HEMATOLOGY EXAM | 2026 UPDATE WITH
COMPLETE SOLUTIONS.
SECTION 1: ANEMIA – MICROCYTIC
1. A 45-year-old woman presents with fatigue, pallor, and heavy menstrual
bleeding. Laboratory findings: Hb 8.5 g/dL, MCV 72 fL, ferritin 8 ng/mL, serum
iron 25 μg/dL, and TIBC 450 μg/dL. What is the most likely diagnosis?
• A) Anemia of chronic disease
• B) Iron deficiency anemia
• C) Thalassemia trait
• D) Sideroblastic anemia
Correct Answer: B
*Rationale: Iron deficiency anemia is characterized by microcytic (low MCV),
hypochromic anemia with low ferritin (< 30 ng/mL), low serum iron, and elevated
TIBC. Heavy menstrual bleeding is a common cause in premenopausal women.
Ferritin is the most sensitive and specific test for iron deficiency.*
2. A 65-year-old man with a history of rheumatoid arthritis presents with
anemia. Laboratory findings: Hb 10.0 g/dL, MCV 78 fL, ferritin 120 ng/mL, serum
iron 40 μg/dL, and TIBC 200 μg/dL. What is the most likely diagnosis?
• A) Iron deficiency anemia
• B) Anemia of chronic disease
, • C) Thalassemia trait
• D) Sideroblastic anemia
Correct Answer: B
Rationale: Anemia of chronic disease (ACD) is characterized by normocytic or
mildly microcytic anemia, low serum iron, low TIBC, and normal or elevated
ferritin. The elevated ferritin with low iron and low TIBC indicates iron
sequestration due to inflammation.
3. A patient of Southeast Asian descent has microcytic anemia with a normal
ferritin level. Hemoglobin electrophoresis shows elevated HbA₂ (5.5%). What is
the most likely diagnosis?
• A) Iron deficiency anemia
• B) β-thalassemia trait
• C) α-thalassemia trait
• D) Sideroblastic anemia
Correct Answer: B
*Rationale: β-thalassemia trait (minor) is characterized by microcytic anemia with
a normal ferritin level and elevated HbA₂ (> 3.5%) on hemoglobin electrophoresis.
α-thalassemia trait typically has normal HbA₂. Iron deficiency has low ferritin.*
4. A 50-year-old woman with a history of gastric bypass surgery presents with
macrocytic anemia, peripheral neuropathy, and positive Romberg sign.
Laboratory findings: Hb 9.0 g/dL, MCV 110 fL, and elevated homocysteine. What
is the most likely diagnosis?
• A) Iron deficiency anemia
• B) Vitamin B12 deficiency
• C) Folate deficiency
, • D) Myelodysplastic syndrome
Correct Answer: B
Rationale: Vitamin B12 deficiency causes macrocytic anemia, subacute combined
degeneration of the spinal cord (peripheral neuropathy, positive Romberg sign).
Gastric bypass surgery reduces intrinsic factor production. Homocysteine and
methylmalonic acid (MMA) are elevated in B12 deficiency.
5. Which of the following laboratory findings distinguishes vitamin B12
deficiency from folate deficiency?
• A) Elevated homocysteine
• B) Elevated methylmalonic acid (MMA)
• C) Macrocytic anemia
• D) Elevated LDH
Correct Answer: B
*Rationale: Both B12 and folate deficiencies cause elevated homocysteine.
However, only B12 deficiency causes elevated methylmalonic acid (MMA),
because MMA is a byproduct of methylmalonyl-CoA metabolism, which requires
vitamin B12 as a cofactor.*
6. A patient with iron deficiency anemia is started on oral ferrous sulfate. Which
of the following indicates an appropriate response to therapy?
• A) Increased ferritin within 24 hours
• B) Reticulocytosis within 3-5 days
• C) Normalization of hemoglobin within 2 days
• D) Decreased TIBC within 1 week
, Correct Answer: B
*Rationale: Reticulocytosis is the earliest sign of response to iron therapy,
appearing within 3-5 days. Hemoglobin begins to rise in 1-2 weeks and normalizes
in 6-8 weeks. Ferritin rises later. TIBC normalizes with iron repletion.*
7. A patient with anemia is found to have hemoglobin of 9.0 g/dL, MCV of 115
fL, and normal B12 and folate levels. Bone marrow biopsy shows ringed
sideroblasts. What is the most likely diagnosis?
• A) Iron deficiency anemia
• B) Vitamin B12 deficiency
• C) Sideroblastic anemia
• D) Myelodysplastic syndrome
Correct Answer: C
Rationale: Sideroblastic anemia is characterized by macrocytic or normocytic
anemia with ringed sideroblasts on bone marrow biopsy. It can be congenital or
acquired (associated with myelodysplastic syndrome, alcohol, lead poisoning, or
isoniazid).
8. A 25-year-old African American woman presents with mild anemia (Hb 10.5
g/dL), MCV 70 fL, and normal ferritin. Hemoglobin electrophoresis shows HbS
60%, HbF 25%, and HbA2 15%. What is the most likely diagnosis?
• A) Sickle cell trait
• B) Sickle cell disease (HbSS)
• C) Sickle cell-β-thalassemia
• D) Sickle cell-α-thalassemia
Correct Answer: C
*Rationale: Sickle cell-β-thalassemia is characterized by HbS (50-70%), HbF (10-
COMPLETE SOLUTIONS.
