Essential thrombocythemia (NORD)
00:00 / 00:00
Videos
Notes
Essential thrombocythemia (NORD)
Hematological system
Anemias
Autoimmune hemolytic anemia
Glucose-6-phosphate dehydrogenase (G6PD) deficiency
Hemolytic disease of the newborn
Hereditary spherocytosis
Paroxysmal nocturnal hemoglobinuria
Pyruvate kinase deficiency
Sickle cell disease (NORD)
Fanconi anemia
Folate (Vitamin B9) deficiency
Megaloblastic anemia
Vitamin B12 deficiency
Alpha-thalassemia
Anemia of chronic disease
Beta-thalassemia
Iron deficiency anemia
Lead poisoning
Sideroblastic anemia
Anemia of chronic disease
Aplastic anemia
Diamond-Blackfan anemia
Fanconi anemia
Dysplastic and proliferative disorders
Langerhans cell histiocytosis
Mastocytosis (NORD)
Essential thrombocythemia (NORD)
Myelodysplastic syndromes
Myelofibrosis (NORD)
Polycythemia vera (NORD)
Leukemoid reaction
Leukemoid reaction
Mixed platelet and coagulation disorders
Disseminated intravascular coagulation
Heparin-induced thrombocytopenia
Von Willebrand disease
Thrombosis syndromes (hypercoagulability)
Antiphospholipid syndrome
Antithrombin III deficiency
Factor V Leiden
Protein C deficiency
Protein S deficiency
Hematological system pathology review
Coagulation disorders: Pathology review
Extrinsic hemolytic normocytic anemia: Pathology review
Heme synthesis disorders: Pathology review
Intrinsic hemolytic normocytic anemia: Pathology review
Leukemias: Pathology review
Lymphomas: Pathology review
Macrocytic anemia: Pathology review
Microcytic anemia: Pathology review
Mixed platelet and coagulation disorders: Pathology review
Myeloproliferative disorders: Pathology review
Non-hemolytic normocytic anemia: Pathology review
Plasma cell disorders: Pathology review
Platelet disorders: Pathology review
Thrombosis syndromes (hypercoagulability): Pathology review
Assessments
Essential thrombocythemia (NORD)
Flashcards
0 / 11 complete
USMLE® Step 1 questions
0 / 2 complete
Flashcards
Essential thrombocythemia (NORD)
of complete
Questions
USMLE® Step 1 style questions USMLE
of complete
| Laboratory value | Result |
| Hemoglobin | 9.5 g/dL |
| Hematocrit | 28.5% |
| Leukocytes | 2,700/mm3 |
| Platelets | 100,000/mm3 |
Biopsy of the bone marrow biopsy shows increased fibrosis and reduced cell count. Polymerase chain reaction testing reveals a mutation in a gene encoding for a non-receptor tyrosine kinase. Which of the following diseases is also caused by an identical mutation?
External References
First Aid
2022
2021
2020
2019
2018
2017
2016
Bleeding
essential thrombocythemia p. 441
Essential thrombocythemia p. 441
Thrombosis
essential thrombocythemia p. 441
Transcript
Content Reviewers
Contributors
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 creating platelets.
In essential thrombocythemia there’s a genetic mutation that occurs in the Janus Kinase 2 gene, also called JAK2, or somewhere along this pathway of cell signalling.
Normally, the liver and kidneys produce a a tiny hormone called thrombopoietin which binds to hematopoietic cell receptors.
When it binds, those cells activate the JAK2 gene which makes them divide and mature into megakaryocytes and platelets.
Cells can also develop mutations in the thrombopoietin receptor, MPL, or in the chaperone protein, Calreticulin or CalR.
Now, when there’s a genetic mutation in CalR, the signalling pathway remains active all the time, and that means that platelets keep getting produced even in the absence of thrombopoietin.
Although there are lots of platelets that are made, many of them end up being misshapen - they’re large and irregularly shaped.
Now, all of these excess platelets end up causing an increased risk of blood clots in the deep veins of the legs, lungs, and even sites where clots don’t usually form, like the abdomen.
As a result, there’s an increased risk of stroke, heart attack, and miscarriage.
Now, if the number of platelets is extremely high, over 1.5 million, then there’s an increased risk of bleeding.
For Institutions
Copyright © 2023 Elsevier, its licensors, and contributors. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
Cookies are used by this site.
USMLE® is a joint program of the Federation of State Medical Boards (FSMB) and the National Board of Medical Examiners (NBME). COMLEX-USA® is a registered trademark of The National Board of Osteopathic Medical Examiners, Inc. NCLEX-RN® is a registered trademark of the National Council of State Boards of Nursing, Inc. Test names and other trademarks are the property of the respective trademark holders. None of the trademark holders are endorsed by nor affiliated with Osmosis or this website.
