SEER Inquiry System - Search

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.

Assign Primary Site code C504 based on the location in the upper outer quadrant of the right breast, 10 o’clock, as opposed to code C501, around the areolar complex. The 2024 SEER Manual Breast Coding Guidelines advise that C502 - C505 are generally preferred over C501 when there is no other way to determine the subsite.

Sites may be added to certain combinations when indicated by ClinCORE review for Cancer PathCHART. Please note some sites were added in the 2024 update as a result of PathCHART review. A newly-formed Solid Tumor Editorial Board and its subgroups are currently working to evaluate the Solid Tumor Manual and make recommendations on ways to improve the structure and formatting of the manual and its content.

Follow the rules and instructions in the Other Sites STRs when assigning combination histology codes.

Histology Coding Rules

Use the Histology Coding Rules when assigning combination codes.

Coding Histology Information

Use this section that includes the mixed histology (Table 2) and site-specific histology tables (Tables 3-23) for one or more histologies within a single tumor. Do not use this section in place of the Histology Coding Rules.

While site-specific histology tables, based on current WHO Classification of Tumors books, have been added to Other Sites STRs, not all site groups have individual histology tables; coding may require the use of ICD-O and updates. The histology tables in Other Sites STRs include additional coding instructions and notes to assign the correct ICD-O code when appropriate.

The tables are not meant to be all-inclusive; rather they are intended to address difficult coding situations to facilitate the assignment of the correct histology code.

Table 2: Mixed and Combination Codes Instructions

Once you have identified the histology terms and have been instructed to use Table 2 by the Histology Coding Rules, compare the terms in the diagnosis to the terms in Column 1. When the terms match, use the combination code listed in Column 2. Use adenocarcinoma mixed subtypes 8255 as a “last resort” code.

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.

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).

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.

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

Determine whether the lesion is on the mucosa or skin based on the pathology report, history and physical, and operative notes when available. The gross description of the pathology report should include information to help in determining whether the site of origin is epithelium (skin) or mucosa (lip).

Do not report the case when the site of origin cannot be determined between a reportable site and non-reportable site for this histology. This includes situations where the site of origin or the site with the greatest involvement is undetermined. In this case, you cannot confirm reportability.

Assign 8013/3 (combined large cell neuroendocrine carcinoma). There are two histologies present: large cell NEC and urothelial. Literature search found primary large cell NEC of the bladder is extremely rare with less than 20 reported cases. This case does not fall into the site-specific rules and given it's raity, a specific rule for this situation was not and will not be added to the Bladder rules. See #1, Example 2, in the general instructions for coding histology.

Report VIN II. The 2024 SEER Manual lists this as a separate diagnosis in the Reportability section under Malignant Histologies 1.a.x.