Nokea
A 17-year-old patient is referred to you for a platelet count of 1,200,000/mm3. On history, she notes that she often has numbness and tingling in her hands and feet and has frequent epistaxis. She is otherwise well-appearing and has no recent infections. On her exam, you note splenomegaly. What do you expect to see on further evaluation?
- A. Elevated C-reactive protein
- B. Low ferritin
- C. A hypocellular bone marrow
- D. Low von Willebrand factor activity
Correct Answer: D
Rationale: The correct answer is D: Low von Willebrand factor activity. A platelet count of 1,200,000/mm3 suggests thrombocytosis, which can be seen in conditions like essential thrombocythemia. This condition is associated with low von Willebrand factor activity, leading to increased bleeding tendency despite high platelet counts. Numbness, tingling, epistaxis, and splenomegaly are common features of essential thrombocythemia. Elevated C-reactive protein is not typically associated with this condition. Low ferritin is more indicative of iron deficiency anemia, not thrombocytosis. A hypocellular bone marrow is not expected in essential thrombocythemia, as it is characterized by increased platelet production.
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A 13-year-old boy presents to the emergency department with complaints of headache and visual changes. History reveals progressive dyspnea on exertion, generalized fatigue, and increased bruising. His labs are significant for a WBC of 350,000/mcL, of which 80% are reported to be blasts and appear to be myeloblasts without the presence of Auer rods. His hemoglobin is 7.2 g/dL, and his platelets are 18,000/mcL. A CT scan of the head shows a small intracerebral hemorrhage. His coags are normal. Which of the following is the most appropriate therapy?
- A. Start induction chemotherapy.
- B. Perform emergent leukapheresis followed the next day by induction chemotherapy.
- C. Perform emergent leukapheresis plus hydroxyurea.
- D. Provide emergent cranial radiation plus hydroxyurea followed the next day by induction chemotherapy.
Correct Answer: C
Rationale: The most appropriate therapy in this scenario is emergent leukapheresis plus hydroxyurea (Choice C). Leukapheresis is needed to rapidly reduce the high white blood cell count, preventing further complications such as leukostasis and hyperviscosity syndrome. Hydroxyurea can help further control the rapid proliferation of blasts. Induction chemotherapy (Choice A) may lead to tumor lysis syndrome due to the high tumor burden. Performing leukapheresis alone without a subsequent therapy (Choice B) may not adequately address the underlying disease. Providing cranial radiation (Choice D) is not the initial management for acute myeloid leukemia.
During haemostasis, prostacyclin
- A. Cleaves prothrombin into thrombin
- B. Causes vasodilation
- C. Stimulates platelet aggregation
- D. Activates fibrinolysis
Correct Answer: B
Rationale: Prostacyclin is a vasodilator, which means it causes blood vessels to widen, leading to decreased blood pressure and increased blood flow. During haemostasis, this vasodilation helps in maintaining blood flow and preventing platelet aggregation in the damaged area. Option A is incorrect because prostacyclin does not cleave prothrombin into thrombin. Option C is incorrect as prostacyclin inhibits platelet aggregation. Option D is incorrect because prostacyclin does not directly activate fibrinolysis. In summary, the correct answer is B because prostacyclin's vasodilation function plays a crucial role in haemostasis by preventing excessive clot formation and maintaining blood flow.
The mean cell volume of the patient is 90 fl and the reticulocyte production index is low. Which of the following is the most possible cause of anemia in this patient?
- A. Thalassemia
- B. Vitamin B12 deficiency
- C. Aplastic anemia
- D. Sideroblastic anemia
Correct Answer: C
Rationale: Rationale: A low reticulocyte production index indicates decreased bone marrow response to anemia. Aplastic anemia is characterized by bone marrow failure leading to pancytopenia, causing anemia. Thalassemia results in microcytic anemia, not macrocytic. Vitamin B12 deficiency causes macrocytic anemia due to impaired DNA synthesis. Sideroblastic anemia leads to microcytic anemia due to defective heme synthesis. Therefore, the most likely cause of anemia in this patient with a low reticulocyte production index and normal mean cell volume is aplastic anemia.
Increase Fe & normal TIBC are found in:
- A. thalassemia major
- B. haemosidrosis
- C. rheumatoid arthritis
- D. dissiminated malignancy
Correct Answer: C
Rationale: The correct answer is C: rheumatoid arthritis. In rheumatoid arthritis, chronic inflammation can lead to anemia of chronic disease, causing increased levels of serum iron (Fe) due to decreased iron utilization and normal Total Iron Binding Capacity (TIBC). Thalassemia major (A) would show decreased TIBC due to iron overload. Haemosiderosis (B) would show increased Fe and TIBC due to iron overload. Disseminated malignancy (D) may show decreased Fe and TIBC due to anemia of chronic disease or other factors.
A patient shows prolonged prothrombin time and activated partial thromboplastin time. Blood test otherwise is normal. Which of the following is the most probably diagnosis for this patient's condition?
- A. Hemophilia A
- B. Thrombocytopenia
- C. Von Willebrand factor disease
- D. Vitamin K deficiency
Correct Answer: D
Rationale: The correct answer is D: Vitamin K deficiency. Prolonged prothrombin time and activated partial thromboplastin time indicate impaired blood clotting, which is characteristic of vitamin K deficiency. Vitamin K is essential for synthesizing clotting factors II, VII, IX, and X. Hemophilia A (choice A) is a genetic disorder resulting in deficiency of clotting factor VIII, not vitamin K-dependent factors. Thrombocytopenia (choice B) is a condition characterized by low platelet count, not affecting clotting factor synthesis. Von Willebrand factor disease (choice C) involves a deficiency or dysfunction of von Willebrand factor, not related to vitamin K deficiency.