of a 4-month history of heavy
menstrual flow. Menarche occurred at the age of 13 years. Menses have occurred at
regular 30-day intervals. She has a history of frequent nosebleeds and easy bruisability.
Her father has had problems with nosebleeds and clotting. Physical examination shows
areas of mild gum bleeding and mild ecchymoses. Laboratory studies show: Which of
the following is the most likely diagnosis? - Correct Answer Von willebrand disease
A previously healthy 20-year-old woman comes to the emergency department because
of a 2-week history of fever, shaking chills, headaches, fatigue, and joint and muscle
pain. She recently spent the summer working as a lifeguard on Long Island, New York.
She has never traveled outside the USA. She underwent splenectomy for injuries
sustained in a motor vehicle collision at the age of 6 years. Her temperature is 39.1°C
(102.4°F). Physical examination shows no other abnormalities. A peripheral blood
smear shows small intraerythrocytic rings; the result of a polymerase chain reaction test
for Plasmodium is negative. This patient most likely acquired the causal organism via a
bite from which of the following? - Correct Answer Tick
A 25-year-old woman comes to the physician for a routine follow-up examination. Two
years ago, she underwent splenectomy as a result of injuries sustained in a motor
vehicle collision. Physical examination shows no abnormalities. A complete blood count
shows target erythrocytes. This finding is most likely the result of loss of function of
which of the following portions of the spleen? - Correct Answer Red pulp
A 55-year-old woman develops a headache, temperatures to 40°C (104 °F), a stiff neck,
and confusion. Her spleen was removed due to injuries sustained in a motor vehicle
collision 7 months ago. Which of the following organisms is most likely to be cultured
from the patient's cerebrospinal fluid? - Correct Answer Streptococcus pneumonia
A 35-year-old metal worker collapses after exposure to an unknown chemical at a
factory. He is dyspneic but is noncyanotic and smells of burnt almonds. The most
appropriate next step is to administer which of the following? - Correct Answer Amyl
nitrite
2023
A 67-year-old woman is hospitalized because of abdominal pain and persistent copious
vomiting for 24 hours. Two weeks ago, she was hospitalized for treatment of atrial
fibrillation; after cardioversion to a normal sinus rhythm, she began treatment with
warfarin. Yesterday, at a follow-up visit, her INR was 6 (?? normal), and her medication
was discontinued. She takes no other medications. Her temperature is 37°C (98.6°F),
pulse is 120/min and regular, respirations are 20/min, and blood pressure is 100/78 mm
Hg. The abdomen is distended and moderately tender; there is voluntary guarding in the
epigastrium (??? source of pain) There are no masses, organomegaly, or obvious
hernias. Rectal examination shows no abnormalities. Test of the stool for occult blood is
negative. Her hemoglobin concentration has decreased from 13 g/dL yesterday to 7.8
g/dL today. An ECG shows a normal sinus rhythm. Which of the following is the most
likely explanation for this patient's abdominal symptoms? - Correct Answer Intramural
hematoma of the proximal small bowel
A 4-year-old boy is brought to the physician by his parents because of fatigue and
irritability over the past 2 months. The family visited relatives in rural Louisiana 5 months
ago where the patient ran around barefoot. The child is active and appears normal. The
conjunctivae are pale. Laboratory studies include a normal leukocyte count with 15%
eosinophils. A stool preparation discloses the parasite egg shown. Which of the
following is the most likely cause of fatigue and irritability in this patient? - Correct
Answer Microcytic anemia
Two days after beginning primaquine for malaria prophylaxis, a 17-year-old African
American boy is brought to the physician because of dark urine and yellowing of his
eyes. His pulse is 88/min, respirations are 12/min, and blood pressure is 124/68 mm
Hg. Examination shows scleral icterus and pale mucous membranes. His hemoglobin
concentration is 10 g/dL. A blood smear shows erythrocyte fragments and Heinz bodies.
Which of the following is the most likely explanation for these findings? - Correct
Answer Deficiency of glucose 6-phosphate dehydrogenase
A one-day-old newborn male is found to have hemolytic disease of the newborn. Both
parents are Rh-positive, mother is positive for IgG isohemagglutinins, while father is
negative. Which of the following parental blood types most likely caused this condition?
