NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
3 types of benign colonic polyps - ansHyperplastic polyps (saw-toothed pattern)
Juvenile polyp
Peutz-Jeghers polyps
3 types of neoplastic polyps (adenoma) - ansTubular adenoma (pedunculated, most common)
Tubulovillous adenoma (pedunculated)
Villous adenoma (sessile, most malignant potential)
6yo boy from Russia with unstable gait and incoordination for 2 weeks. Pale, bulky stools for 4 years and
two episodes of bacterial pneumonia and chronic cough since age 1 year. 3%ile for height/weight. Neuro
exam shows ataxia, no DTRs, loss of proprioception. Stool shows inc fat concentration. Vitamin deficient?
- ansE
fragility of erythrocytes (hemolytic anemia)
muscle weakness
neurodysfunction
poor joint sensation and ataxia
6yo boy with recurrent systemic infections with Neisseria meningitidis but healthy otherwise. What lab test
is likely to be abnormal in this child? - ansTotal hemolytic complement concentration
C5-C9 deficiency causes failure of formation of membrane attack complex (MAC) which causes
susceptibility to Neisseria
8 weeks after recovering from pneumococcal pneumonia, CXR shows no abnormalities. What allowed
this resolution to occur? - ansMaintenance of basement membrane integrity
14yo boy with daily headaches (bilateral aching in temples). "Not been himself", more confused, forgetting
things. Clumsy with frequent falls. Broad-based ataxic gait. Slow to answer questions.
Chronic abuse of what substance cause these symptoms? - ansInhaled glue
15yo girl emigrated from India and with several lesions on neck for 2 weeks. Physical exam shows
hypopigmented, hypoesthetic area on left side of forehead and 4-cm lesions on neck. Biopsy shows acid-
fast bacilli. Best explanation why the organism results in dermal rather than visceral infections? -
ansTemperature sensitivity
Mycobacterium leprae is non-motile acid-fast bacili that likes cool temperature. Reservoirs is amadillos.
Cutaneous nodules with hypopigmentation, erythematous plaques with central hypopigmentation,
peripheral neuropathy, lion-like facies
16yo girl with intermittent fainting while standing. Plasma studies show undetectable NE/Epi
concentration and marked increase in dopamine concentration when rising from a supine position to
standing
Deficiency in what enzyme? - ansDopamine B-hydroxylase
A rare form of dysautonomia. Dopamine is released as a false neurotransmitter in place of NE and Epi
,NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
17yo woman just ran a marathon. 1 day later has SOB, weakness, muscle tenderness, fever, tachypnea,
edema, pulmonary crackles. Cr 4, UA with 3+ protein and 4+ hemoglobin
Release of what substance causes her symptoms? - ansMyoglobin
Rhabdomyelysis -- Breakdown of muscles releases intracellular contents. Myoglobin causes renal tubular
obstruction causing AKI, with proteinuria and myoglobinuria (which can be mistaken for hemoglobinuria)
25yo F with 3-year hx of irregular menses. Menarche was at age of 14 years. PE shows increased hair
growth on the face and chest. Pelvic exam shows clitoromegaly and a normal-appearing uterus. Serum
shows increased 17-hydroxyprogesterone and androstenedione. Deficiency of? - ans21-hydroxylase
"Congenital adrenal hyperplasia"
25yo woman 6-month history of joint pain poorly responsive to aspirin. Physical exam: bilateral swelling of
proximal interphalangeal joints, metacarpophalangeal joints, and wrists; weakness of grasp. Small
nodules palpated beneath skin around joints of fingers. Dx? - ansRheumatoid arthritis
32yo M with 3-month hx of swelling and breast tenderness. Receiving thyroid hormone and steroid
replacements since removal of pituitary adenoma 2 years ago. Began hCG injections 4 months ago. Most
likely binding site of hCG causing gynecomastia? - ansTesticle --> estradiol production
35yo man with recurrent sinusitis and bronchitis throughout his life. One sister has similar history. Married
with no children. Cardiac exam shows PMI on the right midclavicular 4th intercostal, hepatic margin on
the left. Endoscopy shows nasal polyps, biopsy shows thickened, ciliated, pseudostratified epithelium with
small patches of squamous metaplasia and mild lymphoid infiltration
What disease and what structure would be missing on electron microscopy? - ansPrimary ciliary
dyskinesia/Kartagener syndrome
Dynein arms is missing or damaged --> cilia not working
Triad of: situs inversus, chronic sinusitis, bronchiectasis
For males, reduced fertility because low sperm motility
38yo M with 1-week hx of watery, itchy eyes and a runny nose. Physical shows inflamed nasal mucosa.
