USMLE Step 1 Pathology – High-Yield Mastery & Exam
Recap (Peak April–June Window)
A 62-year-old man with long-standing hypertension presents with progressive left ventricular
hypertrophy. Chronic pressure overload has led to increased myocardial wall thickness without chamber
dilation. Which of the following cellular adaptations best explains this morphologic change?
A. Hyperplasia
B. Hypertrophy
C. Metaplasia
D. Dysplasia
E. Aplasia
Correct Answer: B. Hypertrophy
Rationale:
Cardiac myocytes are terminally differentiated cells incapable of mitotic division. Chronic pressure
overload (e.g., hypertension) results in increased cell size due to synthesis of additional contractile
proteins. This is hypertrophy, not hyperplasia (increase in cell number).
2.
A 24-year-old woman experiences heavy menstrual bleeding and develops iron deficiency anemia. Bone
marrow biopsy shows increased erythropoietic precursors. Which adaptive response explains this
finding?
A. Hypertrophy
B. Metaplasia
C. Hyperplasia
D. Dysplasia
E. Atrophy
Correct Answer: C. Hyperplasia
Rationale:
Hyperplasia refers to increased cell number in response to physiologic or pathologic stimulation.
Increased erythropoietin stimulates marrow progenitors, causing compensatory hyperplasia.
3.
,A 58-year-old chronic smoker undergoes bronchoscopy. Histologic examination reveals replacement of
ciliated columnar epithelium with stratified squamous epithelium. Which process has occurred?
A. Dysplasia
B. Metaplasia
C. Hyperplasia
D. Anaplasia
E. Neoplasia
Correct Answer: B. Metaplasia
Rationale:
Metaplasia is a reversible substitution of one differentiated cell type for another better suited to stress.
Smoking induces squamous metaplasia in bronchial epithelium.
4.
A 70-year-old man develops a myocardial infarction due to occlusion of the left anterior descending
artery. Within 6 hours, histology shows eosinophilic cytoplasm and loss of nuclei. Which type of necrosis
is most characteristic?
A. Liquefactive
B. Caseous
C. Fat necrosis
D. Coagulative necrosis
E. Fibrinoid necrosis
Correct Answer: D. Coagulative necrosis
Rationale:
Ischemic injury in solid organs (except brain) produces coagulative necrosis characterized by preserved
architecture with protein denaturation.
5.
A patient with bacterial meningitis develops brain tissue destruction characterized by enzymatic
digestion and cavity formation. Which type of necrosis is present?
A. Coagulative
B. Liquefactive necrosis
C. Caseous
, D. Fat
E. Gangrenous
Correct Answer: B. Liquefactive necrosis
Rationale:
Liquefactive necrosis occurs in brain infarcts and abscesses due to enzymatic digestion by neutrophils
and microglia.
6.
A 45-year-old man with tuberculosis has granulomatous inflammation in the lung. Histology reveals
central amorphous debris with a “cheese-like” appearance. This is characteristic of:
A. Liquefactive necrosis
B. Coagulative necrosis
C. Caseous necrosis
D. Fat necrosis
E. Fibrinoid necrosis
Correct Answer: C. Caseous necrosis
Rationale:
Caseous necrosis is seen in tuberculosis and some fungal infections, combining features of coagulative
and liquefactive necrosis.
7.
Which of the following is the earliest morphologic change seen in reversible cell injury due to hypoxia?
A. Nuclear fragmentation
B. Membrane rupture
C. Cellular swelling
D. Lysosomal rupture
E. DNA degradation
Correct Answer: C. Cellular swelling
Rationale:
ATP depletion leads to failure of Na⁺/K⁺ pumps, causing intracellular sodium and water accumulation →
cellular swelling (hydropic change).
Recap (Peak April–June Window)
A 62-year-old man with long-standing hypertension presents with progressive left ventricular
hypertrophy. Chronic pressure overload has led to increased myocardial wall thickness without chamber
dilation. Which of the following cellular adaptations best explains this morphologic change?
A. Hyperplasia
B. Hypertrophy
C. Metaplasia
D. Dysplasia
E. Aplasia
Correct Answer: B. Hypertrophy
Rationale:
Cardiac myocytes are terminally differentiated cells incapable of mitotic division. Chronic pressure
overload (e.g., hypertension) results in increased cell size due to synthesis of additional contractile
proteins. This is hypertrophy, not hyperplasia (increase in cell number).
2.
A 24-year-old woman experiences heavy menstrual bleeding and develops iron deficiency anemia. Bone
marrow biopsy shows increased erythropoietic precursors. Which adaptive response explains this
finding?
A. Hypertrophy
B. Metaplasia
C. Hyperplasia
D. Dysplasia
E. Atrophy
Correct Answer: C. Hyperplasia
Rationale:
Hyperplasia refers to increased cell number in response to physiologic or pathologic stimulation.
Increased erythropoietin stimulates marrow progenitors, causing compensatory hyperplasia.
3.
,A 58-year-old chronic smoker undergoes bronchoscopy. Histologic examination reveals replacement of
ciliated columnar epithelium with stratified squamous epithelium. Which process has occurred?
A. Dysplasia
B. Metaplasia
C. Hyperplasia
D. Anaplasia
E. Neoplasia
Correct Answer: B. Metaplasia
Rationale:
Metaplasia is a reversible substitution of one differentiated cell type for another better suited to stress.
Smoking induces squamous metaplasia in bronchial epithelium.
4.
A 70-year-old man develops a myocardial infarction due to occlusion of the left anterior descending
artery. Within 6 hours, histology shows eosinophilic cytoplasm and loss of nuclei. Which type of necrosis
is most characteristic?
A. Liquefactive
B. Caseous
C. Fat necrosis
D. Coagulative necrosis
E. Fibrinoid necrosis
Correct Answer: D. Coagulative necrosis
Rationale:
Ischemic injury in solid organs (except brain) produces coagulative necrosis characterized by preserved
architecture with protein denaturation.
5.
A patient with bacterial meningitis develops brain tissue destruction characterized by enzymatic
digestion and cavity formation. Which type of necrosis is present?
A. Coagulative
B. Liquefactive necrosis
C. Caseous
, D. Fat
E. Gangrenous
Correct Answer: B. Liquefactive necrosis
Rationale:
Liquefactive necrosis occurs in brain infarcts and abscesses due to enzymatic digestion by neutrophils
and microglia.
6.
A 45-year-old man with tuberculosis has granulomatous inflammation in the lung. Histology reveals
central amorphous debris with a “cheese-like” appearance. This is characteristic of:
A. Liquefactive necrosis
B. Coagulative necrosis
C. Caseous necrosis
D. Fat necrosis
E. Fibrinoid necrosis
Correct Answer: C. Caseous necrosis
Rationale:
Caseous necrosis is seen in tuberculosis and some fungal infections, combining features of coagulative
and liquefactive necrosis.
7.
Which of the following is the earliest morphologic change seen in reversible cell injury due to hypoxia?
A. Nuclear fragmentation
B. Membrane rupture
C. Cellular swelling
D. Lysosomal rupture
E. DNA degradation
Correct Answer: C. Cellular swelling
Rationale:
ATP depletion leads to failure of Na⁺/K⁺ pumps, causing intracellular sodium and water accumulation →
cellular swelling (hydropic change).
