150 Practice Questions with Verified Answers and Detailed
Rationales
EXAM INSTRUCTIONS
Exam: NBME Pathology Final Exam 2026–2027
Format: Multiple Choice, Clinical Vignettes
Content Areas: Cell Injury and Inflammation, Neoplasia, Genetics, Cardiovascular
Pathology, Respiratory Pathology, Renal Pathology, Gastrointestinal Pathology,
Hematopathology, Endocrine Pathology, Reproductive Pathology, Neuropathology,
Infectious Disease
Administration: Computer-Based (Shelf/Step Prep)
Passing Score: Varies by institution (typically 70%+)
SECTION 1: CELL INJURY, INFLAMMATION, AND TISSUE REPAIR
(Questions 1-25)
1. A 58-year-old man with a history of alcohol use disorder undergoes a liver
biopsy. Microscopic examination shows hepatocytes with swollen, pale cytoplasm
containing clumped material. Which mechanism best explains this finding?
a) Apoptosis
b) Caseous necrosis
c) Fat accumulation
d) Hydropic swelling
e) Glycogen deposition
,Rationale: Hydropic swelling results from failure of the Na+/K+ ATPase pump, causing
water influx into the cell. This is a hallmark of reversible cell injury. The swollen, pale
cytoplasm with clumped material is characteristic of cellular swelling. Alcoholism can
cause direct toxic injury to hepatocytes .
2. A 72-year-old woman suffered a myocardial infarction one week ago. Histologic
examination of the infarct shows macrophages with granular pink cytoplasm and
neutrophils at the border. Which process is occurring?
a) Coagulative necrosis with organization
b) Liquefactive necrosis
c) Caseous necrosis
d) Fibrinoid necrosis
e) Gangrenous necrosis
Rationale: Coagulative necrosis is the characteristic pattern of ischemic injury in solid
organs like the heart. Neutrophils peak at approximately 1 week post-infarction, and
macrophages are present to clear debris. The presence of both cell types indicates the
process of organization .
3. A 35-year-old man sustains a rusty nail puncture wound to his foot. Within 24
hours, the foot becomes red, hot, and swollen. What is the primary cause of the
heat and redness observed?
a) Release of histamine from mast cells
b) Neutrophil chemotaxis
c) Vasodilation caused by inflammatory mediators
d) Tissue necrosis
e) Complement activation
Rationale: The heat (calor) and redness (rubor) are cardinal signs of inflammation caused
by vasodilation. Histamine, prostaglandins, and bradykinin are inflammatory mediators
that induce vasodilation, leading to increased blood flow. This is a classic acute
inflammatory response to a foreign body/infection .
4. Which of the following best describes the primary pathological finding in
Alzheimer disease?
,a) Lewy bodies in the substantia nigra
b) Neurofibrillary tangles and amyloid-beta plaques
c) Neuronal loss in the caudate nucleus
d) Demyelination of the optic nerve
e) Prion protein accumulation
Rationale: The primary pathological findings in Alzheimer disease are neurofibrillary
tangles (hyperphosphorylated tau protein inside neurons) and amyloid-beta plaques
(extracellular deposits). These are required for a definitive pathological diagnosis. Lewy
bodies are seen in Parkinson disease, and caudate loss is typical of Huntington disease .
5. A 22-year-old male presents with fever, sore throat, and fatigue. A complete
blood count reveals atypical lymphocytes with basophilic cytoplasm that appear
indented by red blood cells. What is the most likely cause?
a) HIV
b) Cytomegalovirus
c) Epstein-Barr virus
d) Streptococcus pyogenes
e) Toxoplasmosis
Rationale: The presence of atypical lymphocytes (Downey cells) with basophilic cytoplasm
that is indented by red blood cells is characteristic of infectious mononucleosis caused by
Epstein-Barr virus (EBV). These cells are reactive CD8+ T cells .