No congestion in lower lung. Pharmacotherapy? - ansLoratadine
First gen H1 blocker has strong sedative action and anticholinergic effects, and not recommended for
people operating heavy machineries. Second gen H1 blocker is non-sedative (Loratidine, Cetirizine,
Azelastine, Fexofenadine)
40yo M with extreme sensitivity to sunlight. Exposure to sun causes formation of vesicles and blisters on
skin, which takes weeks to heal. He is diagnosed with a disorder caused by increased synthesis of
compounds in the skin that are subject to excitation by visible light.
What pathway is defective? - ansHeme synthesis
Porphyria cutanea tarda is caused by defect in uroporphyrinogen decarboxylase in heme synthesis -->
accumulation of uroporphyrin 1
,NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
Sx: blistering cutaneous photosensitivity caused by hepatotoxic triggers (alcohol, estrogens). Most
common type or porphyria
40yo M with interstitial pulmonary fibrosis has greater maximal expiratory flow rate than predicted. Which
best explains this? - ansIncreased radial traction on airway
The connective tissue that surrounds the airways of the lungs are called the parenchyma. This forms a
sort of scaffold around the airways, keeping them open with a force known as "radial traction". Radial
traction is the "spring" that bounce back to force air out. Fibrosis increases radial traction
44-year-old woman comes to the physician for a follow-up examination after two separate Pap smears
showed atypical squamous cells of undetermined significance. Results of a molecular diagnostic test
show the presence of the viral E6 protein of human papillomavirus. This protein is known to promote cell
growth and malignancy by causing cellular p53 protein degradation. This degradation most likely begins
when the p53 protein is targeted to which of the following types of cellular enzymes? - ansUbiquitin ligase
protein degradation
56yo M 4 hours after sudden onset of uncontrollable irregular movements of the left side of the body. PE
shows flailing movements of the proximal appendicular muscles on the left. Nuclei damaged? - ansRight
subthalamic
Hemiballismus is flinging/flailing movement of one side, caused by damage to the CONTRALATERAL
subthalamic nucleus. Likely 2/2 to lacunar infarct
60yo M flow cytometry of peripheral lymphocytes show:
CD3 50%
CD4 40%
CD8 10%
CD20 50%
Surface kappa 47%
Surface lamba 3%
What is predictive of a clonal lymphoid proliferation? - anssurface kappa:surface lambda ratio
Each plasma cell can only make either kappa or lambda. Normal ratio about 3:1. If one is much higher
than the other, that means there is MONOCLONAL proliferation (instead of the normal polyclonal), such
as in multiple myeloma
60yo M shipyard worker with progressive SOB pas 3 months. Xray of chest shows reticulonodular
pulmonary infiltrates consistent with interstitial fibrosis. Microscopic exam of sputum shows occasional
elongate structures (golden-brown fusiform rods). The fibrosis was most likely initiated by interaction of
these structures with which cell type? - ansAlveolar macrophage
Asbestosis - increased risk of bronchogenic carcinoma and mesothelioma
60yo M sudden onset of acute abdominal pain and tenderness, n/v, bloody diarrhea for 2 hours. History
of cirrhosis and HCC. BP 99/50. Rigid abdominal pain with loss of bowel sounds. Half of small intestine is
found to have a dark purple-red hemorrhagic appearance. What is the cause? - ansMesenteric venous
thrombosis
, NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
60yo peanut farmer in China with sxs of hepatocellular carcinoma. No alcohol, negative Hep B/C. What is
the cause? - ansAflatoxin
(released by Aspergillus, contained in maize, peanuts, cotton seeds, tree nuts)
62yo M with pericardial friction rub 3 days after acute myocardial infarction. Cause of rub? - ansFibrinous
pericarditis (Dressler syndrome)
65yo M emigrated from Brazil with 8-month history of shortness of breath and fatigue, edema of lower ext.
