STEP 2 CK NBME REVIEW QUESTIONS AND ANSWERS
2026/2027 | Latest Update | Complete Solution with Detailed
Rationales | USMLE Step 2 Prep | Pass Guaranteed - A+
Graded
BLOCK 1: QUESTIONS 1-40
Internal Medicine, Surgery, Multisystem Processes
Q1: A 68-year-old man with a 40-pack-year smoking history presents with worsening
dyspnea on exertion, chronic cough, and 15-pound weight loss over 3 months. Chest
X-ray shows a 4 cm right hilar mass with right paratracheal lymphadenopathy. CT-guided
biopsy reveals small cell lung cancer. Brain MRI is negative for metastases. His ECOG
performance status is 1. What is the most appropriate next step in management?
A. Surgical resection of the hilar mass
B. Concurrent chemoradiation therapy
C. Platinum-based chemotherapy alone
D. Prophylactic cranial irradiation
E. Targeted therapy with osimertinib
Correct Answer: B
Rationale: 68-year-old smoker with limited-stage small cell lung cancer (SCLC) confined
to hemithorax and ipsilateral mediastinal nodes → concurrent chemoradiation is
standard of care. [CORRECT]
,SCLC is characterized by rapid growth, early metastasis, and initial chemosensitivity.
Limited-stage disease (confined to hemithorax and ipsilateral
mediastinal/supraclavicular nodes, negative brain MRI) is treated with concurrent
platinum-etoposide chemotherapy and thoracic radiation therapy starting early in cycle
1 or 2. This approach yields 5-year survival rates of 20-25% versus 10-15% with
sequential therapy.
Distractor Analysis:
● A: Surgery has no role in SCLC; this is a medical oncology emergency requiring
systemic therapy
● C: Chemotherapy alone is inferior to concurrent chemoradiation for limited-stage
disease
● D: Prophylactic cranial irradiation follows response to initial therapy, not as first
step
● E: Osimertinib targets EGFR mutations in adenocarcinoma, not SCLC
Test-taking Strategy: "Hilar mass + smoker + rapid symptoms" → think SCLC.
Distinguish limited vs. extensive stage by imaging. Limited stage = concurrent
chemoradiation is the only answer that improves survival over chemotherapy alone.
Q2: A 24-year-old woman presents with 2 weeks of fatigue, joint pain in her hands and
knees, and a facial rash that worsens with sun exposure. Physical exam reveals malar
erythema sparing the nasolabial folds, synovitis of the MCP and PIP joints, and oral
ulcers. Labs show WBC 3,200/μL, Hgb 10.2 g/dL, platelets 98,000/μL, creatinine 1.4
mg/dL, and urinalysis with 2+ protein and RBC casts. ANA is positive at 1:640. What is
the most specific test to confirm the diagnosis?
A. Anti-double stranded DNA (anti-dsDNA) antibodies
B. Anti-Smith (anti-Sm) antibodies
,C. Anti-histone antibodies
D. Complement levels (C3, C4)
E. Anti-Ro/SSA antibodies
Correct Answer: B
Rationale: 24-year-old woman with malar rash, photosensitivity, oral ulcers, arthritis,
cytopenias, and renal involvement with active sediment → systemic lupus
erythematosus (SLE); anti-Smith is pathognomonic. [CORRECT]
This patient meets 6 of 11 ACR criteria (malar rash, photosensitivity, oral ulcers,
arthritis, renal disorder, hematologic disorder). While anti-dsDNA is highly sensitive for
SLE, anti-Smith antibodies are 99% specific—virtually diagnostic when present.
Anti-dsDNA correlates with disease activity and renal involvement but lacks specificity.
Distractor Analysis:
● A: Anti-dsDNA is highly sensitive (70%) and indicates disease activity/nephritis
risk, but only 50% specific
● C: Anti-histone suggests drug-induced lupus (procainamide, hydralazine) without
renal/CNS involvement
● D: Low complement indicates active disease but is not diagnostic
● E: Anti-Ro is associated with Sjögren's, neonatal lupus, and photosensitivity but
lacks specificity
Test-taking Strategy: When asked for "most specific" antibody in SLE, always choose
anti-Smith. When asked for antibody correlating with disease activity/nephritis, choose
anti-dsDNA.
Q3: A 55-year-old man with alcoholic cirrhosis presents with confusion and asterixis.
His wife reports he had a dental procedure 2 days ago and has been taking
, acetaminophen for pain. On exam, he is oriented only to person. Labs: ammonia 180
μmol/L (normal <35), INR 1.8, bilirubin 4.2 mg/dL. What is the most appropriate initial
pharmacotherapy?
A. Lactulose enemas
B. Rifaximin
C. Neomycin
D. L-ornithine-L-aspartate
E. Zinc supplementation
Correct Answer: A
Rationale: 55-year-old cirrhotic with acute confusional state, asterixis, elevated
ammonia, and precipitant (infection from dental procedure) → hepatic encephalopathy;
lactulose is first-line to reduce ammonia absorption. [CORRECT]
Hepatic encephalopathy (HE) is a neuropsychiatric syndrome caused by gut-derived
nitrogenous compounds. Lactulose (non-absorbable disaccharide) acidifies colonic
contents, converting ammonia to non-absorbable ammonium and promoting excretion.
For acute overt HE, lactulose enemas work faster than oral administration when ileus or
altered mental status limits PO intake.
