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SEER Inquiry System - Report
Produced: 05/24/2026 3:51 PM
Question 20140039
Inquiry Details
References:
Heme & Lymph Manual & DB
Question:
Reportability--Heme & Lymphoid Neoplasms: Is a statement of "JAK-2 positive polycythemia" reportable? See discussion.
Discussion:
Polycythemia, NOS is not reportable. However, there is a statement in the Heme Manual Glossary for JAK2 that states, "When JAK2 is positive, the MPN is definitely reportable." Does a positive JAK 2 always mean there is a reportable myeloproliferative disorder or must there also be an associated statement of a reportable neoplasm (e.g., myeloproliferative disorder, polycythemia vera, or essential thrombocythemia)?
Answer:
Updated May 2026
A positive JAK 2 does not always mean there is a reportable myeloproliferative disorder. There must also be an associated statement of a reportable neoplasm (e.g., myeloproliferative disorder, polycythemia vera, or essential thrombocythemia). There are several non-malignant disorders that have positive JAK2 gene mutations.
For additional information about JAK2, see SEER's Glossary for Registrars (seer.cancer.gov/seertools/glossary).
