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SEER Inquiry System - Report
Produced: 03/10/2026 10:23 AM
Question 20190070
Inquiry Details
References:
#1: WHO Class Hem & Lymph Tumors, 291. 4th edition
#2: Heme & Lymph Manual & DB. Accessed 10/3/2019
Question:
Histology--Heme & Lymphoid Neoplasms: How is the histology coded for a when the pathologist notes the low grade B-cell lymphoma raises the possibilities of extranodal marginal zone lymphoma of mucosa associated tissue (MALT lymphoma) and lymphoplasmacytic lymphoma (LPL)? See Discussion.
Discussion:
Rule PH28 confirms the more specific histologies are ignored if this is truly a low grade B-cell lymphoma (i.e., non-Hodgkin lymphoma, NOS) since both MALT lymphoma and LPL are more specific types of low grade B-cell lymphomas. This leaves only a diagnosis of low grade B-cell lymphoma with plasmacytic differentiation to consider.
SINQ 20130033 states a low grade B-cell lymphoma with plasmacytic differentiation should be coded as 9680/3 (diffuse large B-cell lymphoma (DLBCL)). However, DLBCL is a high grade B-cell lymphoma, not a low grade B-cell lymphoma.
If the pathologist classifies this as a non-specific low grade B-cell lymphoma, and clarifies that this may represent a more specific type of low grade B-cell lymphoma (MALT lymphoma or LPL), should the histology be coded to a high-grade lymphoma (DLBCL) or non-Hodgkin lymphoma, NOS?
Answer:
Code low grade B-cell lymphoma with plasmacytic differentiation as 9591/3 (Non-Hodgkin lymphoma, NOS). Plasmacytic differentiation is commonly seen with B-cell neoplasms. If further information identifies a more specific histology, the abstract can be updated to reflect the more specific histology.
In the latest WHO Classification of Tumors of Hematopoietic and Lymphoid Tissues, 4th ed., there is confirmation that DLBCL is a high grade B-cell neoplasm. We will update the SINQ question.
