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Code as an oropharyngeal primary site and histology as solitary plasmacytoma (9734/3) based on consultation with our hematological expert.

The WHO Classification of Hematopoietic and Lymphoid Tissues defines multiple myeloma as "bone marrow plasma cell percentage >60%." There are several other factors, but the bone marrow involvement is the key point for your case. The pathologist also states that the bone marrow is consistent with "plasma cell neoplasm," which by itself is not the same as multiple myeloma.

This case has 5-10% involvement by plasma cell neoplasm. This does not meet the bone marrow qualifications for multiple myeloma and is consistent with the pathologist's statement that there is minimal bone marrow involvement.

We will be updating the Hematopoietic and Lymphoid Neoplasms Database and Manual to clarify this (2025 updates).

Abstract two separate primaries, ET (9962/3) and primary myelofibrosis (9961/3) using the current Hematopoietic and Lymphoid Neoplasms (Heme) Manual and Database (DB), Rule M15, use the Heme DB Multiple Primaries Calculator. Also refer to the example in Rule M15. In 1998, though the ET was not reportable (9962/1), the patient was treated with chemotherapy as a malignant neoplasm (9962/3). The Calculator instructs us to code separate primaries for these two histologies.

ET may evolve into a secondary myelofibrosis, also known as post-essential thrombocythemia-myelofibrosis (post-ET MF). The diagnosis must be stated as post-ET MF; this would be a single primary.

Abstract two primaries using Urinary Solid Tumor Rules, Rule M12. The histologies include non-invasive papillary urothelial carcinoma (8130/2) and non-invasive micropapillary urothelial carcinoma (8131/3). The two histology codes are listed as subtypes of Papillary urothelial (transitional cell) carcinoma in column 3 of Table 2.

WHO Classification of Urinary and Male Genital Tumors, 5th edition classifies micropapillary urothelial carcinoma as an aggressive subtype of urothelial carcinoma with carcinoma in situ present in more than half of all micropapillary carcinomas.

Rule 7 Note 3 of the Urinary Solid Tumor Rules states that there are no /2 subtypes for urothelial carcinoma with the exception of papillary urothelial carcinoma and applies to multiple occurrences of /2 urothelial carcinoma of the bladder.

Rule 8 applies to 8131/3 and 8120/3.

Please understand that AJCC sets the standards for TNM Staging and the Cancer PathCHART (CPC) initiative sets standards for the validity of site and morphology combinations. The statement in the AJCC manual “8240 and 8249 are excluded for topography code C160” means that these two histologies are not staged using the AJCC Staging System. As with numerous other reportable entities that are not staged by AJCC, the case is reportable and a Summary Stage should be assigned. Combinations of C160 with 8240 or 8249 are valid site/histology combinations for registry reporting and should not be discouraged from use if they correspond to the pathologist’s diagnosis. This goes for any other similar note in the AJCC manual. All CPC standards are enforced via the Primary Site, Morphology-Type, Beh ICDO3, 2024 (SEER) N7040 and Histologic Type ICDO3, Primary Site, Date of Diagnosis (NAACCR) N4911 data quality edits. Registrars can also look up the validity of site and morphology combinations using the CPC*Search tool:  https://seer.cancer.gov/cancerpathchart/search/tool/. 

It is important to remember the following.

• ALWAYS code the tumor histology stated by the pathologist/physician
• NEVER change the tumor histology to assign TNM
• Not all tumors or histologies can be staged per TNM
• Cases that cannot be assigned TNM are assigned a summary stage

High grade dysplasia of the esophagus is reportable. The example will be corrected in the next edition of the SEER manual.

Lymphoepithelial carcinoma is a subtype of SCC usually seen in skin or H&N sites and often associated with EBV. CPC SME review determined 8082/3 invalid for breast but did not recommend a substitute code. There were only 45 cases coded 8082 2001 to 2019. For this case, it's possible the lesion originated in the breast skin and progressed to breast tissue. SCC is a subtype of metaplastic breast carcinoma so one could argue it code be coded either 8575 or 8070. For this case, we recommend assigning 8500/3. Use text fields to record the details.

Do not code Reblozyl (luspatercept) as treatment. Luspatercept is an ancillary drug approved to treat anemia associated with MDS but not the malignancy.

Assign code 550 (Bladder, NOS excluding mucosa) to EOD Primary Site based on invasion into the bladder with no mention of mucosa. EOD Primary Tumor for cervix, Note 1, instructions are to use the extension information to code primary tumor in preference to a statement of FIGO stage when both are available. TNM staging is closely related to FIGO stage, and the surgical findings of bladder invasion NOS in this case should be used in preference to the statement of T4.

Report malignant spindle cell neoplasms consistent with atypical fibroxanthoma as directed by Appendix E.1 of the 2023 and 2024 versions of the SEER Manual using 8830/3 (fibroxanthoma, malignant).

We will update the answer in SINQ 20190102.  While the Other Sites Solid Tumor Rules address coding an NOS and specific histology sub-type/variant, this situation is not specifically addressed. We will also review the rules.

The correct term is diffuse leptomeningeal glioneuronal tumor listed as a synonym in Column 2. 

We will add the term diffuse in Note 2, Column 1 with the 2025 updates. In the meantime, you can add "diffuse" to your pdf version until the update is published.