SEER Inquiry System - Search

Updated February 2026

For cases diagnosed 2025 and later: Assign behavior /1 for solitary fibrous tumor unless stated to be malignant or have metastasized.

A review by the Cancer PathCHART expert neuropathologists found behavior code /0 is incorrect and both solitary fibrous tumor grade 1 and grade 2 are coded as 8815/1. WHO Classification of Central Nervous System Tumors, 5th edition, assigns behavior as /1 and no longer recommends terms solitary fibrous tumor/hemagiopericytoma and hemagiopericytoma. The STR table is correct. Future updates to ICD-O should reflect this behavior.

WHO Classification of Tumours, Central Nervous System Tumours, 5th ed. was reviewed by the CPC expert pathologists for implementation for cases diagnosed January 1, 2025.

Reminder: Comparing the CPC Validity Status included in the 2024 CPC*Search to that included in the 2025 SMVL (that table that drives the edits) is incorrect. CNS Tumors were not reviewed for 2024 implementation, they were reviewed for 2025 implementation. There will be a 2025 CPC*Search and a /1 will be designated as a Valid.

Assign 8020/3 for SMARCA4- deficient malignant neoplasms of the esophagus.

The WHO Classification of Digestive System Tumors, 5th edition, lists undifferentiated carcinoma as 8020/3. Undifferentiated carcinoma of the esophagus is characterized by the frequent loss of SMARCA4 or SMARCA2 by immunohistochemistry.

SINQ 20200057 was updated in August 2025 and assigns code 8044/3 for Thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). The 2025 Solid Tumor Manual includes SMARCA4-deficient or SMARCB1-deficient tumors for thoracic and sinonasal sites (8044/3).

Assigning histology to other individual sites should be on a case-by-case basis.

Do not assign a behavior code of /2 to these cases unless you have a way to flag them so that they are not reported to the standard setters as in situ cases. Work with your state central registry to ensure that these cases are not unintentionally included in state case submission.

Assign code 01 (White) for Race 1 when described as Indigenous-Latino/a or Indigenous-Latinx. Indigenous-Latinx is an umbrella term for Indigenous migrants to the United States from Latin America including South and Central America, the Caribbean, and Mexico (for example, Maya, Mixteco, Purépecha, Taino, Zapoteco, etc.). Latin America is listed in Appendix D of the 2025 SEER Manual as White.

Assign code 6 (Spanish, NOS; Hispanic, NOS; Latino, NOS) for Spanish Surname or Origin for Indigenous-Latino/a or Indigenous-Latinx in the absence of more specific information. Code 6 description includes the statement, There is evidence, other than surname or birth surname (maiden name), that the person is Hispanic but he/she cannot be assigned to any of the categories 1-5.

Assign code 03 (American Indian or Alaska Native) when described as First Nations. First Nations usually refers to Indigenous peoples for ethnic groups who are the original or earliest known inhabitants of an area. The term ‘First Nations’ can be applied to individuals, but technically refers only to those who have Indian status under Canadian law as part of a recognized community. Within Canada, the term First Nations is generally used for Indigenous peoples other than Inuit and Métis. Outside Canada, the term can refer to Indigenous Australians, U.S. tribes within the Pacific Northwest, as well as supporters of the Cascadian independence movement. 

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.

Code 550 is missing “< equal to 6 cm.” In addition, code 650 should include ipsilateral lymph nodes as well.

Revised codes:

Code 550

CLINICAL ASSESSMENT only

Bilateral or contralateral lymph nodes, < equal to 6 cm WITH clinical evidence of ENE

Code 650

CLINICAL ASSESSMENT only

Ipsilateral, Bilateral or Contralateral lymph nodes > 6 cm WITH or WITHOUT clinical evidence of ENE

These changes will be implemented in Version 3.4 (October 2026). We apologize for the error.

Code meningioma, NOS (9530/0) based on the integrated diagnosis and histological classification. WHO Classification of Central Nervous System Tumors, 5th edition, states that brain invasion is a criterion for the diagnosis of CNS WHO grade 2 meningioma, and there is no statement of brain invasion, atypical meningioma, or other WHO grade 2 lesions. WHO has not proposed behavior codes based on WHO grade alone.

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.

Refer to the College of American Pathologists (CAP) protocols to determine how to interpret p16 staining results on pathology reports. Per the Vulva CAP Protocol, p16 positive is defined as diffuse or block-like expression. Since the pathology report states "block-like expression," code the histology as 8085/3 (invasive squamous cell carcinoma, HPV-associated).

Report the case when the differential diagnosis includes only reportable neoplasms in the absence of additional information. We are unable to provide general instructions for provisional diagnoses as each situation will need to be reviewed and assessed individually when no further work-up information is available.

Assign myeloid leukemia, NOS (9860/3) to the case described in the example. Assign a generic histology code because a specific histology code cannot be assigned when there are several differential diagnoses. Since the differential diagnoses include a chronic and an acute leukemia, code as myeloid leukemia, NOS since it is not clear if this is chronic or acute.