Practice questions platelet disorders

Practice questions 

Platelet disorders

© Jun Wang, MD, PhD

1. A 9-year-old boy presents with sudden onset of gum bleeding. He has a history of coughing with running nose two weeks ago. There is no history of trauma. Physical examination reveals a well-nourished boy with normal development. Multiple pin point like hemorrhage spots are seen on his oral mucosa, upper chest and back, as well as arms. Physical examination is otherwise unremarkable. There is no evidence of hematoma. What is most likely abnormal in his laboratory tests?

A. Elevated FDP

B. Leukocytosis

C. Prolonged PT

D. Prolonged PTT

E. Reduced platelets

2. A 17-year-old girl with Turner syndrome presents with nose bleeding for 2 days. She has had a cold and fever 1 week ago, but recovered without any treatment. Her past history is unremarkable. Physical examination reveals pin point hemorrhage at her upper limbs. No lymphadenopathy or splenomegaly is seen. Her CBC reveals normal range hemoglobin and white cell counts. Platelet count is 3 x 10⁹/L (normal 204-402 x 10⁹/L). Peripheral blood smear reveals reduced platelet number. No morphological abnormality is seen in all three lineages. Her other lab tests are within normal range. What is the most likely diagnosis?

A. Acute lymphoblastic leukemia

B. Acute immune thrombocytopenic purpura

C. Hemolytic-uremic syndrome

D. Iron deficiency anemia

E. Thrombotic thrombocytopenic purpura

3. Use this case for the next two questions. A 65-year-old woman presents with fatigue and generalized pain for 3 weeks. She has had one episode of hematuria 3 days ago, and bloody diarrhea 1 week prior. Her past history include hypertension, type I diabetes and anemia. She denies family history of bleeding or malignancy. She does not smoke or use alcohol. Physical examination reveals a blood pressure 130/75 mmHg, heart rate 100 bpm, temperature 98.5 ^oF, and respiratory rate 18 breaths/min. Many pin-point hemorrhage spots are seen in her trunk and upper limbs. No other significant abnormalities are identified. Laboratory tests results include: Hb 7.5 g/L (normal 12-16 g/L), MCV 84 fL (normal 80-96 fL), white count 6.8 x 10⁹/L (normal 5-11 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), PT 11.8 sec (normal 11-13.5 sec), aPTT 28.5 sec (normal 25-35 sec). Peripheral blood smear reveals reduced number of platelets. No morphological abnormality is seen. Bone marrow biopsy reveals normal cellularity with trilineage maturation. The population of megakaryocytes is increased. No morphological abnormality is seen in three lineages. What is the most likely diagnosis?

A. Chronic immune thrombocytopenic purpura

B. Chronic lymphocytic leukemia associated hemolytic anemia

C. Hemolytic-uremic syndrome

D. Heparin-induced thrombocytopenia

E. Myelodysplastic disorder

4. A 65-year-old woman presents with fatigue and generalized pain for 3 weeks. She has had one episode of hematuria 3 days ago, and bloody diarrhea 1 week prior. Her past history include hypertension, type II diabetes and anemia. She denies family history of bleeding or malignancy. She does not smoke or use alcohol. Physical examination reveals a blood pressure 130/75 mmHg, heart rate 100 bpm, temperature 98.5 ^oF, and respiratory rate 18 breaths/min. Many pin-point hemorrhage spots are seen in her trunk and upper limbs. No other significant abnormalities are identified. Laboratory tests results include: Hb 7.5 g/L (normal 12-16 g/L), MCV 84 fL (normal 80-96 fL) white count 6.8 x 10⁹/L (normal 5-11 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), PT 11.8 sec (normal 11-13.5 sec), aPTT 28.5 sec (normal 25-35 sec). Peripheral blood smear reveals reduced number of platelets. No morphological abnormality is seen. Bone marrow biopsy reveals normal cellularity with trilineage maturation. The population of megakaryocytes is increased. No morphological abnormality is seen in three lineages. What is the most likely causing these findings?