CXR shows cardiomegaly. endomyocardial biopsy specimen shows myofiber necrosis with a mixed
inflammatory infiltrate of PMNs, T lymphos, m.phages, and eosinophils. Causal org? - ansTrypanosoma
cruzi
65yo woman with progressive vulvar itching not relieved with miconazole. Atrophy of labia minora and
thin, parchment-like skin over vulva and around anus. Dx? - ansLichen sclerosus
chronic inflammatory disease with characteristic white, atrophic plaques. Tx: topical steroids
68yo M difficulty swallowing solids, with history of dilated cardiomyopathy. Xray of esophagus with barium
show indentation and posterior displacement of the esophagus. Enlargement of which heart chamber is
the cause? - ansLeft atrium
70yo M from China has poorly differentiated monoclonal carcinoma of the nasopharynx. DNA probes of
neoplastic cells most likely to detect what viral genome? - ansEBV
A farmer is taking itraconazole for histoplasmosis acquired after contact with chicken coop. He still shows
persistent symptoms despite 4 wks of therapy. Other medications include: HTCZ, enalapril, atenolol,
omeprazole, metoclopramide.
What drug causes lack of effect of itraconazole? - ansOmeprazole
Itraconazole and other triazole antifungals comes in a capsule that requires acidic pH in the stomach to
be absorbed in the duodenum. Omeprazole reduces acids --> low absorption of itraconazole
A pregnant women with abd pain for 12 hrs and upper quadrant pain. her labs show decreased platelets
and hemoglobin and elevated liver enzymes. what would you expect on peripheral blood smear? -
ansSchistocytes
HELLP syndrome is preeclampsia Hemolysis, Elevated LFTs, Low Platelets. Peripheral blood smear
shows schistocytes due to hemolysis
Alendronate MOA - ansinhibition of osteoclast-mediation bone resorption
Blood agglutination is caused by what antibody isotype? - ansIgM
Boy with anemia since birth with splenomegaly. Splenectomy is indicated if the anemia is caused by
which disorders? - ansHereditary spherocytosis
Cyclophosphamide MOA - ansAlkylating agent --> crosslinking of DNA --> inhibits DNA replication
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
3 types of benign colonic polyps - ansHyperplastic polyps (saw-toothed pattern)
Juvenile polyp
Peutz-Jeghers polyps
3 types of neoplastic polyps (adenoma) - ansTubular adenoma (pedunculated, most common)
Tubulovillous adenoma (pedunculated)
Villous adenoma (sessile, most malignant potential)
6yo boy from Russia with unstable gait and incoordination for 2 weeks. Pale, bulky stools for 4 years and
two episodes of bacterial pneumonia and chronic cough since age 1 year. 3%ile for height/weight. Neuro
exam shows ataxia, no DTRs, loss of proprioception. Stool shows inc fat concentration. Vitamin deficient?
- ansE
fragility of erythrocytes (hemolytic anemia)
muscle weakness
neurodysfunction
poor joint sensation and ataxia
6yo boy with recurrent systemic infections with Neisseria meningitidis but healthy otherwise. What lab test
is likely to be abnormal in this child? - ansTotal hemolytic complement concentration
C5-C9 deficiency causes failure of formation of membrane attack complex (MAC) which causes
susceptibility to Neisseria
8 weeks after recovering from pneumococcal pneumonia, CXR shows no abnormalities. What allowed
this resolution to occur? - ansMaintenance of basement membrane integrity
14yo boy with daily headaches (bilateral aching in temples). "Not been himself", more confused, forgetting
things. Clumsy with frequent falls. Broad-based ataxic gait. Slow to answer questions.
Chronic abuse of what substance cause these symptoms? - ansInhaled glue
15yo girl emigrated from India and with several lesions on neck for 2 weeks. Physical exam shows
hypopigmented, hypoesthetic area on left side of forehead and 4-cm lesions on neck. Biopsy shows acid-
fast bacilli. Best explanation why the organism results in dermal rather than visceral infections? -
ansTemperature sensitivity
Mycobacterium leprae is non-motile acid-fast bacili that likes cool temperature. Reservoirs is amadillos.
