SEER Inquiry System - Search

1.  The 2022 and 2023 SEER Program Coding Manuals state under Histologic Type ICD-O-3: Beginning with cases diagnosed 01/01/2022 forward, p16 test results can be used to code squamous cell carcinoma, human papilloma virus (HPV) positive (8085) and squamous cell carcinoma, HPV negative (8086).

NAACCR 2023 Implementation Guidelines contain similar instructions on HPV histologies for cervix, vulva and vagina that are applicable back to 2022 (2021 for cervix).

The current Other Sites Solid Tumor Rules state on the Histology tables for anus, cervix, vagina, vulva, and penis and scrotum: "p16 is a valid test to determine HPV status and can be used to code HPV associated and HPV independent histologies." Since Other Sites Solid Tumor Rules apply to cases diagnosed 2023+, can p16 results only be used from 2023 onward, to code HPV-related histologies for primaries that fall under the Other Sites module? Or per the 2022 SEER Manual statement and NAACCR 2023 Implementation Guidelines, could a p16-confirmed HPV histology code also apply to a 2022 Other Sites case and if so, is that only for cervix, vulva, and vagina? Further complicating the matter are the 2024 ICD-O-3.2 update documents indicating these codes are valid 1/1/2024+ for the “Other Sites” penis and scrotum.

2.  Is using p16 testing for HPV-related histology codes ONLY allowed for sites in the Solid Tumor tables that contain the statements about p16 (Head & Neck Table 5, and the Other Sites tables noted above for anus, cervix, etc.)? Or could it apply to primary sites outside of those tables; for example, a 2022 pathology report from the ethmoid sinus C311 indicating an HPV-related histology based on p16 testing? The ICD-O-3 Annotated Histology lists include C310-C313 among the common site codes for 8085 and 8086. The Head and Neck Solid Tumor Rules “New for 2022” section and rule H1 Note 4 also mention that p16 can be used to code HPV histologies; these sections would seem to apply to all sites in that module, since only the more common histology codes are listed in the tables and if not, we are instructed to use ICD-O.

In 01/2023, right lower lobectomy final diagnosis proved a single adenocarcinoma tumor with the histological patterns described as acinar (20%), papillary (30%) and solid; complex glands (cribriform and fused glands) (50%). There is no H Rule applicable to a complex glandular pattern adenocarcinoma. Is this equivalent to a solid predominant adenocarcinoma (8230) per Rule H7? Or is the predominant adenocarcinoma a mixed subtype coded as 8255 per Rule H9?

Small cell carcinoma is a specific type of neuroendocrine carcinoma for the lung. However, Table 3 lists neuroendocrine carcinoma, NOS as the more specific subtype/variant in Column 3.

Using Lung Solid Tumor Rules, Rule H6, a diagnosis of poorly differentiated neuroendocrine carcinoma (small cell carcinoma)” would be coded as 8246, instead of 8041, because there are two histologies under consideration (an NOS and a subtype/variant in Table 3), and the rule tells us to code the subtype/variant. However, small cell carcinoma is more specific than the NOS diagnosis (neuroendocrine carcinoma, NOS). Should Table 3 be updated to reflect which histology is the NOS and which is the more specific?

There is no statement of mucinous or non-mucinous in this case, only adenocarcinoma in situ and an obsolete term bronchioloalveolar carcinoma (BAC) which used to be code 8250. However 8250 is now lepidic adenocarcinoma, and does not match this diagnosis.

Although the Histology Rules do include a general note indicating that the preferred term for BAC is now mucinous adenocarcinoma 8253, it is not listed as a synonym in Table 3. As a result it is unclear how to apply this statement in accordance with the H rules.

The ICD-O Histology Updates table also includes Bronchiolo-alveolar carcinoma, non-mucinous which seems to suggest that in order to apply histology code 8252 (non-mucinous) or 8253 (mucinous) one must also have a statement of mucinous or non-mucinous.

SINQ #20170064 states this should be coded as neuroendocrine carcinoma for rectum, but that may not apply for a 2018+ lung case. The Solid Tumor Manual lists "neuroendocrine tumor, grade 3" as 8249 in the Lung module, Table 3, but our pathology report does not specify grade 3 and we are unsure if that would be equivalent to "high grade" in this case. We were unable to find this exact term in the Solid Tumor Manual or the ICD-O-3.2 update documents.