A. ADAMTS13 deficiency

B. Autoantibodies against GPIIb/IIIa

C. Endothelial injury

D. Ineffective hematopoiesis

E. Vitamin K deficiency

5. Use this case for the next four questions. A 65-year-old man presents with rapid swelling of right leg two days after sigmoid colon resection for diverticulosis. His past history include prostate cancer and type II diabetes. He drinks beer a can per day for 40 years and smoke cigarette 1 pack a day for 50 years. Physical examination reveals diffuse swelling of right leg. Sonographic examination reveal deep vein thrombosis and he was treated with unfractionated heparin. A week later, he develops shortness of breath and chest tightness. Chest X-ray reveals bilateral pulmonary artery enlargement. CT examination reveal widespread thrombi in lungs. Laboratory studies reveals a reduced platelet count at 72 x 10⁹/L, from 330 x 10⁹/L (normal 150-450 x 10⁹/L) at admission, increased white cell count at 14.5 x 10⁹/L from 7.5 x 10⁹/L (normal 4.5 – 11 x 10⁹/L) at admission. White cell differential is within normal range. His AST is 1270 IU/L (normal 10-40 IU/L), ALT 630 IU/L (normal 10-55 IU/L). His electrolytes, BUN, creatinine, blood glucose and serum PSA are all within normal range. What is most likely causing his exaggerated clinical presentations?

A. Alcoholic liver steatosis and cirrhosis

B. Antibody against a complex containing PF4

C. Bacteria infection

D. Diabetic ketoacidosis

E. Pulmonary metastasis of prostate cancer

6. A 65-year-old man presents with rapid swelling of right leg two days after sigmoid colon resection for diverticulosis. His past history include prostate cancer and type II diabetes. He drinks beer a can per day for 40 years and smoke cigarette 1 pack a day for 50 years. Physical examination reveals diffuse swelling of right leg. Sonographic examination reveal deep vein thrombosis and he was treated with unfractionated heparin. A week later, he develops shortness of breath and chest tightness. Chest X-ray reveals bilateral pulmonary artery enlargement. CT examination reveal widespread thrombi in lungs. Laboratory studies reveals a reduced platelet count at 72 x 10⁹/L, from 330 x 10⁹/L (normal 150-450 x 10⁹/L) at admission, increased white cell count at 14.5 x 10⁹/L from 7.5 x 10⁹/L (normal 4.5 – 11 x 10⁹/L) at admission. White cell differential is within normal range. His AST is 1270 IU/L (normal 10-40 IU/L), ALT 630 IU/L (normal 10-55 IU/L). His electrolytes, BUN, creatinine, blood glucose and serum PSA are all within normal range. What is most likely causing elevations of AST and ALT?

A. Alcoholic liver damage

B. Bacterial toxin cause hepatocyte injury

C. Diabetic vascular changes of liver

D. Ischemic liver damage

E. Liver metastasis of prostate cancer

7. A 65-year-old man presents with rapid swelling of right leg two days after sigmoid colon resection for diverticulosis. His past history include prostate cancer and type II diabetes. He drinks beer a can per day for 40 years and smoke cigarette 1 pack a day for 50 years. Physical examination reveals diffuse swelling of right leg. Sonographic examination reveal deep vein thrombosis and he was treated with unfractionated heparin. A week later, he develops shortness of breath and chest tightness. Chest X-ray reveals bilateral pulmonary artery enlargement. CT examination reveal widespread thrombi in lungs. Laboratory studies reveals a reduced platelet count at 72 x 10⁹/L, from 330 x 10⁹/L (normal 150-450 x 10⁹/L) at admission, increased white cell count at 14.5 x 10⁹/L from 7.5 x 10⁹/L (normal 4.5 – 11 x 10⁹/L) at admission. White cell differential is within normal range. His AST is 1270 IU/L (normal 10-40 IU/L), ALT 630 IU/L (normal 10-55 IU/L). His electrolytes, BUN, creatinine, blood glucose and serum PSA are all within normal range. What is most likely the diagnosis?

