Master the Boards USMLE Step 2CK -
Hematology - Questions
A 73-year-old man comes to the office with fatigue that has become progressively
worse over the last several months. He is also short of breath when he walks up one
flight of stairs. He drinks 4 vodka martinis a day. He complains of numbness and tingling
in his feet. On physical examination he has decreased sensation of his feet. His
hematocrit is 28% and his MCV is 114 fL (elevated). What is the most appropriate next
step in management?
A. Vitamin B12 level
B. Folate level
C. Peripheral blood smear
D. Schilling test
E. Methylmalonic acid level - Answer: C. Although a macrocytic anemia could be from
B12 or folate deficiency, direct alcohol effect on the bone marrow, or liver disease, the
first step is a peripheral smear. This is to detect hypersegmented neutrophils. Once
hypersegmented neutrophils are seen, then you would get B12 and folate levels.
A 73-year-old woman comes with decreased position and vibratory sensation of the
lower extremities, a hematocrit of 28%, MCV of 114 fL, and hypersegmented
neutrophils. Her B12 level is decreased, but near the borderline of normal. What is the
most appropriate next step in the management of this patient?
A. Methylmalonic acid level
B. Anti-intrinsic factor antibodies
C. Anti-parietal cell antibodies
D. Schillings test
E. Folate level
F. Homocysteine level - Answer: A. USMLE Step 2 CK frequently tests the fact that
while both B12 and folate deficiency increase homocysteine levels, only B12 is
associated with an increased MMA. The B12 level can be normal in as many as a third
of patients with B12 deficiency because the carrier protein, transcobalamin, is an acute
phase reactant and can be elevated from many forms of stress such as infection,
cancer, or trauma. When the story suggests B12 deficiency and the B12 level is
equivocal, use an increased MMA level to confirm the diagnosis of vitamin B12
deficiency.
Which of the following is a complication of B12 or folate replacement?
A. Seizures
B. Hemolysis
C. Hypokalemia
D. Hyperkalemia
E. Diarrhea - Answer: C. Extremely rapid cell production in the bone marrow causes
hypokalemia. There is no other condition in which cells are generated so rapidly that
Hematology - Questions
A 73-year-old man comes to the office with fatigue that has become progressively
worse over the last several months. He is also short of breath when he walks up one
flight of stairs. He drinks 4 vodka martinis a day. He complains of numbness and tingling
in his feet. On physical examination he has decreased sensation of his feet. His
hematocrit is 28% and his MCV is 114 fL (elevated). What is the most appropriate next
step in management?
A. Vitamin B12 level
B. Folate level
C. Peripheral blood smear
D. Schilling test
E. Methylmalonic acid level - Answer: C. Although a macrocytic anemia could be from
B12 or folate deficiency, direct alcohol effect on the bone marrow, or liver disease, the
first step is a peripheral smear. This is to detect hypersegmented neutrophils. Once
hypersegmented neutrophils are seen, then you would get B12 and folate levels.
A 73-year-old woman comes with decreased position and vibratory sensation of the
lower extremities, a hematocrit of 28%, MCV of 114 fL, and hypersegmented
neutrophils. Her B12 level is decreased, but near the borderline of normal. What is the
most appropriate next step in the management of this patient?
A. Methylmalonic acid level
B. Anti-intrinsic factor antibodies
C. Anti-parietal cell antibodies
D. Schillings test
E. Folate level
F. Homocysteine level - Answer: A. USMLE Step 2 CK frequently tests the fact that
while both B12 and folate deficiency increase homocysteine levels, only B12 is
associated with an increased MMA. The B12 level can be normal in as many as a third
of patients with B12 deficiency because the carrier protein, transcobalamin, is an acute
phase reactant and can be elevated from many forms of stress such as infection,
cancer, or trauma. When the story suggests B12 deficiency and the B12 level is
equivocal, use an increased MMA level to confirm the diagnosis of vitamin B12
deficiency.
Which of the following is a complication of B12 or folate replacement?
A. Seizures
B. Hemolysis
C. Hypokalemia
D. Hyperkalemia
E. Diarrhea - Answer: C. Extremely rapid cell production in the bone marrow causes
hypokalemia. There is no other condition in which cells are generated so rapidly that
