#1: Multiple primaries
#2: Heme & Lymphoid Neoplasms
Source 1: Heme & Lymphoid Manual and Database
Notes: September 2020; Effective with Cases Diagnosed 1/1/2010 and Forward
Multiple primaries--Heme & Lymphoid Neoplasms--Lymphoma: Is a case initially submitted as C772 with histology coded 9591/3 (lymphoma, NOS) with a second case submitted as C162 with histology coded 9699/3 (extranodal marginal zone lymphoma of mucosal-associated lymphoid tissue (MALT lymphoma) a single primary or multiple primaries? See Discussion.
The following cases were submitted to the central registry as separate primaries. First case submitted as C772 with histology coded 9591/3 (Lymphoma, NOS). Second case submitted as C162 with histology coded 9699/3 (MALT Lymphoma).
Sequence 01 - 5/2016, Excisional biopsy pancreatic tail lymph node: suspicious for malignant B-cell lymphoma. No treatment recommended or administered.
Sequence 02 - 2/2019, Stomach biopsy: MALT Lymphoma. Unknown if treatment was recommended or administered. Biopsy was only at this facility.
Using the Hematopoietic and Lymphoid Neoplasm Multiple Primaries/Histology rules, Rule M7 makes this a single primary. Note 4 instructs to change the histology of the initial abstract to the more specific histology (9699/3). If this is done, they would be multiple primaries per the exception within Rule M2. Should the histology on sequence 01 be changed to the MALT lymphoma and the cases would be multiple primaries or is this a single primary?
Abstract two primaries and assign
Primary 1: C772, 9699/3
Primary 2: C162, 9699/3
Per Rule M7, you would change the first case to histology 9699/3 based on Note 4 under Rule M7, Note 4: Change the histology code on the original abstract to the more specific histology when the original diagnosis is in your registry database. Use previous editions of ICD-O (i.e., ICD-O-1, ICD-O-2) or the Hematopoietic Database to assign the code applicable to the year of diagnosis for the more specific histology.
Per Rule M2 this would be the same primary based on both being the same histology; however, there is an exception for MALT lymphomas (9699/3), which states: Abstract multiple primaries when a nodal MALT (C770-779, 9699/3) occurs before or after an extranodal MALT (all other sites, 9699/3).