- Correct Answer Mother: O and Father: AB
One week after receiving 4 units of packed red blood cells for acute hemorrhage due to
a gunshot wound, a 17-year-old male develops fatigue, jaundice. Laboratory results
show the following:Hemoglobin 8.8 g/dL Hematocrit 28%, Serum total bilirubin 5 mg/dL
Serum lactate dehydrogenase 120 U/L. Liver and kidney function tests are otherwise
within normal limits. Which of the following is the most appropriate next step in
diagnosis? - Correct Answer Direct and indirect antiglobulin (Coombs) tests
,A 6-month-old boy is brought to the physician because of left knee swelling for 24
hours. Three months ago, he had three large hematomas on his forehead that resolved
without treatment (??). His two sisters and his mother have no history of similar
symptoms. His mother's maternal uncle and her brother died (x-linked recessive) before
the age of 30 years of massive cerebral hemorrhages. Physical examination shows
deep ecchymosis over the buttocks and severe swelling of the left knee. The most likely
explanation for these findings is a deficiency of which of the following? - Correct
Answer Factor VIII (antihemophilic factor)
Three days after undergoing elective laparoscopic cholecystectomy for cholelithiasis, a
42-year-old woman has the onset of hematomas at all surgical sites. She was treated
for deep venous thrombosis 3 years ago but was not taking any medications at the time
of this admission. Results of preoperative laboratory studies were within the reference
range. Prior to the operation, she received heparin and underwent application of
compression stockings. Her initial postoperative course was uncomplicated. Heronly
medication is ibuprofen. She is 163 cm (5 ft 4 in) tall and weighs 87 kg (192 lb); BMI is
33 kg/m2. Her temperature is 37.3°C(99.2°F), pulse is 94/min, respirations are 16/min,
and blood pressure is 112/74 mm Hg. Examination shows mild hematomas at all
surgical sites. The abdomen is soft and nontender. There is no organomegaly. Bowel
sounds are normal. Laboratory studies show:Hemoglobin 10.3 g/dL Hematocrit
30%Leukocyte count 12,000/mm3 Platelet count 45,000/mm3 Which of the following is
the most likely cause of this patient's current findings? - Correct Answer Heparin-
induced thrombocytopenia
A 3-year-old girl with Down syndrome is brought to the physician because of a 1-week
history of frequent nosebleeds, decreased appetite, and lethargy. She takes no
medications. Her temperature is 38°C (100.4°F), pulse is 100/min, respirations are
20/min,and blood pressure is 80/45 mm Hg. Examination shows no other abnormalities
except for pallor. Laboratory studies show:Hemoglobin 6.5 g/dL Hematocrit
19%Leukocyte count 100,000/mm3 Segmented neutrophils 15%Atypical lymphocytes
85%Platelet count 45,000/mm3 Which of the following is the most likely mechanism of
these laboratory findings? - Correct Answer Infiltration of bone marrow by leukemic
blasts
A 30-year-old woman, gravida 2, para 1, comes for her first prenatal visit at 26 weeks'
gestation. Uterine size is greater than expected for dates. Ultrasonography shows fetal
hydrops. Which of the following is the most appropriate next step in diagnosis? -
Correct Answer Maternal Rh status with antibody screening
A 65-year-old man has had increasingly severe headaches and diffuse muscle aches
during the past 3 months. He also has a 1-month history of jaw pain when chewing food
and decreasing visual acuity in his left eye. His temperature is 38°C (100.4°F). Visual
acuity in his left eye is 20/100, and the left optic disc is slightly atrophic. His muscle
strength is normal. Which of the following tests should be obtained next? - Correct
Answer Measurement of erythrocyte sedimentation rate
,A 10-year-old boy has had anemia since birth. His spleen is five times normal size.
Splenectomy is indicated if the anemia is caused by which of the following disorders? -
Correct Answer Hereditary spherocytosis
A previously healthy 72-year-old man is brought to the physician because of weakness
and fatigue. His hemoglobin concentration is 9.2 g/dl, leukocyte count is 5400/mm3, and
platelet count is 350,000/mm3. A peripheral blood smear is shown. Which of the
following is the most likely cause of these findings? - Correct Answer Gastrointestinal
blood loss
A 48-year-old man comes to the physician because of increasing bronzing of his skin,
weakness, and fatigue during the past 3 months. Physical examination shows bronzing
of the skin, hepatomegaly, and small testes. Serum studies show: Which of the
following best explains the findings in this patient? - Correct Answer Increased
intestinal iron absorption
A 3-year-old boy and his 5-year-old brother bruise easily and have recurrent
hemarthrosis. Both parents are healthy, but the mother has two younger brothers with
the same symptoms and a maternal uncle who died at 8 years of age after mild head
trauma. Partial thromboplastin time is prolonged. The most likely defect involves which
of the following? - Correct Answer Factor VIII (antihemophilic factor)
An 81-year-old woman is admitted to the hospital because of a massive pulmonary
embolism from a deep venous thrombosis. Her platelet count is 160,000/mm3.