A. Acute bronchopneumonia

B. Acute immune thrombocytopenic purpura

C. Hemolytic-uremic syndrome

D. Heparin induced thrombocytopenia

E. Thrombotic thrombocytopenic purpura

8. A 65-year-old man presents with rapid swelling of right leg two days after sigmoid colon resection for diverticulosis. His past history include prostate cancer and type II diabetes. He drinks beer a can per day for 40 years and smoke cigarette 1 pack a day for 50 years. Physical examination reveals diffuse swelling of right leg. Sonographic examination reveal deep vein thrombosis and he was treated with unfractionated heparin. A week later, he develops shortness of breath and chest tightness. Chest X-ray reveals bilateral pulmonary artery enlargement. CT examination reveal widespread thrombi in lungs. Laboratory studies reveals a reduced platelet count at 72 x 10⁹/L, from 330 x 10⁹/L (normal 150-450 x 10⁹/L) at admission, increased white cell count at 14.5 x 10⁹/L from 7.5 x 10⁹/L (normal 4.5 – 11 x 10⁹/L) at admission. White cell differential is within normal range. His AST is 1270 IU/L (normal 10-40 IU/L), ALT 630 IU/L (normal 10-55 IU/L). His electrolytes, BUN, creatinine, blood glucose and serum PSA are all within normal range. What is the most appropriate initial management?

A. Antibiotics administration

B. Insulin administration

C. Plasma exchange

D. Platelet transfusion

E. Stop usage of heparin

9. Use this case for the next five questions. A 40-year-old woman presents with headache and dizziness for 3 days. She has had a bloody diarrhea during an abroad trip. Her past medical history include systemic lupus erythematosus, multiple episodes of spontaneous abortion, and type II diabetes. She is in a difficult legal process of divorce with her husband. Her family history is unremarkable. Physical examination reveal findings consistent with SLE. Multiple bruises are noticed at her arms and legs. No other abnormalities are noted. Laboratory tests results include: Hb at 6.3 g/L (normal 12-16 g/L), MCV 89.7 fL (normal 82-98 fL), reticulocyte count 14% (normal 2-6%), white cell count 5.5 x 10⁹/L (normal 4.5-11.5 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), LDH 1100 U/L (normal 135-250 IU/L), BUN 12 mg/dL (normal 8-18mg/dL), creatinine 0.8 mg/dL (normal 0.6-1.1 mg/dL). Her PT and aPTT are normal. White cell differential is within normal range. Peripheral blood smear reveal red cells with markedly different shape and size, many of red cells appear to be fragmented. Direct Coomb’s test is negative. Urinalysis is positive for hemoglobin. Fecal microbiology studies are negative. What is most likely causing her presentations?

A. Abnormal platelet aggregates due to ultra large von Willebrand multimers

B. Autoantibody against platelet glycoprotein IIb/IIIa

C. Bacterial toxin caused endothelial injury

D. Domestic abuse

E. Spectrin mutation

10. A 40-year-old woman presents with headache and dizziness for 3 days. She has had a bloody diarrhea during an abroad trip. Her past medical history include systemic lupus erythematosus, multiple episodes of spontaneous abortion, and type II diabetes. She is in a difficult legal process of divorce with her husband. Her family history is unremarkable. Physical examination reveal findings consistent with SLE. Multiple bruises are noticed at her arms and legs. No other abnormalities are noted. Laboratory tests results include: Hb at 6.3 g/L (normal 12-16 g/L), MCV 89.7 fL (normal 82-98 fL), reticulocyte count 14% (normal 2-6%), white cell count 5.5 x 10⁹/L (normal 4.5-11.5 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), LDH 1100 U/L (normal 135-250 IU/L), BUN 12 mg/dL (normal 8-18mg/dL), creatinine 0.8 mg/dL (normal 0.6-1.1 mg/dL). Her PT and aPTT are normal. White cell differential is within normal range. Peripheral blood smear reveal red cells with markedly different shape and size, many of red cells appear to be fragmented. Direct Coomb’s test is negative. Urinalysis is positive for hemoglobin. Fecal microbiology studies are negative. What addition test is most helpful for making her diagnosis?

