Essential Thrombocytosis Clinical Presentation

Updated: Aug 11, 2021
  • Author: Asheesh Lal, MBBS, MD; Chief Editor: Emmanuel C Besa, MD  more...
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Approximately 25-33% of patients with essential thrombocytosis (primary thrombocythemia) are asymptomatic at diagnosis. The remainder report vasomotor symptoms or complications from thrombosis or bleeding. Most symptomatic patients present with symptoms that relate to small- or large-vessel thrombosis.

  • Microvascular occlusion of the toes and fingers causes digital pain; gangrene; or erythromelalgia, which is is characterized by burning pain and dusky extremity congestion
  • The pain increases with exposure to heat and improves with cold; a single dose of aspirin may provide relief for several days

Headache is the most common neurologic symptom. Patients also report paresthesias and episodic transient ischemic attacks; transient neurologic symptoms include the following:

  • Unsteadiness
  • Dysarthria
  • Dysphoria
  • Vertigo
  • Dizziness
  • Migraine
  • Syncope
  • Scotoma
  • Seizures

Thrombosis of large veins and arteries is common and may result in occlusion of the leg, coronary, and renal arteries. Other arteries may be involved, including retinal arteries. [19] Venous thrombosis of the splenic, hepatic, or leg and pelvic veins may develop. Priapism is a rare complication. Pulmonary hypertension may result from pulmonary vasculature occlusion.

Bleeding complications are as follows:

  • The gastrointestinal tract is the primary site of bleeding complications; approximately 40% of these patients have duodenal arcade thrombosis, resulting in sloughing of the duodenal mucosa, simulating a duodenal ulcer

  • Other sites of bleeding include the skin, eyes, gums, urinary tract, joints, and brain

  • Bleeding is usually not severe and only rarely requires transfusion

  • The bleeding is generally associated with a platelet count greater than 1 million/µL

Constitutional symptoms occur in 20-30% of patients. Weight loss is unusual. Other symptoms include sweating, low-grade fever, and pruritus.

Pregnancy complications are as follows [20] :

  • Spontaneous abortions increase

  • Placental infarctions may occur, resulting in intrauterine growth retardation and fetal death.

  • In most cases, fetal loss occurs during the first trimester

  • A patient history of spontaneous abortion is the greatest risk factor for subsequent spontaneous abortions

  • Excessive bleeding during delivery is rare

  • Patients with successful pregnancies show a decrease in platelet count



In most patients with essential thrombocytosis, physical examination findings are unremarkable. Approximately 40-50% of patients present with splenomegaly; 20% present with hepatomegaly.



The etiology and predisposing factors for the development of essential thrombocytosis (primary thrombocythemia) remain unclear. Genetic transmission of this disorder is rare, although reports show several families with multiple members affected by essential thrombocytosis (primary thrombocythemia). Research suggests that a thrombopoietin production or receptor abnormality can cause familial essential thrombocytosis (primary thrombocythemia). [21]