SEER Inquiry System - Search

Report smoldering WM (9761/3) using the Hematopoietic and Lymphoid Neoplasms Manual and Database (Table B9). Smoldering WM is defined as a poorly described asymptomatic disorder with a high risk of progressing to symptomatic WM requiring treatment. The term “smoldering” refers to the process meaning it is progressing, perhaps slowly, or even at a slower pace than might be expected. Smoldering WM resembles smoldering MM.

Report ovarian mucinous borderline tumor with foci of multifocal intraepithelial carcinoma. The foci of intraepithelial carcinoma makes this reportable. See the list of synonyms for in situ in the SEER Manual, Behavior Code data item.

Code celiac axis lymph nodes as regional in EOD Regional Nodes for liver primaries.

Code dexamethasone in KRd regimen (and any other regimen for multiple myeloma containing dexamethasone) as hormonal therapy. Please note that majority of the regimens for multiple myeloma are not in SEER*Rx currently.

The SEER*Rx entry for KRd regimen was updated to indicate that dexamethasone should be coded. The change was done to correct the contradiction with the SEER manual which states, "Code the hormonal agent given as part of combination chemotherapy (e.g., R-CHOP), whether it affects the cancer cells or not" and the SEER*Rx entry for dexamethasone which directs to code it for multiple myeloma.

Report LR-M unless there is information to the contrary. The American College of Radiology defines LR-M as "probably or definitely malignant, not necessarily hepatocellular carcinoma (HCC)."

Assign code 8020/3 when the histologic type specifically includes the term of poorly differentiated, dedifferentiated, undifferentiated, or anaplastic undifferentiated carcinoma along with carcinoma as terms vary depending on the primary site. When the term poorly differentiated is included in the grade section only of the pathology report or only mentions poorly differentiated carcinoma without further substantiation from a pathology report as in examples 1 and 2, do not use code 8020/3.

The histology code 8020/3 and terms may be used for selected primary sites as included in the Solid Tumor Rules, WHO Classification of Tumors series (latest versions), and the Site/Morphology Validation List including

Nasal cavity

Nasopharynx

Salivary glands

Urinary sites

Colon, rectosigmoid, rectum

Esophagus

Stomach

Gallbladder and extrahepatic bile duct

Pancreas

Thyroid

Ovary

Uterine corpus

Vagina

Uterine cervix (also referred to as unclassifiable in WHO Classification of Female Genital Tumors, 5th ed.)

For sites other than those listed, if the diagnosis is poorly differentiated carcinoma, code 8010/3 and poorly differentiated in the grade field. 

Please understand that AJCC sets the standards for TNM Staging and the Cancer PathCHART (CPC) initiative sets standards for the validity of site and morphology combinations. The statement in the AJCC manual “8240 and 8249 are excluded for topography code C160” means that these two histologies are not staged using the AJCC Staging System. As with numerous other reportable entities that are not staged by AJCC, the case is reportable and a Summary Stage should be assigned. Combinations of C160 with 8240 or 8249 are valid site/histology combinations for registry reporting and should not be discouraged from use if they correspond to the pathologist’s diagnosis. This goes for any other similar note in the AJCC manual. All CPC standards are enforced via the Primary Site, Morphology-Type, Beh ICDO3, 2024 (SEER) N7040 and Histologic Type ICDO3, Primary Site, Date of Diagnosis (NAACCR) N4911 data quality edits. Registrars can also look up the validity of site and morphology combinations using the CPC*Search tool:  https://seer.cancer.gov/cancerpathchart/search/tool/. 

It is important to remember the following.

• ALWAYS code the tumor histology stated by the pathologist/physician
• NEVER change the tumor histology to assign TNM
• Not all tumors or histologies can be staged per TNM
• Cases that cannot be assigned TNM are assigned a summary stage

Assign code 9431/1 for angiocentric glioma. This has been corrected in the 2025 update. Angiocentric glioma was removed from the 9421/1 row and remains in its own row.

Sites may be added to certain combinations when indicated by ClinCORE review for Cancer PathCHART. Please note some sites were added in the 2024 update as a result of PathCHART review. A newly-formed Solid Tumor Editorial Board and its subgroups are currently working to evaluate the Solid Tumor Manual and make recommendations on ways to improve the structure and formatting of the manual and its content.

Follow the rules and instructions in the Other Sites STRs when assigning combination histology codes.

Histology Coding Rules

Use the Histology Coding Rules when assigning combination codes.

Coding Histology Information

Use this section that includes the mixed histology (Table 2) and site-specific histology tables (Tables 3-23) for one or more histologies within a single tumor. Do not use this section in place of the Histology Coding Rules.

While site-specific histology tables, based on current WHO Classification of Tumors books, have been added to Other Sites STRs, not all site groups have individual histology tables; coding may require the use of ICD-O and updates. The histology tables in Other Sites STRs include additional coding instructions and notes to assign the correct ICD-O code when appropriate.

The tables are not meant to be all-inclusive; rather they are intended to address difficult coding situations to facilitate the assignment of the correct histology code.

Table 2: Mixed and Combination Codes Instructions

Once you have identified the histology terms and have been instructed to use Table 2 by the Histology Coding Rules, compare the terms in the diagnosis to the terms in Column 1. When the terms match, use the combination code listed in Column 2. Use adenocarcinoma mixed subtypes 8255 as a “last resort” code.

Assign histology as DLBCL (9680/3) as supported by the WHO Classification of Hematolymphoid Tumors, 5th edition. It is consistent with how it would have been coded in the 4th edition. The Heme Manual and Database currently are based on the 4th edition. Physicians are using the 5th edition blue book, whereas the cancer registry field is not yet at this time.

Regarding the Heme Manual and Database, this type of scenario is not covered because it is part of the 5th edition WHO Blue Book. The database cannot be updated until the 5th edition is approved for implementation (2026).