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SEER Inquiry System - Report
Produced: 05/27/2026 10:04 AM
Question 20110035
Inquiry Details
References:
Heme & Lymph Manual & DB
Question:
Discussion:
Answer:
Updated May 2026
Code the primary site to C421 [bone marrow] and histology to 9823/3 [CLL/SLL]. Per Rule PH5 there may be involvement of bone marrow AND lymph node(s), lymph node region(s), organ(s), or tissue(s) but as long as the peripheral blood and/or bone marrow are involved, the primary site is bone marrow (C421).
History:
For cases diagnosed 2010-2011, access the Hematopoietic Database at http://seer.cancer.gov/tools/heme/. Click on Hematopoietic Project. Click on Hematopoietic and Lymphoid Database. For 2010-2011 diagnoses, click on the "use the 2010 database" label in the upper right corner of the screen. The 2010 Hematopoietic Coding Manual (PDF) button will appear to indicate the correct version of the program is available now for query.
Code the primary site to C421 [bone marrow] and histology to 9823/3 [CLL/SLL] because this patient is manifesting both leukemia and lymphoma symptoms/involvement. The steps used to arrive at this decision are:
Enter in to the Heme DB to search for the histology. Click on the SEARCH button. The term "chronic lymphocytic leukemia/small lymphocytic lymphoma" [9823/3] will be highlighted.
Check the PRIMARY SITE section which indicates the site should be C421.
Confirm the final decision regarding the site and histology in the rules.
Click on the 2010 HEMATOPOIETIC CODING MANUAL (PDF) button. Once in the manual, locate one of the three formats (i.e., flowchart, matrix or text) to check the Multiple Primary Rules. The rules are intended to be reviewed in consecutive order from Rule PH9 to PH12 in Module 3. Stop at the first rule that applies to the case you are processing.
. Per this rule, code the primary site bone marrow (C421) and code the histology B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (BCCLL/CLL) [9823/3] when the diagnosis is B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma (BCCLL/SLL) AND peripheral blood is involved (the bone marrow may also be involved).
Rule PH9 will be modified to say that when there is involvement of only blood and/or bone marrow OR involvement of both bone marrow and/or blood and solid tissue, code to CLL/SLL.