The resection pathology report final diagnosis indicates this is both mixed mucinous and non-mucinous with a lepidic predominant component. The pathologist notes this is “Lepidic: 75%. Acinar: 25%.”  The percentage of the mucinous component is not documented.

Rule H1, Note 1, states “When mucinous carcinoma is mixed with another histology, such as adenocarcinoma and mucinous carcinoma, code mucinous ONLY when mucinous is documented to be greater than 50% of the tumor.” While mixed invasive mucinous and non-mucinous carcinoma is included in Table 2 (Combination/Mixed Histology Codes) without a required percentage, it is unclear whether one should move past Rule H7 and use Rule H8 to code this combination histology code. Rule H7 would instruct one to code the histology to lepidic adenocarcinoma (adenocarcinoma, lepidic predominant) based on the percentage of the lepidic component in the tumor. However, this does not address the mixed mucinous and non-mucinous diagnosis. Which H Rule and histology apply to this case?

The Solid Tumor Rules state that for cases diagnosed in 2022 and forward, p16 testing CAN be used to assign histology code 8085 (squamous cell carcinoma, HPV positive). The rules also state that for cases diagnosed prior to 1/1/2022, code 8085 MUST be based on ISH testing and not p16. ISH testing is not specifically addressed for 2022+ cases, but are we correct in assuming it can still be used as the basis for 8085?

Multiple CAnswer Forum posts and the AJCC 8th edition Head and Neck staging webinar indicate that the correct chapter/registry staging schema in this situation is determined ONLY by p16 results - not ISH testing, and therefore the Schema Discriminator 2 SSDI should be coded as 1 – p16 negative, regardless of ISH results.

While we understand that histology codes should not be changed based on staging criteria, there is a SEER/NAACCR edit, “Schema Discriminator 2, Head and Neck, Histology (NAACCR)” tag number N6802, that will not allow coding 8085 if Schema Discriminator 2 is coded as 1 (p16 negative). The edit does seem to be correctly enforcing the AJCC guidelines for choosing the staging schema, based on the sources noted above. Do the Solid Tumor or Site-Specific Data Items (SSDI) guidelines need to be modified for this situation?

There are multiple possible entries (rows) for a tumor with a neuroendocrine component and non-neuroendocrine component, but these rows do not specify which primary sites are applicable. Row 1 (Combined small cell carcinoma, 8045) seems applicable to a prostate primary, but not to a GI primary since GI primaries are now generally referred to as MiNENs (mixed neuroendocrine non-neuroendocrine tumors), but Table 2 does not provide any instructions regarding how to determine the difference between 8045 and 8154 (or 8244).

For SEER Workshop Case 03 (mixed prostate case), many users selected 8154 or 8244 as the mixed histology code per Table 2, but these histology codes are not listed as applicable in Table 3 (Prostate Histologies). Per the WHO Blue Books, these histologies are not listed as applicable to the prostate.

How are registrars to determine the correct mixed code without site designations, especially if they don't have access to the WHO Blue Book or to a pathologist who may be able to clarify the codes?

The accuracy rate for SEER Workshop Case 04 (a duodenal invasive adenocarcinoma in an adenomatous polyp) was very low because Rule H13 was either being ignored or users were stopping at Rule H12 to code adenocarcinoma.

If the presence of an NOS histology in a polyp is still clinically relevant for the Other Sites module, this information will be missed due to the order of the H Rules, or the lack of clarification in Rule H12.

If a change is made to Rule H12 (Single Tumor: Invasive Only module), then changes must also be made to the Single Tumor: In Situ Only module and the Multiple Tumors Abstracted as a Single Primary module because both these modules include the same polyp coding H Rule.

2012 Total abdominal hysterectomy - bilateral salpingo-oophorectomy

Primary Site – Ovary, Right

Histology - Small-Cell Carcinoma (Hypercalcemic Type), Large-Cell Variant

2024 Total abdominal hysterectomy - bilateral salpingo-oophorectomy

Primary Site – Ovary, Left

Histology - Small-Cell Carcinoma (Hypercalcemic Type), Large-Cell Variant