A. ADAMTS-13 activity

B. Antibody for GPIIb/IIIa

C. Blood and urine culture for Escherichia coli O157:H7 and Shigella dysenteriae

D. Levels of alternative complement pathway factors

E. Radiologic workup for old fractures

11. A 40-year-old woman presents with headache and dizziness for 3 days. She has had a bloody diarrhea during an abroad trip. Her past medical history include systemic lupus erythematosus, multiple episodes of spontaneous abortion, and type II diabetes. She is in a difficult legal process of divorce with her husband. Her family history is unremarkable. Physical examination reveal findings consistent with SLE. Multiple bruises are noticed at her arms and legs. No other abnormalities are noted. Laboratory tests results include: Hb at 6.3 g/L (normal 12-16 g/L), MCV 89.7 fL (normal 82-98 fL), reticulocyte count 14% (normal 2-6%), white cell count 5.5 x 10⁹/L (normal 4.5-11.5 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), LDH 1100 U/L (normal 135-250 IU/L), BUN 12 mg/dL (normal 8-18mg/dL), creatinine 0.8 mg/dL (normal 0.6-1.1 mg/dL). Her PT and aPTT are normal. White cell differential is within normal range. Peripheral blood smear reveal red cells with markedly different shape and size, many of red cells appear to be fragmented. Direct Coomb’s test is negative. Urinalysis is positive for hemoglobin. Fecal microbiology studies are negative.

Additional tests reveal ADAMTS-13 level at 9%. What is most likely causing this finding?

A. Acquired mutation of ADAMTS-13 gene

B. Autoantibody against ADAMTS-13

C. Inherited ADAMTS-13 deficiency

D. Shiga-like toxin induced ADAMTS-13 depletion

12. A 40-year-old woman presents with headache and dizziness for 3 days. She has had a bloody diarrhea during an abroad trip. Her past medical history include systemic lupus erythematosus, multiple episodes of spontaneous abortion, and type II diabetes. She is in a difficult legal process of divorce with her husband. Her family history is unremarkable. Physical examination reveal findings consistent with SLE. Multiple bruises are noticed at her arms and legs. No other abnormalities are noted. Laboratory tests results include: Hb at 6.3 g/L (normal 12-16 g/L), MCV 89.7 fL (normal 82-98 fL), reticulocyte count 14% (normal 2-6%), white cell count 5.5 x 10⁹/L (normal 4.5-11.5 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), LDH 1100 U/L (normal 135-250 IU/L), BUN 12 mg/dL (normal 8-18mg/dL), creatinine 0.8 mg/dL (normal 0.6-1.1 mg/dL). Her PT and aPTT are normal. White cell differential is within normal range. Peripheral blood smear reveal red cells with markedly different shape and size, many of red cells appear to be fragmented. Direct Coomb’s test is negative. Urinalysis is positive for hemoglobin. Fecal microbiology studies are negative.

Additional tests reveal ADAMTS-13 level at 7%. What is most likely the diagnosis?

A. Acute immune thrombocytopenic purpura

B. Hemolytic-uremic syndrome

C. Iron-deficiency anemia

D. Myelodysplastic disorder

E. Thrombotic thrombocytopenic purpura

13. A 40-year-old woman presents with headache and dizziness for 3 days. She has had a bloody diarrhea during an abroad trip. Her past medical history include systemic lupus erythematosus, multiple episodes of spontaneous abortion, and type II diabetes. She is in a difficult legal process of divorce with her husband. Her family history is unremarkable. Physical examination reveal findings consistent with SLE. Multiple bruises are noticed at her arms and legs. No other abnormalities are noted. Laboratory tests results include: Hb at 6.3 g/L (normal 12-16 g/L), MCV 89.7 fL (normal 82-98 fL), reticulocyte count 14% (normal 2-6%), white cell count 5.5 x 10⁹/L (normal 4.5-11.5 x 10⁹/L), platelet count 65 x 10⁹/L (normal 150-450 x 10⁹/L), LDH 1100 U/L (normal 135-250 IU/L), BUN 12 mg/dL (normal 8-18mg/dL), creatinine 0.8 mg/dL (normal 0.6-1.1 mg/dL). Her PT and aPTT are normal. White cell differential is within normal range. Peripheral blood smear reveal red cells with markedly different shape and size, many of red cells appear to be fragmented. Direct Coomb’s test is negative. Urinalysis is positive for hemoglobin. Fecal microbiology studies are negative.

Additional tests reveal ADAMTS-13 level at 9%. What is contraindicated in her management?

