MLPAO Hematology and Coagulation Case Studies 1 — Questions and Answers
Question 1: A patient has hemoglobin 85 g/L, MCV 65 fL, RDW 18%, and serum ferritin 5 µg/L. What is the most likely diagnosis?
- Beta-thalassemia trait
- Iron deficiency anemia (Correct answer)
- Anemia of chronic disease
- Sideroblastic anemia
Correct answer: Iron deficiency anemia
The combination of low hemoglobin, microcytosis (MCV 65 fL), elevated RDW (anisocytosis), and very low ferritin (5 µg/L) is classic for iron deficiency anemia. Beta-thalassemia trait typically has a normal RDW and normal ferritin. The low ferritin is the most specific finding for iron deficiency.
Question 2: A 70-year-old patient has WBC 85 × 10⁹/L with 90% mature lymphocytes and numerous smudge cells. What is the most likely diagnosis?
- Acute lymphoblastic leukemia
- Chronic lymphocytic leukemia (Correct answer)
- Infectious mononucleosis
- Chronic myeloid leukemia
Correct answer: Chronic lymphocytic leukemia
The clinical picture of an elderly patient with markedly elevated WBC, predominance of mature lymphocytes, and smudge cells (basket cells) is classic for chronic lymphocytic leukemia (CLL). Smudge cells result from the fragility of CLL lymphocytes during smear preparation. Immunophenotyping would show CD5+, CD19+, CD23+ B cells.
Question 3: A patient on warfarin has an INR of 8.5 with no active bleeding. What is the recommended management?
- Continue warfarin at the same dose
- Hold warfarin and administer oral vitamin K (Correct answer)
- Give fresh frozen plasma immediately
- Increase warfarin dose
Correct answer: Hold warfarin and administer oral vitamin K
For an INR >4.5-10 without significant bleeding, the recommended approach is to hold warfarin and administer low-dose oral vitamin K (1-2.5 mg). This will lower the INR within 24-48 hours. Fresh frozen plasma or prothrombin complex concentrate is reserved for active life-threatening bleeding.
Question 4: A patient has prolonged PT and aPTT that both correct on mixing with normal plasma. Which condition is most likely?
- Lupus anticoagulant
- Multiple factor deficiency (such as liver disease or DIC) (Correct answer)
- Factor VIII inhibitor
- Antiphospholipid syndrome
Correct answer: Multiple factor deficiency (such as liver disease or DIC)
When both PT and aPTT are prolonged and correct on mixing, it indicates deficiency of one or more coagulation factors in both pathways. Common causes include liver disease (decreased synthesis), DIC (consumption), and vitamin K deficiency. Inhibitors would not correct on mixing study.
Question 5: A newborn has hemoglobin F 90%, hemoglobin A 0%, and hemoglobin A2 2%. What is the most likely diagnosis?
- Normal newborn hemoglobin pattern
- Beta-thalassemia major
- Sickle cell disease
- Either normal newborn or beta-thalassemia major — requires follow-up (Correct answer)
Correct answer: Either normal newborn or beta-thalassemia major — requires follow-up
At birth, hemoglobin F normally comprises 60-90% of total hemoglobin, and HbA gradually increases. The absence of HbA could be normal in early neonatal life or could indicate beta-thalassemia major. Follow-up hemoglobin electrophoresis at 6-12 months is essential when HbF to HbA switching should be complete.
Question 6: A patient has platelet count 15 × 10⁹/L, normal PT/aPTT, and large platelets on the smear. Anti-platelet antibodies are positive. What is the most likely diagnosis?
- Thrombotic thrombocytopenic purpura
- Immune thrombocytopenia (ITP) (Correct answer)
- Disseminated intravascular coagulation
- Aplastic anemia
Correct answer: Immune thrombocytopenia (ITP)
The combination of severe isolated thrombocytopenia, normal coagulation studies, large platelets (indicating increased production), and positive anti-platelet antibodies is classic for immune thrombocytopenia (ITP). In ITP, antibodies target platelet surface glycoproteins, leading to accelerated platelet destruction by the spleen.
MLPAO Hematology and Coagulation Case Studies 1
A patient has hemoglobin 85 g/L, MCV 65 fL, RDW 18%, and serum ferritin 5 µg/L.
What is the most likely diagnosis?