Cutaneous nodules with hypopigmentation, erythematous plaques with central hypopigmentation,
peripheral neuropathy, lion-like facies
16yo girl with intermittent fainting while standing. Plasma studies show undetectable NE/Epi
concentration and marked increase in dopamine concentration when rising from a supine position to
standing
Deficiency in what enzyme? - ansDopamine B-hydroxylase
A rare form of dysautonomia. Dopamine is released as a false neurotransmitter in place of NE and Epi
,NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
17yo woman just ran a marathon. 1 day later has SOB, weakness, muscle tenderness, fever, tachypnea,
edema, pulmonary crackles. Cr 4, UA with 3+ protein and 4+ hemoglobin
Release of what substance causes her symptoms? - ansMyoglobin
Rhabdomyelysis -- Breakdown of muscles releases intracellular contents. Myoglobin causes renal tubular
obstruction causing AKI, with proteinuria and myoglobinuria (which can be mistaken for hemoglobinuria)
25yo F with 3-year hx of irregular menses. Menarche was at age of 14 years. PE shows increased hair
growth on the face and chest. Pelvic exam shows clitoromegaly and a normal-appearing uterus. Serum
shows increased 17-hydroxyprogesterone and androstenedione. Deficiency of? - ans21-hydroxylase
"Congenital adrenal hyperplasia"
25yo woman 6-month history of joint pain poorly responsive to aspirin. Physical exam: bilateral swelling of
proximal interphalangeal joints, metacarpophalangeal joints, and wrists; weakness of grasp. Small
nodules palpated beneath skin around joints of fingers. Dx? - ansRheumatoid arthritis
32yo M with 3-month hx of swelling and breast tenderness. Receiving thyroid hormone and steroid
replacements since removal of pituitary adenoma 2 years ago. Began hCG injections 4 months ago. Most
likely binding site of hCG causing gynecomastia? - ansTesticle --> estradiol production
35yo man with recurrent sinusitis and bronchitis throughout his life. One sister has similar history. Married
with no children. Cardiac exam shows PMI on the right midclavicular 4th intercostal, hepatic margin on
the left. Endoscopy shows nasal polyps, biopsy shows thickened, ciliated, pseudostratified epithelium with
small patches of squamous metaplasia and mild lymphoid infiltration
What disease and what structure would be missing on electron microscopy? - ansPrimary ciliary
dyskinesia/Kartagener syndrome
Dynein arms is missing or damaged --> cilia not working
Triad of: situs inversus, chronic sinusitis, bronchiectasis
For males, reduced fertility because low sperm motility
38yo M with 1-week hx of watery, itchy eyes and a runny nose. Physical shows inflamed nasal mucosa.
No congestion in lower lung. Pharmacotherapy? - ansLoratadine
First gen H1 blocker has strong sedative action and anticholinergic effects, and not recommended for
people operating heavy machineries. Second gen H1 blocker is non-sedative (Loratidine, Cetirizine,
Azelastine, Fexofenadine)
40yo M with extreme sensitivity to sunlight. Exposure to sun causes formation of vesicles and blisters on
skin, which takes weeks to heal. He is diagnosed with a disorder caused by increased synthesis of
compounds in the skin that are subject to excitation by visible light.
What pathway is defective? - ansHeme synthesis
Porphyria cutanea tarda is caused by defect in uroporphyrinogen decarboxylase in heme synthesis -->
accumulation of uroporphyrin 1
,NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
Sx: blistering cutaneous photosensitivity caused by hepatotoxic triggers (alcohol, estrogens). Most
common type or porphyria
40yo M with interstitial pulmonary fibrosis has greater maximal expiratory flow rate than predicted. Which
best explains this? - ansIncreased radial traction on airway
The connective tissue that surrounds the airways of the lungs are called the parenchyma. This forms a
sort of scaffold around the airways, keeping them open with a force known as "radial traction". Radial
traction is the "spring" that bounce back to force air out. Fibrosis increases radial traction
44-year-old woman comes to the physician for a follow-up examination after two separate Pap smears
showed atypical squamous cells of undetermined significance. Results of a molecular diagnostic test
show the presence of the viral E6 protein of human papillomavirus. This protein is known to promote cell
growth and malignancy by causing cellular p53 protein degradation. This degradation most likely begins
