SEER Inquiry System - Search

The patient had residual tumor following the 2018 transsphenoidal resection and underwent an additional surgery after the residual tumor increased in size. Since pituitary adenoma/pituitary neuroendocrine tumor (PitNET) is a new malignant neoplasm for cases diagnosed 2023 and later, should this be a new primary per M5? Or do we disregard the change in behavior and apply rule M2 (single tumor is a single primary) for this scenario?

March 2022, left shoulder soft tissue mass excision shows a spindle cell tumor with outside consultation diagnosis of malignant neoplasm with neuroectodermal differentiation and TPR-NTRK1 gene rearrangement. Diagnosis comments indicate the findings most closely resemble the spectrum of kinase-rearranged mesenchymal neoplasms, such as lipofibromatosis-like neural tumor. However, the expression of SOX10 and mature melanocytic markers is unusual, and does not exclude melanocytic differentiation.

Should this be classified as a peripheral neuroectodermal tumor (9364) or as an "NTRK-rearranged spindle cell neoplasm (emerging)" (8990) if there is a NTRK gene rearrangement?

Since the peripheral nerves are included in the Malignant CNS schema of the Solid Tumor Rules, neither the differences in subsite nor timing indicate these are separate primaries (Rule M10 indicates a single primary). However, these are separate MPNSTs in different sites and the tumors are not stated to be metastasis. Additionally, these are treated as separate primaries by the managing physician.

While the malignant CNS tumors do not take timing into account, is this correct for these peripheral nerve tumors that are often treated similarly to soft tissue tumors? Should Rule M8 be updated to include tumors in different peripheral nerve subsites?

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?

This patient had serosal involvement and the pathologist and managing physician staged this as pT4a disease. This extension seems best captured by EOD Primary Tumor code 500. Additionally, the patient had discontinuous metastatic involvement of the peritoneum, and this was staged by the pathologist and managing physician as pM1b (Intraperitoneal metastasis only, including peritoneal mucinous deposits containing tumor cells). Although this peritoneal involvement was present in the right lower quadrant, it was staged as distant metastatic disease and not as part of the primary tumor category. However, currently EOD Primary Tumor code 600 would seem to apply since the peritoneal tumor was in the right lower quadrant. Code 600 is defined as mucinous tumors with peritoneal involvement confined within right lower quadrant. This EOD Primary Tumor code and the physician’s M category assignment do not align; the physician has staged this as distant metastasis (M category, not the T category). Should the peritoneal metastasis (even limited to the right lower quadrant) be included in the EOD Mets field and not in the EOD Primary Tumor field? In other words, should the peritoneal involvement included in EOD Primary Tumor code 600 be reclassified in EOD Mets code 30 (Intraperitoneal metastasis (peritoneal carcinomatosis) WITH or WITHOUT peritoneal mucinous deposits containing tumor cells)?

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.

Example: Patient is diagnosed with grade 1 well-differentiated neuroendocrine tumor of the ileum, confirmed on ileocolic resection in 2023. The final diagnosis is a 2.8 cm ileal mass, with focal lymph-vascular invasion and a single 0.6 cm tumor deposit within mesenteric fat; primary tumor completely resected with widely negative margins and 10 regional nodes negative for malignancy.

According to AJCC, mesenteric masses less than 2 cm should be stated in the pathology report as being present and collected by registrars but do not affect stage. EOD Regional Nodes has a code for large mesenteric masses greater than 2 cm only. How should we record these smaller tumor deposits if they are not supposed to affect stage?

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?

While SEER*Rx does indicate infliximab should be coded as biological response modifier (BRM)/Immunotherapy, the manufacturer website for this medication indicates it is given for: Crohn’s disease, ulcerative colitis, rheumatoid arthritis, psoriatic arthritis, ankylosing spondylitis, and plaque psoriasis. In addition, SEER*Rx does not indicate which primary sites this treatment may be given for. If it is indeed cancer directed treatment, can the typical primary sites be added for clarity?

Case example: Patient is diagnosed with colorectal cancer and also has an existing diagnosis of Crohn’s disease; received surgery and FOLFOX6, as well as infliximab. There was no statement of what disease the infliximab was given to treat.