Distractor Analysis:
● B: Rifaximin is second-line/add-on therapy for recurrent HE, not initial
monotherapy
● C: Neomycin is rarely used due to nephrotoxicity and ototoxicity; rifaximin has
replaced it
● D: L-ornithine-L-aspartate is investigational and not standard of care
● E: Zinc deficiency can worsen HE but is adjunctive, not initial therapy
2026/2027 | Latest Update | Complete Solution with Detailed
Rationales | USMLE Step 2 Prep | Pass Guaranteed - A+
Graded
BLOCK 1: QUESTIONS 1-40
Internal Medicine, Surgery, Multisystem Processes
Q1: A 68-year-old man with a 40-pack-year smoking history presents with worsening
dyspnea on exertion, chronic cough, and 15-pound weight loss over 3 months. Chest
X-ray shows a 4 cm right hilar mass with right paratracheal lymphadenopathy. CT-guided
biopsy reveals small cell lung cancer. Brain MRI is negative for metastases. His ECOG
performance status is 1. What is the most appropriate next step in management?
A. Surgical resection of the hilar mass
B. Concurrent chemoradiation therapy
C. Platinum-based chemotherapy alone
D. Prophylactic cranial irradiation
E. Targeted therapy with osimertinib
Correct Answer: B
Rationale: 68-year-old smoker with limited-stage small cell lung cancer (SCLC) confined
to hemithorax and ipsilateral mediastinal nodes → concurrent chemoradiation is
standard of care. [CORRECT]
,SCLC is characterized by rapid growth, early metastasis, and initial chemosensitivity.
Limited-stage disease (confined to hemithorax and ipsilateral
mediastinal/supraclavicular nodes, negative brain MRI) is treated with concurrent
platinum-etoposide chemotherapy and thoracic radiation therapy starting early in cycle
1 or 2. This approach yields 5-year survival rates of 20-25% versus 10-15% with
sequential therapy.
Distractor Analysis:
● A: Surgery has no role in SCLC; this is a medical oncology emergency requiring
systemic therapy
● C: Chemotherapy alone is inferior to concurrent chemoradiation for limited-stage
disease
● D: Prophylactic cranial irradiation follows response to initial therapy, not as first
step
● E: Osimertinib targets EGFR mutations in adenocarcinoma, not SCLC
Test-taking Strategy: "Hilar mass + smoker + rapid symptoms" → think SCLC.
Distinguish limited vs. extensive stage by imaging. Limited stage = concurrent
chemoradiation is the only answer that improves survival over chemotherapy alone.
Q2: A 24-year-old woman presents with 2 weeks of fatigue, joint pain in her hands and
knees, and a facial rash that worsens with sun exposure. Physical exam reveals malar
erythema sparing the nasolabial folds, synovitis of the MCP and PIP joints, and oral
ulcers. Labs show WBC 3,200/μL, Hgb 10.2 g/dL, platelets 98,000/μL, creatinine 1.4
mg/dL, and urinalysis with 2+ protein and RBC casts. ANA is positive at 1:640. What is
the most specific test to confirm the diagnosis?
A. Anti-double stranded DNA (anti-dsDNA) antibodies
B. Anti-Smith (anti-Sm) antibodies
,C. Anti-histone antibodies
D. Complement levels (C3, C4)
E. Anti-Ro/SSA antibodies
Correct Answer: B
Rationale: 24-year-old woman with malar rash, photosensitivity, oral ulcers, arthritis,
cytopenias, and renal involvement with active sediment → systemic lupus
erythematosus (SLE); anti-Smith is pathognomonic. [CORRECT]
This patient meets 6 of 11 ACR criteria (malar rash, photosensitivity, oral ulcers,
arthritis, renal disorder, hematologic disorder). While anti-dsDNA is highly sensitive for
SLE, anti-Smith antibodies are 99% specific—virtually diagnostic when present.
Anti-dsDNA correlates with disease activity and renal involvement but lacks specificity.
Distractor Analysis:
● A: Anti-dsDNA is highly sensitive (70%) and indicates disease activity/nephritis
risk, but only 50% specific
● C: Anti-histone suggests drug-induced lupus (procainamide, hydralazine) without
renal/CNS involvement
● D: Low complement indicates active disease but is not diagnostic
● E: Anti-Ro is associated with Sjögren's, neonatal lupus, and photosensitivity but
lacks specificity
Test-taking Strategy: When asked for "most specific" antibody in SLE, always choose
anti-Smith. When asked for antibody correlating with disease activity/nephritis, choose
anti-dsDNA.
Q3: A 55-year-old man with alcoholic cirrhosis presents with confusion and asterixis.
His wife reports he had a dental procedure 2 days ago and has been taking
, acetaminophen for pain. On exam, he is oriented only to person. Labs: ammonia 180
μmol/L (normal <35), INR 1.8, bilirubin 4.2 mg/dL. What is the most appropriate initial
pharmacotherapy?
A. Lactulose enemas
B. Rifaximin
C. Neomycin
D. L-ornithine-L-aspartate
E. Zinc supplementation
Correct Answer: A
Rationale: 55-year-old cirrhotic with acute confusional state, asterixis, elevated
ammonia, and precipitant (infection from dental procedure) → hepatic encephalopathy;
lactulose is first-line to reduce ammonia absorption. [CORRECT]
Hepatic encephalopathy (HE) is a neuropsychiatric syndrome caused by gut-derived
nitrogenous compounds. Lactulose (non-absorbable disaccharide) acidifies colonic
contents, converting ammonia to non-absorbable ammonium and promoting excretion.
For acute overt HE, lactulose enemas work faster than oral administration when ileus or
altered mental status limits PO intake.
Distractor Analysis:
● B: Rifaximin is second-line/add-on therapy for recurrent HE, not initial
monotherapy
● C: Neomycin is rarely used due to nephrotoxicity and ototoxicity; rifaximin has
replaced it
● D: L-ornithine-L-aspartate is investigational and not standard of care
● E: Zinc deficiency can worsen HE but is adjunctive, not initial therapy
