ADVANCED PATHOPHYSIOLOGY
1. A 62-year-old male presents with fatigue, weight loss, and a persistent
cough. Imaging reveals a mass in the right lung. Biopsy shows malignant cells
producing parathyroid hormone-related peptide (PTHrP). Which
paraneoplastic syndrome is most likely present?
A. SIADH
B. Hypercalcemia
C. Cushing syndrome
D. Lambert-Eaton syndrome
Answer: B
Rationale: PTHrP secretion causes increased bone resorption and hypercalcemia.
SIADH is associated with ectopic ADH secretion (often small cell lung cancer).
Cushing syndrome results from ectopic ACTH production. Lambert-Eaton is
associated with neuromuscular weakness due to autoantibodies affecting
presynaptic calcium channels.
2. A patient has chronic GERD. Which cellular adaptation is most likely to
occur in the lower esophagus?
A. Dysplasia
B. Metaplasia
C. Hypertrophy
D. Hyperplasia
Answer: B
Rationale: Chronic acid exposure leads to replacement of squamous epithelium
with columnar epithelium (Barrett esophagus), a classic example of metaplasia.
3. A 35-year-old woman presents with sudden onset of shortness of breath and
,pleuritic chest pain. She has a history of deep vein thrombosis. Which
pathophysiologic mechanism best explains her symptoms?
A. Bronchoconstriction due to mast cell activation
B. Alveolar collapse due to surfactant deficiency
C. Pulmonary vascular obstruction leading to V/Q mismatch
D. Infection causing inflammation of the pleura
Answer: C
Rationale: Pulmonary embolism causes obstruction of pulmonary arteries,
resulting in impaired perfusion of ventilated alveoli, causing a ventilation-
perfusion (V/Q) mismatch and hypoxemia.
4. A patient with untreated type 1 diabetes presents with nausea, abdominal
pain, fruity breath, and Kussmaul respirations. Which acid-base disturbance
is most likely?
A. Respiratory alkalosis
B. Metabolic alkalosis
C. Respiratory acidosis
D. Metabolic acidosis
Answer: D
Rationale: DKA causes increased ketone production, leading to metabolic
acidosis. Kussmaul respirations are a compensatory response.
5. A 48-year-old male presents with severe abdominal pain radiating to the
back, elevated serum amylase and lipase, and a history of alcohol abuse.
Which mechanism is responsible for his condition?
A. Autoimmune destruction of pancreatic beta cells
B. Activation of pancreatic enzymes within the pancreas
C. Obstruction of the common bile duct
D. Viral infection of pancreatic tissue
Answer: B
Rationale: Acute pancreatitis is caused by premature activation of pancreatic
enzymes, leading to autodigestion and inflammation.
,6. A patient develops sudden right-sided weakness and aphasia. CT scan
reveals an ischemic stroke in the left middle cerebral artery territory. Which
mechanism best explains the neurologic deficits?
A. Increased intracranial pressure
B. Ischemia leading to neuronal death
C. Demyelination of motor neurons
D. Autoimmune destruction of synapses
Answer: B
Rationale: Ischemic stroke causes decreased blood flow, leading to oxygen
deprivation, ATP depletion, and neuronal cell death.
7. A patient with chronic kidney disease develops anemia. Which mechanism
best explains the anemia?
A. Reduced erythropoietin production
B. Increased hemolysis
C. Iron overload
D. Increased platelet destruction
Answer: A
Rationale: Kidneys produce erythropoietin; chronic kidney disease reduces
erythropoietin, leading to decreased RBC production and anemia.
8. A 27-year-old woman presents with fatigue, cold intolerance, constipation,
and weight gain. Lab results show elevated TSH and low T4. What is the most
likely diagnosis?
A. Hyperthyroidism
B. Hypothyroidism
C. Cushing syndrome
D. Addison disease
Answer: B
Rationale: Elevated TSH with low T4 indicates primary hypothyroidism.
9. A patient presents with chronic inflammation and tissue remodeling in the
airways, leading to airflow obstruction and hyperresponsiveness. Which
, disease process is most consistent with these findings?
A. COPD
B. Asthma
C. Pulmonary fibrosis
D. Bronchiectasis
Answer: B
Rationale: Asthma is characterized by chronic airway inflammation,
hyperresponsiveness, and reversible airflow obstruction.
10. A 70-year-old male presents with bone pain and hypercalcemia. Lab
results show elevated alkaline phosphatase and elevated prostate-specific
antigen (PSA). What is the most likely cause of his symptoms?
A. Multiple myeloma
B. Osteoporosis
C. Metastatic prostate cancer to bone
D. Primary hyperparathyroidism
Answer: C
Rationale: Prostate cancer commonly metastasizes to bone, causing osteoblastic
lesions and elevated alkaline phosphatase, leading to bone pain and hypercalcemia.
11. A patient presents with fatigue, jaundice, and elevated AST and ALT. The
liver biopsy shows lymphocytic infiltration and autoimmune markers. What is
the most likely diagnosis?
A. Alcoholic hepatitis
B. Autoimmune hepatitis
C. Nonalcoholic fatty liver disease
D. Viral hepatitis
Answer: B
Rationale: Autoimmune hepatitis presents with lymphocytic infiltration and
autoimmune markers.
12. A patient has chronic hypertension leading to left ventricular
hypertrophy. Which adaptation is most responsible for the hypertrophy?