D47.3

HCC Category Mapping

What This Code Means

Essential thrombocythemia is a blood disorder where the bone marrow produces too many platelets, which can lead to abnormal bleeding or clotting. This is a chronic condition that requires ongoing monitoring and management.

Coding Tips

• •Verify documentation specifies 'essential' or 'primary' thrombocythemia to distinguish from secondary causes of high platelet counts
• •Look for associated complications (thrombosis, hemorrhage) that may require additional codes, and confirm whether the patient is on antiplatelet or anticoagulant therapy

Clinical Significance

Essential thrombocythemia is a chronic myeloproliferative neoplasm characterized by persistent thrombocytosis (platelet count above 450,000/microL) due to clonal megakaryocyte proliferation. Despite being considered the most indolent of the myeloproliferative neoplasms, it carries risks of both thrombotic events (stroke, deep vein thrombosis) and paradoxical hemorrhagic complications from acquired von Willebrand disease.

Documentation Requirements

• ✓Documentation should include persistently elevated platelet counts, bone marrow biopsy showing megakaryocyte hyperplasia, and molecular testing (JAK2, CALR, or MPL mutations).
• ✓World Health Organization diagnostic criteria should be met.
• ✓Document cardiovascular risk factors, prior thrombotic events, and current therapy (aspirin, hydroxyurea, anagrelide).
• ✓Rule out reactive thrombocytosis.

Commonly Confused Codes