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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.

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.

The AJCC 8th edition confirms that the identification of psammomatous calcifications within a cervical lymph node is metastatic disease.

Example: Patient had a thyroid lobectomy and level VI neck node excision in August 2022. The final diagnosis is multifocal papillary carcinoma of the thyroid, as well as rare psammomatous calcifications only in the resected node. The pathologist notes that “psammoma bodies only” in lymph nodes is not well defined, and while indolent, they do indicate capacity for lymphatic spread and are pN1a.

Should thyroid primaries with cervical node psammomatous calcifications get captured in EOD Regional Nodes category as it is in the AJCC pN staging?

Historically, multiple invasive ductal and lobular carcinomas diagnosed within 5 years were abstracted as a single primary. However, it is not clear if Rule M10 or M14 applies to this situation per the 2023 Solid Tumor Rules updates.

Rule M10 addresses multiple tumors of carcinoma of no special type (NST)/duct and lobular, but there is no timing criteria mentioned. Does M10 apply to cases diagnosed synchronously, or metachronously, or at least within 5 years? Should Rule M10 include a Note instructing registrars to accession a single primary for the scenario in question?

If timing matters for Rule M10, then the next rule that applies is M14. Rule M14 instructs one to abstract multiple primaries when separate/non-contiguous tumors are on different rows in Table 3, and carcinoma NST/duct and lobular carcinoma are on separate rows in Table 3.

Patient was diagnosed in September 2022 via excision of a 12 cm pelvic mass with final diagnosis of Myofibroblastoma with sarcomatous transformation.

Diagnosis comment states, “Most of the tumor is composed of conventional features of myofibroblastoma. However, a focal area demonstrates increased cellularity, fascicular growth and increased mitotic activity (up to 11 per 10 hpf), consistent with sarcomatous transformation (morphologically low to intermediate grade).”

Is this sarcomatous transformation describing a malignant transformation from an otherwise benign histology? If so, how should histology be coded in this case?

Table 19: Vulva Histologies of the Other Sites Solid Tumor Rules does not include entries for either keratinizing or nonkeratinizing squamous cell carcinoma in the “Squamous cell carcinoma, NOS” row. However, these are two distinctly different histologies per the ICD-O-3.2.

All other Solid Tumor Rules schemas include an M Rule instructing one to abstract multiple primaries when separate/non-contiguous tumors are two or more different subtypes/variants in Column 3 of the Specific Histologies, NOS, and Subtype/Variants Table for the schema (e.g., Rule M6 for Lung). The timing of these tumors is stated to be irrelevant. The Notes confirm the tumors may be subtypes/variants of the same or different NOS histologies and tumors in column 3 are all distinctly different histologies (even if they are in the same row). However, the 2023 Other Sites schema appears to be missing this rule.

Should these distinctly different histologies be accessioned as separate primaries? Is an M Rule missing from the Other Sites schema to address distinctly different histologies?

There was a 3.5 cm invasive adenocarcinoma tumor in the pancreatic head. There were four separate, sized pancreatic neuroendocrine tumors measuring 0.9, 0.7, 0.5 and 0.2 cm in the pancreatic body. There are multiple tumors with distinctly different histologies. However, Table 11 (Pancreas Histologies) does not include any entries for neuroendocrine tumors of the pancreas (e.g., pancreatic NET, WHO grade 1, histology 8240). While it would seem Rule M19 should apply as they’re distinctly different histologies, because PanNETs are not included in Table 11, it is not clear which M Rule applies to these multiple tumors.

If Rule M19 does not apply, we are left with Rule M21 (Abstract a single primary when there are multiple tumors that do not meet any of the above criteria). Are these separate tumors with distinctly different histologies really a single primary? Pancreatic neuroendocrine tumors are not an uncommon histology, is there a reason these were not included in Table 11?

An argument could be made to apply Rule M10 (timing rule which may result in reporting the case as an additional primary) because the 2022 primary included multiple non-invasive urothelial carcinoma tumors in both the bladder and other urinary sites (coded to site C689, not C679) following a long disease-free interval. While Rule M10 excludes multiple bladder tumors, does that also apply when new, multifocal urothelial tumors arise in both bladder and other urinary sites? Does the presence of any subsequent bladder tumor rule out the use of M10 and one must use M11 that indicates reporting this disease process is a single primary?