An official website of the United States government
Home
SEER Inquiry System - Report
Produced: 03/17/2026 6:09 AM
Question 20120015
Inquiry Details
References:
Heme & Lymph Manual & DB
Question:
Diagnostic confirmation--Heme & Lymphoid Neoplasms: How does one determine and code a clinical diagnosis for the diagnostic confirmation in patient diagnosed with essential thrombocythemia? See Discussion.
Discussion:
The Heme DB originally stated the Definitive Diagnostic Method is coded to 8 [clinical diagnosis only] while an updated version stated it can coded as a clinical diagnosis or it can be based on the results of a bone marrow biopsy or a genetic test. The Abstractor Note section specifies this is a diagnosis of exclusion. According to a recent Web-based training seminar, the JAK-2 diagnosis would be coded 5 [positive laboratory test/marker study]. Doesn't the Definitive Diagnostic Method of a clinical diagnosis/diagnosis of exclusion mean that the diagnostic confirmation of essential thrombocythemia will always be coded as 8 [clinical diagnosis only]? Many people use code 3 for positive bone marrow biopsy and genetics (JAK-2), but the bone marrow is usually reported as only borderline or is stated to be abnormal for a person's age.
Answer:
For cases diagnosed 2010 and forward, access the Hematopoietic Database at http://seer.cancer.gov/seertools/hemelymph.
Code the diagnostic confirmation to 8 [clinical diagnosis only] in this case.
Per the Heme DB, JAK-2 is only positive in about 50% of essential thrombocythemia (ET) patients. In addition, a positive JAK-2 test does not identify the type of myeloproliferative disease (MPN) the patient has, only the presence or absence of the JAK-2 mutation.
The WHO guidelines for diagnosing ET are: elevated platelet count over months and the elimination of other causes for an elevated platelet count (such as polycythemia vera (PV), chronic myelogenous leukemia (CML), idiopathic myelofibrosis, or myelodysplastic syndrome (MDS)); the absence of Philadelphia chromosome, BCR/ABL fusion gene; and del(5q), t(3;3)(q21;26),inv(3)(q21q26)).
Subsequently, the physician rules out any underlying causes of thrombocytosis such as an inflammation or infection, other neoplasms, and prior splenectomy.
Ultimately, there is a diagnosis of exclusion. In other words, all other causes for the elevated platelet count have been excluded. The physician assembles the information from the blood counts, bone marrow and JAK-2 testing along with the information that excludes all other diseases and makes a clinical diagnosis of ET.
SEER*Educate provides training on how to use the Heme Manual and DB. If you are unsure how to arrive at the answer in this SINQ question, refer to SEER*Educate to practice coding hematopoietic and lymphoid neoplasms. Review the step-by-step instructions provided for each case scenario to learn how to use the application and manual to arrive at the answer provided. https://educate.fhcrc.org/LandingPage.aspx.
