Case Example 6 (Multiple Primaries)

When there are multiple diagnoses, take them in order, and remember, you may have to go through the rules twice.

11/2016 L retroperitoneal node bx: 9685/3 (follicular lymphoma gr 1 of 3). Tx was active surveillance.
7/2019 L inguinal node FNA, 9680/3 (DLBCL). Tx was R-CHOP.
7/2023 L neck, Level 2 node excision: 9691/3 (Follicular lymphoma, gr 1-2 of 3)

Steps to determining number of primaries

Date Diagnosis/Comment Primary
11/2018 Diagnosis from lymph node biopsy is Follicular lymphoma gr 1. Per the Hematopoietic database this is 9695/3 #1
7/2023 Diagnosis from FNA is DLBCL (9680/3).
Go to the Hematopoietic database and review 9680/3. Under the “Transformations from” field, all the follicular lymphomas transform to DLBCL. If you look under 9695/3, you’ll see that the “Transformation to” lists DLBCL. This is a chronic/acute situation.

Rules M8-M13 apply.
There are almost 3 years between the diagnoses, so Rule M10 applies, which is to code the DLBCL as a second primary.

#2
7/2025 Diagnosis is Follicular lymphoma, gr 1-2 of 3
Per the Heme Database this is 9691/3. In the abstractor notes it states “Follicular lymphomas are always the same primary. When there are multiple diagnoses of Follicular lymphoma, update the histology (as needed) to always reflect the highest grade. Known grade always takes priority over the NOS histology.”

This is a same primary per Rule M2; however, the histology needs to be updated to Follicular lymphoma, gr 1-2, which is 9691/3.

 Same primary as #1

Updated: December 2, 2025