when the p53 protein is targeted to which of the following types of cellular enzymes? - ansUbiquitin ligase
protein degradation
56yo M 4 hours after sudden onset of uncontrollable irregular movements of the left side of the body. PE
shows flailing movements of the proximal appendicular muscles on the left. Nuclei damaged? - ansRight
subthalamic
Hemiballismus is flinging/flailing movement of one side, caused by damage to the CONTRALATERAL
subthalamic nucleus. Likely 2/2 to lacunar infarct
60yo M flow cytometry of peripheral lymphocytes show:
CD3 50%
CD4 40%
CD8 10%
CD20 50%
Surface kappa 47%
Surface lamba 3%
What is predictive of a clonal lymphoid proliferation? - anssurface kappa:surface lambda ratio
Each plasma cell can only make either kappa or lambda. Normal ratio about 3:1. If one is much higher
than the other, that means there is MONOCLONAL proliferation (instead of the normal polyclonal), such
as in multiple myeloma
60yo M shipyard worker with progressive SOB pas 3 months. Xray of chest shows reticulonodular
pulmonary infiltrates consistent with interstitial fibrosis. Microscopic exam of sputum shows occasional
elongate structures (golden-brown fusiform rods). The fibrosis was most likely initiated by interaction of
these structures with which cell type? - ansAlveolar macrophage
Asbestosis - increased risk of bronchogenic carcinoma and mesothelioma
60yo M sudden onset of acute abdominal pain and tenderness, n/v, bloody diarrhea for 2 hours. History
of cirrhosis and HCC. BP 99/50. Rigid abdominal pain with loss of bowel sounds. Half of small intestine is
found to have a dark purple-red hemorrhagic appearance. What is the cause? - ansMesenteric venous
thrombosis
, NBME CBSE ACTUAL EXAM 200 QUESTIONS AND
ANSWERS LATEST (USMLE STEP 1) MEDICAL
EXAMINATION LATEST UPDATED MAY 2025 A+
GRADE.
60yo peanut farmer in China with sxs of hepatocellular carcinoma. No alcohol, negative Hep B/C. What is
the cause? - ansAflatoxin
(released by Aspergillus, contained in maize, peanuts, cotton seeds, tree nuts)
62yo M with pericardial friction rub 3 days after acute myocardial infarction. Cause of rub? - ansFibrinous
pericarditis (Dressler syndrome)
65yo M emigrated from Brazil with 8-month history of shortness of breath and fatigue, edema of lower ext.
CXR shows cardiomegaly. endomyocardial biopsy specimen shows myofiber necrosis with a mixed
inflammatory infiltrate of PMNs, T lymphos, m.phages, and eosinophils. Causal org? - ansTrypanosoma
cruzi
65yo woman with progressive vulvar itching not relieved with miconazole. Atrophy of labia minora and
thin, parchment-like skin over vulva and around anus. Dx? - ansLichen sclerosus
chronic inflammatory disease with characteristic white, atrophic plaques. Tx: topical steroids
68yo M difficulty swallowing solids, with history of dilated cardiomyopathy. Xray of esophagus with barium
show indentation and posterior displacement of the esophagus. Enlargement of which heart chamber is
the cause? - ansLeft atrium
70yo M from China has poorly differentiated monoclonal carcinoma of the nasopharynx. DNA probes of
neoplastic cells most likely to detect what viral genome? - ansEBV
A farmer is taking itraconazole for histoplasmosis acquired after contact with chicken coop. He still shows
persistent symptoms despite 4 wks of therapy. Other medications include: HTCZ, enalapril, atenolol,
omeprazole, metoclopramide.
What drug causes lack of effect of itraconazole? - ansOmeprazole
Itraconazole and other triazole antifungals comes in a capsule that requires acidic pH in the stomach to
be absorbed in the duodenum. Omeprazole reduces acids --> low absorption of itraconazole
A pregnant women with abd pain for 12 hrs and upper quadrant pain. her labs show decreased platelets
and hemoglobin and elevated liver enzymes. what would you expect on peripheral blood smear? -
ansSchistocytes
HELLP syndrome is preeclampsia Hemolysis, Elevated LFTs, Low Platelets. Peripheral blood smear
shows schistocytes due to hemolysis
Alendronate MOA - ansinhibition of osteoclast-mediation bone resorption
Blood agglutination is caused by what antibody isotype? - ansIgM
Boy with anemia since birth with splenomegaly. Splenectomy is indicated if the anemia is caused by
which disorders? - ansHereditary spherocytosis
Cyclophosphamide MOA - ansAlkylating agent --> crosslinking of DNA --> inhibits DNA replication