A. Corticosteroid

B. Cryopoor plasma

C. Plasma exchange

D. Platelet transfusion

14. Use this case for the next three questions. A 7-year-old girl presents with lower back pain, dark urine and severe fatigue for 1 day. She has had vomiting and bloody diarrhea for a few days that stopped 2 days ago. She had picnic at a farm a week ago with her parents during a local event where children can pet farm animals and ride ponies. Her mother developed bloody diarrhea as well but recovered without complications. Physical examination reveal a blood pressure at 160/110 mmHg and pallor of skin. No other abnormality is noted. Laboratory tests results include: Hb 9g/dL (normal 11-13 g/dL), platelets 64 x 10⁹/L (normal 183-369 x 10⁹/L), white cell count 14.5 x 10⁹/L (normal 4.7-10.3 x 10⁹/L) with normal range differential, LDH 3200 U/L (normal 135-250 IU/L), BUN 122 mg/dL (normal 8-18mg/dL), creatinine 1.8 mg/dL (normal 0.6-1.1 mg/dL). Her other laboratory tests including PT and aPTT are normal. Peripheral blood smear reveals low quantity of platelets and moderate schistocytosis. No immature white cells are seen. What is most like causing her reduced number of platelets?

A. Abnormal activation of platelets by antibody against complex of heparin and platelet factor 4

B. Aggregates of platelets by ultra large von Willebrand factor multimers

C. Destruction of platelet by autoantibody against platelet GPIIb/IIIa

D. Medication associated megakaryocytes suppression

E. Shiga-like toxin associated endothelial injury caused platelet aggregates

15. A 7-year-old girl presents with lower back pain, dark urine and severe fatigue for 1 day. She has had vomiting and bloody diarrhea for a few days that stopped 2 days ago. She had picnic at a farm a week ago with her parents during a local event where children can pet farm animals and ride ponies. Her mother developed bloody diarrhea as well but recovered without complications. Physical examination reveal a blood pressure at 160/110 mmHg and pallor of skin. No other abnormality is noted. Laboratory tests results include: Hb 9g/dL (normal 11-13 g/dL), platelets 64 x 10⁹/L (normal 183-369 x 10⁹/L), white cell count 14.5 x 10⁹/L (normal 4.7-10.3 x 10⁹/L) with normal range differential, LDH 3200 U/L (normal 135-250 IU/L), BUN 122 mg/dL (normal 8-18mg/dL), creatinine 1.8 mg/dL (normal 0.6-1.1 mg/dL). Her other laboratory tests including PT and aPTT are normal. Peripheral blood smear reveals low quantity of platelets and moderate schistocytosis. No immature white cells are seen. What addition test is most helpful for making her diagnosis?

A. ADAMTS-13 activity testing

B. Bone marrow biopsy to rule out myelodysplastic disorder

C. ELISA for heparin-PF4 antibody

D. Flow cytometry for lymphoblasts

E. Stool analysis for shiga-toxin producing bacteria

16. A 7-year-old girl presents with lower back pain, dark urine and severe fatigue for 1 day. She has had vomiting and bloody diarrhea for a few days that stopped 2 days ago. She had picnic at a farm a week ago with her parents during a local event where children can pet farm animals and ride ponies. Her mother developed bloody diarrhea as well but recovered without complications. Physical examination reveal a blood pressure at 160/110 mmHg and pallor of skin. No other abnormality is noted. Laboratory tests results include: Hb 9g/dL (normal 11-13 g/dL), platelets 64 x 10⁹/L (normal 183-369 x 10⁹/L), white cell count 14.5 x 10⁹/L (normal 4.7-10.3 x 10⁹/L) with normal range differential, LDH 3200 U/L (normal 135-250 IU/L), BUN 122 mg/dL (normal 8-18mg/dL), creatinine 1.8 mg/dL (normal 0.6-1.1 mg/dL). Her other laboratory tests including PT and aPTT are normal. Peripheral blood smear reveals low quantity of platelets and moderate schistocytosis. No immature white cells are seen. What is most likely the diagnosis?

A. Acute lymphoblastic leukemia

B. Acute immune thrombocytopenic purpura

C. Hemolytic-uremic syndrome

D. Heparin induced thrombocytopenia

E. Thrombotic thrombocytopenic purpura

Answers

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