SEER Inquiry System - Search

In the 2024 Solid Tumor Rules update, the small cell neuroendocrine carcinoma row in Table 2 was changed. The NOS histology became neuroendocrine carcinoma, NOS (8246) and both large cell and small cell neuroendocrine carcinomas (8013 and 8041, respectively) became the subtype/variants. This change impacts Rule H4 but Rule H4 was not updated. Rule H4 still refers to small cell neuroendocrine carcinoma as being the NOS histology.

In the prior STR versions, it was clear the tumor in question would be coded as 8045 per Rule H4 and Table 2. Considering Rule H4 was not updated according to the changes for Table 2, does histology 8045 still apply to this diagnosis?

There is currently no way to arrive at a histology for this case. Does Rule H4, bullet 3 need to be updated to indicate, “subtype/variant of neuroendocrine carcinoma mixed with any other carcinoma (does not apply to sarcoma)”?

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.

In the examples below, are these a single or multiple primaries?

Example 1:

Tumor 1:  C509/left breast, 8520/2 (in situ lobular carcinoma), dx date-01/10/2019

Tumor 2:  C509/ left breast, 8500/3 (carcinoma NST), dx date-08/19/2021

Example 2:

Tumor 1:  C509, right breast, 8520/2, dx date 06/26/2014

Tumor 2:  C508, right breast, 8500/3, dx date-05/23/2019

There seems to be some conflicting info on this. In the 2020 Breast Rules there was a note add to the revision history. “M10 Same behavior requirement re-added.” Which is not in the rules now, nor was it noted to the revision changes in the last two change logs.

Inquiry 20200070 would seem to indicate that this is multiple primaries, but that contrasts with 20230010 which would seem to indicate a single primary, and an ASK A SEER Registrar question that we received a response to. I don’t see a scenario where rule M17, an invasive tumor DX more than 60 days after an in situ tumor would come into play.

If behavior no longer applies to rule M10, at what point did that change get made? Please advise.

Patient had a mandibular mucosal lesion resected in June of 2023, with a diagnosis of “atypical squamous proliferation” and case was forwarded to an expert in oral pathology for best classification. Subsequent slide review final diagnosis was “moderate to severe squamous dysplasia.” That slide review diagnosis goes on to state “microscopic focus suspicious for superficial invasion.”

Currently there is no ICD-O code for severe squamous dysplasia, however it is unclear if this terminology is equivalent to high grade squamous dysplasia (histology code 8077/2).

Disease History

2018 - Lymphomatoid papulosis (non-reportable)

2020 - Transform to CTCL (and called Mycosis Fungoides specifically) (CTCL/MF same primary)

2021 - Transform to CTCL with large cell transformation

Rule M4 was added to the Other Sites M Rules to address diagnoses of small cell carcinoma following prostate adenocarcinoma, but Rule M4 states the diagnoses must be greater than one year apart.

In this situation, the diagnoses were less than one year apart and one must continue through the M Rules. The next M Rule that applies Rule M18: “Abstract multiple primaries when separate/non-contiguous tumors are on multiple rows in Table 2-21 in the Equivalent Terms and Definitions. Timing is irrelevant.” If one were to STOP at the first rule that applies, one would stop at Rule M18 which confirms the prostatic adenocarcinoma and small cell carcinoma are separate primaries, regardless of timing. If these are not to be accessioned as multiple primaries, does an Exception need to be added to M18?

Per Solid Tumor Manual Other Sites Rule M6, despite the number of areas of involvement, any presentation of Kaposi sarcoma is always a single primary. The primary site is skin using the Kaposi Sarcoma for All Sites Coding Guidelines (Appendix C, 2023 SEER Manual). 

Does SEER Program Coding and Staging Manual Laterality Coding Instruction #4 preclude the use of code 4 [Bilateral involvement at time of diagnosis...] if a patient presents with KS involvement of only both arms or only both sides of the face?

The 10/2023 TURBT final diagnosis is “Urothelial carcinoma with mixed histologic appearances, see synoptic summary below for details.” The synoptic report includes, “Histologic Type Comment: Invasive carcinoma percentages: Micropapillary 60-70%, high grade or poorly differentiated urothelial 20-30%, squamous 10-20%.” The squamous component is stated to be “Urothelial carcinoma with squamous differentiation.”

It appears there are two specific urothelial carcinoma subtypes to consider: Urothelial carcinoma, micropapillary variant (8131/3) and poorly differentiated carcinoma (8020/3). The squamous component would not be considered because there is no specific histology for “squamous differentiation.”

The micropapillary component is the predominant histology (60-70%) in this case, and it does seem like this is important to capture. However, the WHO Blue Book indicates poorly differentiated carcinoma of the bladder has a poor prognosis.

Example:  A prostate core biopsy showed intraductal carcinoma in 09/2022, which is an in situ tumor.  A core biopsy again showed intraductal carcinoma in 12/2022.  The subsequent radical prostatectomy in 04/2023, revealed multiple foci of invasive prostate adenocarcinoma with extensive intraductal carcinoma. 

Per Solid Tumor Rules, Other Sites, Rule M3, acinar adenocarcinoma of the prostate is always a single primary.  Note 4, this rule applies to subtype variants of acinar adenocarcinoma listed in Table 3, which has intraductal/ductal as a variant subtype of acinar adenocarcinoma. Does rule M3 apply to incidence cases (an invasive tumor following an in situ tumor)?