Appropriate pharmacotherapy is started. One week later, her platelet count is
55,000/mm3. The thrombocytopenia was most likely caused by a drug with which of the
following mechanisms of action? - Correct Answer Potentiates the action of
antithrombin III
A 62-year-old woman with recurrent pulmonary emboli comes to the physician for a
follow-up examination. Physical examination shows no abnormalities. Laboratory
studies show a prothrombin time of 12 seconds. Warfarin therapy is begun. Which of
the following clotting factors is the first to be decreased by 50% after the initiation of
therapy? - Correct Answer VII (proconvertin)
A 40-year-old man is evaluated because his skin is extremely sensitive to sunlight.
Exposure to the sun causes the formation of vesicles and blisters on the skin, which
frequently take weeks to heal. He is diagnosed with a disorder caused by the increased
synthesis of compounds in the skin that are subject to excitation by visible light. Which
of the following biochemical pathways is most likely defective in this patient? - Correct
Answer Heme synthesis
A 53-year-old man, who recently returned from Africa, has fever, headache, and
abdominal discomfort. He received appropriate vaccinations prior to the trip. His
temperature is 39.4°C (103°F). Physical examination shows no other abnormalities. A
, Wright-stained peripheral blood smear is shown. Which of the following is the most
likely diagnosis? - Correct Answer Malaria
A 10-year-old boy is brought to the physician because of a 4-day history of nosebleeds
and easy bruising. Three weeks ago, he had an upper respiratory tract infection.
Physical examination shows ecchymoses over the upper and lower extremities.
Laboratory studies show a hemoglobin concentration and leukocyte count within the
reference ranges and a decreased platelet count. A bone marrow smear shows an
increased number of megakaryocytes. Which of the following platelet abnormalities is
the most likely cause of the findings in this patient? - Correct Answer Antibodies
directed against the glycoprotein IIb/IIIa complex
A 14-year-old girl is brought to the physician because of a 4-month history of heavy
menstrual flow. Menarche occurred at the age of 13 years. Menses have occurred at
regular 30-day intervals. She has a history of frequent nosebleeds and easy bruisability.
Her father has had problems with nosebleeds and clotting. Physical examination shows
areas of mild gum bleeding and mild ecchymoses. Laboratory studies show: Which of
the following is the most likely diagnosis? - Correct Answer Von willebrand disease
A previously healthy 20-year-old woman comes to the emergency department because
of a 2-week history of fever, shaking chills, headaches, fatigue, and joint and muscle
pain. She recently spent the summer working as a lifeguard on Long Island, New York.
She has never traveled outside the USA. She underwent splenectomy for injuries
sustained in a motor vehicle collision at the age of 6 years. Her temperature is 39.1°C
(102.4°F). Physical examination shows no other abnormalities. A peripheral blood
smear shows small intraerythrocytic rings; the result of a polymerase chain reaction test
for Plasmodium is negative. This patient most likely acquired the causal organism via a
bite from which of the following? - Correct Answer Tick
A 25-year-old woman comes to the physician for a routine follow-up examination. Two
years ago, she underwent splenectomy as a result of injuries sustained in a motor
vehicle collision. Physical examination shows no abnormalities. A complete blood count
shows target erythrocytes. This finding is most likely the result of loss of function of
which of the following portions of the spleen? - Correct Answer Red pulp
A 55-year-old woman develops a headache, temperatures to 40°C (104 °F), a stiff neck,
and confusion. Her spleen was removed due to injuries sustained in a motor vehicle
collision 7 months ago. Which of the following organisms is most likely to be cultured
from the patient's cerebrospinal fluid? - Correct Answer Streptococcus pneumonia
A 35-year-old metal worker collapses after exposure to an unknown chemical at a
factory. He is dyspneic but is noncyanotic and smells of burnt almonds. The most
appropriate next step is to administer which of the following? - Correct Answer Amyl
nitrite
