Massachusetts United States Medical
Licensing Examination Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
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1. A 24-year-old man presents with progressive muscle weakness
beginning in the shoulders and hips. He has difficulty climbing stairs
and rising from a seated position. Laboratory studies show elevated
creatine kinase. Muscle biopsy reveals inflammatory infiltrates
predominantly composed of CD8+ T cells attacking muscle fibers
expressing MHC class I. Which diagnosis best fits this presentation?
A. Dermatomyositis
B. Inclusion body myositis
C. Polymyositis
D. Myasthenia gravis
Rationale: Polymyositis is characterized by proximal muscle
weakness, elevated CK, and CD8+ T-cell–mediated destruction of
muscle fibers expressing MHC class I.
2. A newborn develops jaundice and anemia shortly after birth. The
mother is Rh-negative and did not receive prenatal care. The infant’s
red blood cells are coated with IgG antibodies. Which mechanism best
explains the hemolysis?
A. Complement-mediated lysis of maternal RBCs
B. Maternal IgG crossing the placenta and opsonizing fetal RBCs
C. Fetal IgM attacking maternal RBCs
D. T-cell–mediated destruction of fetal RBCs
, Rationale: In hemolytic disease of the newborn, maternal anti-Rh IgG
crosses the placenta and targets fetal RBCs for destruction.
3. A 55-year-old man with long-standing hypertension develops left
ventricular hypertrophy. Which cellular adaptation is primarily
responsible for the increased myocardial mass?
A. Hyperplasia of cardiomyocytes
B. Increased cell number via mitosis
C. Hypertrophy due to increased protein synthesis
D. Metaplasia of cardiac muscle cells
Rationale: Adult cardiomyocytes cannot divide; increased workload
leads to hypertrophy via increased protein synthesis and cell size.
4. A patient with chronic alcoholism presents with confusion, ataxia, and
ophthalmoplegia. Which vitamin deficiency is the most likely cause?
A. Vitamin B6
B. Vitamin B1 (thiamine)
C. Vitamin B12
D. Niacin
Rationale: The triad of Wernicke encephalopathy is caused by
thiamine deficiency in chronic alcohol use.
5. A 35-year-old woman has heat intolerance, weight loss, and
palpitations. Her TSH is low and free T4 is elevated. Which antibody is
most likely responsible?
A. Anti-thyroid peroxidase
B. Anti-thyroglobulin
C. TSH receptor–stimulating antibodies
D. Anti-insulin receptor antibodies
Rationale: Graves disease is caused by IgG antibodies that stimulate
the TSH receptor, increasing thyroid hormone production.
6. A patient has difficulty adducting the eye and experiences diplopia
when looking laterally. Which cranial nerve is most likely affected?
A. CN II
B. CN III
C. CN VI
D. CN IV
, Rationale: The abducens nerve (CN VI) innervates the lateral rectus
muscle, responsible for abduction of the eye.
7. A mutation causes decreased activity of phenylalanine hydroxylase.
Which compound will accumulate?
A. Tyrosine
B. Phenylalanine
C. Dopamine
D. Melanin
Rationale: Phenylketonuria results from phenylalanine hydroxylase
deficiency, leading to accumulation of phenylalanine.
8. A 60-year-old man presents with painless hematuria and weight loss.
Imaging shows a renal mass. Which genetic alteration is most
associated with clear cell renal carcinoma?
A. p53 mutation
B. VHL gene inactivation
C. APC mutation
D. RB gene deletion
Rationale: Clear cell renal carcinoma is strongly associated with
inactivation of the VHL tumor suppressor gene.
9. A patient has low calcium levels due to parathyroid gland removal.
Which ECG change is expected?
A. Shortened QT interval
B. Prolonged QT interval
C. ST-segment elevation
D. T-wave inversion
Rationale: Hypocalcemia prolongs the QT interval by lengthening the
ST segment.
10. A 5-year-old child has recurrent infections and absent thymic
shadow on chest X-ray. Which condition is most likely?
A. Wiskott-Aldrich syndrome
B. DiGeorge syndrome
C. Severe combined immunodeficiency
D. Bruton's agammaglobulinemia
Rationale: DiGeorge syndrome involves thymic aplasia from 22q11
deletion, leading to T-cell deficiency.
