SEER Inquiry System - Search

Assign code 8461/3 for high-grade papillary serous carcinoma.

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

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.

Assign histology code 8815/3 per ICD-O-3.2. Sinonasal glomangiopericytoma is also referred to as a sinonasal hemangiopericytoma. Prior to 2021, it was coded as 9150/3.

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 this case as a single primary. Code as 8044/3 (small cell carcinoma, hypercalcemic type) listed in the Other Sites Solid Tumor Rules, Table 13. Small cell carcinoma, large cell variant, is a subtype of small cell carcinoma, hypercalcemic type. This table does not include all possible histologies.

WHO Classification of Female Genital Tumors, 5th edition, states: Small cell carcinoma of the ovary, hypercalcemic type, is rare, accounting for < 1% of ovarian tumors. Small cell carcinomas, hypercalcemic type, are usually large, with a mean size of 15 cm (range: 6–26 cm). Large cells are present (in varying numbers) in half of these tumors, which are designated “small cell carcinoma, large cell subtype” if the large cells are predominant (which is rare).

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.

Change to current instructions. We will update this example in the next edition of the manual. The new example will instruct registrars to look for other descriptions of the patient’s race. When no other information is available, assign 07, Native Hawaiian, in Race 1 and assign 97, Pacific Islander, NOS in Race 2. Begin following this new instruction now.

Code Primary Site to C480 (retroperitoneum). 

Endometrial tissue may "break away” from the uterus and implant throughout the pelvic and abdominal cavities. This can occur in patients who suffer from endometriosis. This tissue remains behind when surgical removal of the uterus is done. Common sites of implantation are colon, peritoneum, retroperitoneum, and bladder. These cells may become malignant. When the uterus is no longer present (patient had surgical removal), code the site where the carcinoma was identified.

The site-morphology combination of C480 and 8380/3 was designated as an unlikely site-morphology combination by the Cancer PathCHART expert pathologist review, as this is a rare type of tumor. Assign a value of 1 in the Over-ride Site/Type [2030] data item in order to pass the Primary Site, Morphology-Type, Beh ICDO3, 2024 (SEER) edit.

The example used in Rule M15 of the Urinary Solid Tumor Rules should refer to Table 2. We will update this in the next revision of the Rules.