6. Which type of hypersensitivity reaction is associated with contact dermatitis?
a) Type I
b) Type II
c) Type III
d) Type IV
e) Type V
Rationale: Contact dermatitis is a Type IV (delayed-type) hypersensitivity reaction
mediated by T cells. Sensitized T cells release cytokines that attract macrophages, causing
an inflammatory response. This reaction typically takes 48-72 hours to develop after
exposure to the allergen .
, 7. A 60-year-old woman with atrial fibrillation presents with sudden abdominal
pain and bloody diarrhea. She is found to have a thrombus in the superior
mesenteric artery. What type of infarct is most likely to occur in the intestine?
a) White (anemic) infarct
b) Red (hemorrhagic) infarct
c) Liquefactive infarct
d) Caseous infarct
e) Gangrenous infarct
Rationale: The intestine is a loose tissue with dual blood supply (collateral circulation).
When infarction occurs, hemorrhage into the necrotic tissue creates a red (hemorrhagic)
infarct. White infarcts occur in solid organs with end-artery supply .
8. A 40-year-old woman underwent a mastectomy for breast cancer. One year
later, she develops swelling of the ipsilateral arm. Histology of subcutaneous
tissue shows dilated lymphatic channels and fibrosis. What is the most likely
mechanism?
a) Tumor compression of lymphatics
b) Radiation-induced fibrosis
c) Surgical lymphatic obstruction
d) Lymphedema due to filariasis
e) Venous thrombosis
Rationale: Axillary lymph node dissection for breast cancer can cause surgical lymphatic
obstruction, leading to chronic lymphedema. The characteristic histologic findings are
dilated lymphatic channels and fibrosis of subcutaneous tissue .
9. Which type of pneumonia is most commonly caused by Streptococcus
pneumoniae?
a) Viral pneumonia
b) Atypical pneumonia
c) Community-acquired pneumonia
d) Hospital-acquired pneumonia
e) Aspiration pneumonia
Rationale: Streptococcus pneumoniae is the most common cause of community-acquired
pneumonia. It typically causes a lobar pneumonia with productive cough, fever, and
pleuritic chest pain .
Rationales
EXAM INSTRUCTIONS
Exam: NBME Pathology Final Exam 2026–2027
Format: Multiple Choice, Clinical Vignettes
Content Areas: Cell Injury and Inflammation, Neoplasia, Genetics, Cardiovascular
Pathology, Respiratory Pathology, Renal Pathology, Gastrointestinal Pathology,
Hematopathology, Endocrine Pathology, Reproductive Pathology, Neuropathology,
Infectious Disease
Administration: Computer-Based (Shelf/Step Prep)
Passing Score: Varies by institution (typically 70%+)
SECTION 1: CELL INJURY, INFLAMMATION, AND TISSUE REPAIR
(Questions 1-25)
1. A 58-year-old man with a history of alcohol use disorder undergoes a liver
biopsy. Microscopic examination shows hepatocytes with swollen, pale cytoplasm
containing clumped material. Which mechanism best explains this finding?
a) Apoptosis
b) Caseous necrosis
c) Fat accumulation
d) Hydropic swelling
e) Glycogen deposition
,Rationale: Hydropic swelling results from failure of the Na+/K+ ATPase pump, causing
water influx into the cell. This is a hallmark of reversible cell injury. The swollen, pale
cytoplasm with clumped material is characteristic of cellular swelling. Alcoholism can
cause direct toxic injury to hepatocytes .
2. A 72-year-old woman suffered a myocardial infarction one week ago. Histologic
examination of the infarct shows macrophages with granular pink cytoplasm and
neutrophils at the border. Which process is occurring?
a) Coagulative necrosis with organization
b) Liquefactive necrosis
c) Caseous necrosis
d) Fibrinoid necrosis
e) Gangrenous necrosis
Rationale: Coagulative necrosis is the characteristic pattern of ischemic injury in solid
organs like the heart. Neutrophils peak at approximately 1 week post-infarction, and
macrophages are present to clear debris. The presence of both cell types indicates the
process of organization .