Licensing Examination Questions And
Correct Answers (Verified Answers) Plus
Rationale 2026 Q&A| Instant Download
1. A 24-year-old man presents with progressive muscle weakness
beginning in the shoulders and hips. He has difficulty climbing stairs
and rising from a seated position. Laboratory studies show elevated
creatine kinase. Muscle biopsy reveals inflammatory infiltrates
predominantly composed of CD8+ T cells attacking muscle fibers
expressing MHC class I. Which diagnosis best fits this presentation?
A. Dermatomyositis
B. Inclusion body myositis
C. Polymyositis
D. Myasthenia gravis
Rationale: Polymyositis is characterized by proximal muscle
weakness, elevated CK, and CD8+ T-cell–mediated destruction of
muscle fibers expressing MHC class I.
2. A newborn develops jaundice and anemia shortly after birth. The
mother is Rh-negative and did not receive prenatal care. The infant’s
red blood cells are coated with IgG antibodies. Which mechanism best
explains the hemolysis?
A. Complement-mediated lysis of maternal RBCs
B. Maternal IgG crossing the placenta and opsonizing fetal RBCs
C. Fetal IgM attacking maternal RBCs
D. T-cell–mediated destruction of fetal RBCs
, Rationale: In hemolytic disease of the newborn, maternal anti-Rh IgG
crosses the placenta and targets fetal RBCs for destruction.
3. A 55-year-old man with long-standing hypertension develops left
ventricular hypertrophy. Which cellular adaptation is primarily
responsible for the increased myocardial mass?
A. Hyperplasia of cardiomyocytes
B. Increased cell number via mitosis
C. Hypertrophy due to increased protein synthesis
D. Metaplasia of cardiac muscle cells
Rationale: Adult cardiomyocytes cannot divide; increased workload
leads to hypertrophy via increased protein synthesis and cell size.
4. A patient with chronic alcoholism presents with confusion, ataxia, and
ophthalmoplegia. Which vitamin deficiency is the most likely cause?
A. Vitamin B6
B. Vitamin B1 (thiamine)
C. Vitamin B12
D. Niacin
Rationale: The triad of Wernicke encephalopathy is caused by
thiamine deficiency in chronic alcohol use.
5. A 35-year-old woman has heat intolerance, weight loss, and
palpitations. Her TSH is low and free T4 is elevated. Which antibody is
most likely responsible?
A. Anti-thyroid peroxidase
B. Anti-thyroglobulin
C. TSH receptor–stimulating antibodies
D. Anti-insulin receptor antibodies
Rationale: Graves disease is caused by IgG antibodies that stimulate
the TSH receptor, increasing thyroid hormone production.
6. A patient has difficulty adducting the eye and experiences diplopia
when looking laterally. Which cranial nerve is most likely affected?
A. CN II
B. CN III
C. CN VI
D. CN IV
, Rationale: The abducens nerve (CN VI) innervates the lateral rectus
muscle, responsible for abduction of the eye.
7. A mutation causes decreased activity of phenylalanine hydroxylase.
Which compound will accumulate?
A. Tyrosine
B. Phenylalanine
C. Dopamine
D. Melanin
Rationale: Phenylketonuria results from phenylalanine hydroxylase
deficiency, leading to accumulation of phenylalanine.
8. A 60-year-old man presents with painless hematuria and weight loss.
Imaging shows a renal mass. Which genetic alteration is most
associated with clear cell renal carcinoma?
A. p53 mutation
B. VHL gene inactivation
C. APC mutation
D. RB gene deletion
Rationale: Clear cell renal carcinoma is strongly associated with
inactivation of the VHL tumor suppressor gene.
9. A patient has low calcium levels due to parathyroid gland removal.
Which ECG change is expected?
A. Shortened QT interval
B. Prolonged QT interval
C. ST-segment elevation
D. T-wave inversion
Rationale: Hypocalcemia prolongs the QT interval by lengthening the
ST segment.
10. A 5-year-old child has recurrent infections and absent thymic
shadow on chest X-ray. Which condition is most likely?
A. Wiskott-Aldrich syndrome
B. DiGeorge syndrome
C. Severe combined immunodeficiency
D. Bruton's agammaglobulinemia
Rationale: DiGeorge syndrome involves thymic aplasia from 22q11
deletion, leading to T-cell deficiency.
