SEER Inquiry System - Search

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.

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.

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).

If you cannot clarify this with the involved physicians, do not report this case of meningioma based on information provided. There is no indication that the patient was treated or further evaluated for meningioma.

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.

Many of these terms are not specified in the codes and definitions in ICD-10-CM. This is because ICD-10-CM does not have the same granularity as ICD-O-3.2. There are a few sites where intraepithelial neoplasia II and/or III are mentioned.

Even though ICD-O-3.2 classifies these as /2 (in-situ), for the intraepithelial neoplasia that are listed in ICD-10-CM, Grade II is designated as benign, while Grade III is designated as in-situ. It is not clear if medical coding will change the Grade II to an in-situ code.

All the in-situ codes (except cervix) are included in the casefinding list. Grade III is included with the in-situ codes; however, there is no guarantee that medical coders will code them as in situ. High grades are coded as in-situ in ICD-10-CM.

For those where there is no specific intraepithelial neoplasia code, the benign codes will cover any benign lesion for that site. This would make for a lot of review using the codes for casefinding. Most of the benign codes were removed from the casefinding list a couple of years ago to make it more manageable. 

Use the casefinding list as a guide for these neoplasias. It is not the most definitive source due to the lack of specificity of ICD-10-CM. It is not possible to map every single histology to a specific code. It is also not known how medical coders across the U.S. are coding these neoplasias. For that reason, pathology should remain the foremost casefinding resource used.

The casefinding team will need to review the prepared list below and determine what codes to add. Any updates will be incorporated in the FY2025 updates (October 2024.)

Report optic nerve sheath meningioma arising in the intraorbital segment. The optic nerve contains four segments, of which intraorbital is one. The WHO Classification of Eye Tumors, 4th edition, defines meningioma as a neoplasm originating from the meningothelial cells of the optic nerve leptomeninges. According to the Table 3 of the Non-malignant Solid Tumor Rules, all portions of the optic are reportable and meningiomas arising in the dura/meninges of an intracranial nerve are coded to cerebral meninges C700.

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.

Assign 8249/3 for high-grade neuroendocrine tumor of the lung.

WHO Classification of Thoracic Tumors, 5th edition, defines two subtypes of neuroendocrine tumor of the lung, typical carcinoids (8240/3), and atypical carcinoids. WHO assigns typical carcinoid/neuroendocrine tumor grade 1 as 8240/3 and atypical carcinoid/neuroendocrine tumor grade 2 as 8249/3. They are regarded as low-grade and intermediate-grade, respectively. The preferred term for 8249/3 in ICD-O-3.2 is neuroendocrine tumor grade 2, with neuroendocrine tumor grade 3 as a related term. The Lung Solid Tumor Rules assign atypical carcinoid as 8249/3.

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.