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Essential thrombocythemia (NORD)




Hematological system

Heme synthesis disorders
Coagulation disorders
Platelet disorders
Mixed platelet and coagulation disorders
Thrombosis syndromes (hypercoagulability)
Leukemoid reaction
Dysplastic and proliferative disorders
Plasma cell dyscrasias
Hematological system pathology review

Essential thrombocythemia (NORD)


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Essential thrombocythemia (NORD)

11 flashcards

USMLE® Step 1 style questions USMLE

2 questions

A 51-year-old female comes to the emergency department because of shortness of breath that began an hour ago. Three days ago, the patient returned from a business trip in Europe. Past medical history is notable for hypertension. The patient has been taking oral estrogen for management of menopausal symptoms. Her temperature is 37.8°C (100.0°F), blood pressure is 148/89, pulse is 130/min, and respiratory rate is 27/min. Oxygen saturation is 86% on room air. Physical examination reveals splenomegaly. Coagulation studies show a prothrombin time (PT) of 12 seconds and partial thromboplastin time (PTT) of 34 seconds. A peripheral blood smear shows the following:  

 Reproduced from: Wikimedia Commons  

Computed tomography subsequently confirms the presence of a pulmonary embolus. Which of the following best explains the pathophysiology of this patient presentation? 

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Content Reviewers:

Rishi Desai, MD, MPH

Essential thrombocythemia is a slowly progressive disease where the bone marrow produces too many platelets.

In rare cases, essential thrombocythemia can develop into myelofibrosis and acute leukemia.

Now, the vast majority of bone marrow is made of hematopoietic cells which are the early progenitor cells that can differentiate into other cell types.

In the case of platelets, progenitor cells differentiate into megakaryocytes, which are responsible for