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SEER Inquiry System - Report
Produced: 10/16/2025 8:37 AM
Question 20200007
Inquiry Details
References:
#1: Heme & Lymph Manual & DB. Effective with cases diagnosed 1/1/2010 and forward
#2: WHO Class Hem & Lymph Tumors, 69. Revised 4th edition
Question:
Multiple primaries--Heme & Lymphoid Neoplasms: How many primaries are accessioned when a patient is simultaneously diagnosed with systemic mastocytosis and chronic myelomonocytic leukemia (CMML-0) on a single bone marrow biopsy? See Discussion.
Discussion:
The Hematopoietic and Lymphoid Neoplasms Database (Heme DB) definition for systemic mastocytosis with an associated hematological neoplasm (SM-AHN, 9741/3) states SM-AHN is a variant of systemic mastocytosis that arises with a myeloid disease of non-mast cell lineage (e.g., MDS, MPN, etc.) and that,
However, SINQ 20130172 conflicts with the Heme DB stating the systemic mastocytosis and the associated hematological neoplasm are a single primary coded to a single histology (9741/3) per Rule M2.
Answer:
Abstract a single primary when the diagnosis is systemic mastocytosis with an associated clonal hematogoical non-mast cell lineage disease (SM-AHNMD) (9741/3). However, if the patient has a previous history of myelodysplastic syndrome, myeloproliferative neoplasm, myelodysplastic/myeloproliferative neoplasm or acute leukemia, abstract the SM-AHNMD as a second primary as stated in the Heme DB.
SINQ 20130172 represents a single primary as there is no mention of a prior history of myelodysplastic syndrome, myeloproliferative neoplasm, myelodysplastic/myeloproliferative neoplasm or acute leukemia.
