Diagnosis of Essential Thrombocythemia (ET)

How to Subscribe
MLS & MLT Comprehensive CE Package
Includes 145 CE courses, most popular
$95Add to cart
Pick Your Courses
Up to 8 CE hours
$50Add to cart
Individual course$20Add to cart
Need multiple seats for your university or lab? Get a quote
The page below is a sample from the LabCE course Myeloproliferative Neoplasms. Access the complete course and earn ASCLS P.A.C.E.-approved continuing education credits by subscribing online.

Learn more about Myeloproliferative Neoplasms (online CE course)
Diagnosis of Essential Thrombocythemia (ET)

Detection of ET is often made during routine CBC evaluation since symptoms may not initially appear. Symptoms, when they do occur, commonly include:
  • Thrombosis
  • Abnormal bleeding
  • Headaches
  • Tingling in the extremities
  • Pain in the extremities
Peripheral Blood Findings
The platelet count is greater than 600 x 109/L, frequently 1,000 - 5,000 x 109/L. Giant, bizarre platelets, platelet clumps, megakaryocytes or their fragments may be observed on the peripheral blood smear. Giant platelets are indicated by the arrows in the image on the right. Leukocytosis, erythrocytosis, or slight anemia may also be present. Since platelet counts are so high, the spleen can experience thrombotic episodes which eventually results in splenic atrophy. When this occurs, abnormal red cell morphologies such as red cell inclusions, nucleated red cells, and poikilocytosis, may be observed on the peripheral blood smear.

About half of patients diagnosed with ET have a JAK2(V617F) mutation. CALR and MPL mutations are also major findings. Other laboratory findings in ET include:
  • Normal or slightly increased thrombopoeitin
  • Usually normal prothrombin time (PT) and activated partial thromboplastin time (aPTT)
  • Platelet aggregation: abnormal with adenosine diphosphate, epinephrine, and collagen
  • Increased serum cobalamin, uric acid, LD, acid phosphatase
  • Philadelphia chromosome negative, BCR/ABL1 fusion gene negative