SECTION 1: ANEMIA – MICROCYTIC
1. A 45-year-old woman presents with fatigue, pallor, and heavy menstrual
bleeding. Laboratory findings: Hb 8.5 g/dL, MCV 72 fL, ferritin 8 ng/mL, serum
iron 25 μg/dL, and TIBC 450 μg/dL. What is the most likely diagnosis?
• A) Anemia of chronic disease
• B) Iron deficiency anemia
• C) Thalassemia trait
• D) Sideroblastic anemia
Correct Answer: B
*Rationale: Iron deficiency anemia is characterized by microcytic (low MCV),
hypochromic anemia with low ferritin (< 30 ng/mL), low serum iron, and elevated
TIBC. Heavy menstrual bleeding is a common cause in premenopausal women.
Ferritin is the most sensitive and specific test for iron deficiency.*
2. A 65-year-old man with a history of rheumatoid arthritis presents with
anemia. Laboratory findings: Hb 10.0 g/dL, MCV 78 fL, ferritin 120 ng/mL, serum
iron 40 μg/dL, and TIBC 200 μg/dL. What is the most likely diagnosis?
• A) Iron deficiency anemia
• B) Anemia of chronic disease
, • C) Thalassemia trait
• D) Sideroblastic anemia
Correct Answer: B
Rationale: Anemia of chronic disease (ACD) is characterized by normocytic or
mildly microcytic anemia, low serum iron, low TIBC, and normal or elevated
ferritin. The elevated ferritin with low iron and low TIBC indicates iron
sequestration due to inflammation.
3. A patient of Southeast Asian descent has microcytic anemia with a normal
ferritin level. Hemoglobin electrophoresis shows elevated HbA₂ (5.5%). What is
the most likely diagnosis?
• A) Iron deficiency anemia
• B) β-thalassemia trait
• C) α-thalassemia trait
• D) Sideroblastic anemia
Correct Answer: B
*Rationale: β-thalassemia trait (minor) is characterized by microcytic anemia with
a normal ferritin level and elevated HbA₂ (> 3.5%) on hemoglobin electrophoresis.
α-thalassemia trait typically has normal HbA₂. Iron deficiency has low ferritin.*
4. A 50-year-old woman with a history of gastric bypass surgery presents with
macrocytic anemia, peripheral neuropathy, and positive Romberg sign.
Laboratory findings: Hb 9.0 g/dL, MCV 110 fL, and elevated homocysteine. What
is the most likely diagnosis?
• A) Iron deficiency anemia
• B) Vitamin B12 deficiency
• C) Folate deficiency
, • D) Myelodysplastic syndrome
Correct Answer: B
Rationale: Vitamin B12 deficiency causes macrocytic anemia, subacute combined
degeneration of the spinal cord (peripheral neuropathy, positive Romberg sign).
Gastric bypass surgery reduces intrinsic factor production. Homocysteine and
methylmalonic acid (MMA) are elevated in B12 deficiency.
5. Which of the following laboratory findings distinguishes vitamin B12
deficiency from folate deficiency?
• A) Elevated homocysteine
• B) Elevated methylmalonic acid (MMA)
• C) Macrocytic anemia
• D) Elevated LDH
Correct Answer: B
*Rationale: Both B12 and folate deficiencies cause elevated homocysteine.
However, only B12 deficiency causes elevated methylmalonic acid (MMA),
because MMA is a byproduct of methylmalonyl-CoA metabolism, which requires
vitamin B12 as a cofactor.*
6. A patient with iron deficiency anemia is started on oral ferrous sulfate. Which
of the following indicates an appropriate response to therapy?
• A) Increased ferritin within 24 hours
• B) Reticulocytosis within 3-5 days
• C) Normalization of hemoglobin within 2 days
• D) Decreased TIBC within 1 week
, Correct Answer: B
*Rationale: Reticulocytosis is the earliest sign of response to iron therapy,
appearing within 3-5 days. Hemoglobin begins to rise in 1-2 weeks and normalizes
in 6-8 weeks. Ferritin rises later. TIBC normalizes with iron repletion.*
7. A patient with anemia is found to have hemoglobin of 9.0 g/dL, MCV of 115
fL, and normal B12 and folate levels. Bone marrow biopsy shows ringed
sideroblasts. What is the most likely diagnosis?
• A) Iron deficiency anemia
• B) Vitamin B12 deficiency
• C) Sideroblastic anemia
• D) Myelodysplastic syndrome
Correct Answer: C
Rationale: Sideroblastic anemia is characterized by macrocytic or normocytic
anemia with ringed sideroblasts on bone marrow biopsy. It can be congenital or
acquired (associated with myelodysplastic syndrome, alcohol, lead poisoning, or
isoniazid).
8. A 25-year-old African American woman presents with mild anemia (Hb 10.5
g/dL), MCV 70 fL, and normal ferritin. Hemoglobin electrophoresis shows HbS
60%, HbF 25%, and HbA2 15%. What is the most likely diagnosis?
• A) Sickle cell trait
• B) Sickle cell disease (HbSS)
• C) Sickle cell-β-thalassemia
• D) Sickle cell-α-thalassemia
Correct Answer: C
*Rationale: Sickle cell-β-thalassemia is characterized by HbS (50-70%), HbF (10-