3. A 35-year-old man sustains a rusty nail puncture wound to his foot. Within 24
hours, the foot becomes red, hot, and swollen. What is the primary cause of the
heat and redness observed?
a) Release of histamine from mast cells
b) Neutrophil chemotaxis
c) Vasodilation caused by inflammatory mediators
d) Tissue necrosis
e) Complement activation
Rationale: The heat (calor) and redness (rubor) are cardinal signs of inflammation caused
by vasodilation. Histamine, prostaglandins, and bradykinin are inflammatory mediators
that induce vasodilation, leading to increased blood flow. This is a classic acute
inflammatory response to a foreign body/infection .
4. Which of the following best describes the primary pathological finding in
Alzheimer disease?
,a) Lewy bodies in the substantia nigra
b) Neurofibrillary tangles and amyloid-beta plaques
c) Neuronal loss in the caudate nucleus
d) Demyelination of the optic nerve
e) Prion protein accumulation
Rationale: The primary pathological findings in Alzheimer disease are neurofibrillary
tangles (hyperphosphorylated tau protein inside neurons) and amyloid-beta plaques
(extracellular deposits). These are required for a definitive pathological diagnosis. Lewy
bodies are seen in Parkinson disease, and caudate loss is typical of Huntington disease .
5. A 22-year-old male presents with fever, sore throat, and fatigue. A complete
blood count reveals atypical lymphocytes with basophilic cytoplasm that appear
indented by red blood cells. What is the most likely cause?
a) HIV
b) Cytomegalovirus
c) Epstein-Barr virus
d) Streptococcus pyogenes
e) Toxoplasmosis
Rationale: The presence of atypical lymphocytes (Downey cells) with basophilic cytoplasm
that is indented by red blood cells is characteristic of infectious mononucleosis caused by
Epstein-Barr virus (EBV). These cells are reactive CD8+ T cells .
6. Which type of hypersensitivity reaction is associated with contact dermatitis?
a) Type I
b) Type II
c) Type III
d) Type IV
e) Type V
Rationale: Contact dermatitis is a Type IV (delayed-type) hypersensitivity reaction
mediated by T cells. Sensitized T cells release cytokines that attract macrophages, causing
an inflammatory response. This reaction typically takes 48-72 hours to develop after
exposure to the allergen .
, 7. A 60-year-old woman with atrial fibrillation presents with sudden abdominal
pain and bloody diarrhea. She is found to have a thrombus in the superior
mesenteric artery. What type of infarct is most likely to occur in the intestine?
a) White (anemic) infarct
b) Red (hemorrhagic) infarct
c) Liquefactive infarct
d) Caseous infarct
e) Gangrenous infarct
Rationale: The intestine is a loose tissue with dual blood supply (collateral circulation).
When infarction occurs, hemorrhage into the necrotic tissue creates a red (hemorrhagic)
infarct. White infarcts occur in solid organs with end-artery supply .
8. A 40-year-old woman underwent a mastectomy for breast cancer. One year
later, she develops swelling of the ipsilateral arm. Histology of subcutaneous
tissue shows dilated lymphatic channels and fibrosis. What is the most likely
mechanism?
a) Tumor compression of lymphatics
b) Radiation-induced fibrosis
c) Surgical lymphatic obstruction
d) Lymphedema due to filariasis
e) Venous thrombosis
Rationale: Axillary lymph node dissection for breast cancer can cause surgical lymphatic
obstruction, leading to chronic lymphedema. The characteristic histologic findings are
dilated lymphatic channels and fibrosis of subcutaneous tissue .
9. Which type of pneumonia is most commonly caused by Streptococcus
pneumoniae?
a) Viral pneumonia
b) Atypical pneumonia
c) Community-acquired pneumonia
d) Hospital-acquired pneumonia
e) Aspiration pneumonia
Rationale: Streptococcus pneumoniae is the most common cause of community-acquired
pneumonia. It typically causes a lobar pneumonia with productive cough, fever, and
pleuritic chest pain .
