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Report Produced: 02/09/2026 18:27 PM

Report Question ID Question Discussion Answer Year
20240068

Solid Tumor Rules/Histology--Ovary:  How is histology coded for an ovary case with a diagnosis of “high grade papillary serous carcinoma” in 2023? This term is not in the Solid Tumor Rules and ICD-O 3.2 updates. Is “high grade papillary serous carcinoma” equivalent to “high grade serous carcinoma” (8461) or to “papillary serous adenocarcinoma” (8441) with high grade captured only in the Grade fields, or is there another more appropriate code?

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

 2024
20220026

Solid Tumor Rules/Histology--Parotid: How is histology coded for a myoepithelial carcinoma ex-pleomorphic adenoma of the parotid?

Patient has a 2021 left parotidectomy showing myoepithelial carcinoma ex-pleomorphic adenoma.  Is this coded to myoepithelial carcinoma (8982/3) or carcinoma ex-pleomorphic adenoma (8941/3)?  It is unclear how to arrive at the correct histology code using the current Solid Tumor Rules.

Code myoepithelial carcinoma ex pleomorphic adenoma as carcinoma ex pleomorphic adenoma (CXPA) (8941/3) using Head and Neck Solid Tumor Rule H1 as this is a single histology.  The WHO Classification of Head and Neck Tumors, 5th ed., describes CXPA as a rare epithelial and/or myoepithelial malignance arising in association with a primary or recurrent pleomorphic adenoma.  The histologic type of the carcinoma component is usually recorded, in this case, myoepithelial carcinoma.

 2022
20240023

Solid Tumor Rules/Histology--Penis:  Why is warty carcinoma listed in Other Sites, Table 23 (Penis and Scrotum Histologies) as 8051 when the ICD-O-3.2 and SINQ 20200003 indicate the correct histology is 8054 for this neoplasm? See Discussion.

The ICD-O-3.2 indicates histology 8051 only applies to diagnoses of condylomatous carcinoma and warty carcinoma made prior to 2018. For penis cases diagnosed 2018 and later, these neoplasms should be coded as 8054. This is consistent with SINQ 20200003.

However, a new Table was added to the Other Sites schema in the 2024 Solid Tumor Rules update. Table 23 lists “Verrucous carcinoma / carcinoma cuniculatum / Warty carcinoma” as histology 8051. While verrucous carcinoma is still listed under histology 8051 in the ICD-O-3.2, warty carcinoma is not.

Does Table 23 need to be updated? Or is this an error in both the ICD-O-3.2 and SINQ 20200003?

Assign histology code 8054/3 for warty carcinoma. Assign 8051/3 for verrucous carcinoma and carcinoma cuniulatum. 

The WHO Classification of Urinary and Male Genital Tumors, 5th edition (2022) revised the terminology for squamous cell carcinoma groupings from "non-HPV-related" to "HPV-independent" and from "HPV-related to "HPV-associated". Warty carcinoma is defined as a "morphologically distinct HPV-associated verruciform neoplasm that shares histological features with a giant condyloma but has definitive cytological atypia and a malignant infiltrative architecture."  Verrucous carcinoma (including carcinoma cuniculatum) is defined as an HPV-independent squamous cell carcinoma, and is correctly coded to 8051/3.

The 2024 Solid Tumor Rules, Table 23, Penis and Scrotum Histologies will be updated to reflect this revised terminology and coding.

 2024
20230076

Solid Tumor Rules/Histology--Prostate: How is histology coded and what rule applies to a diagnosis of “prostatic adenocarcinoma with neuroendocrine differentiation” with reference to the Comment: Immunohistochemical findings are consistent with amphicrine carcinoma for a patient with no prior androgen-deprivation therapy. See Discussion.

The case in question represents an adenocarcinoma with neuroendocrine differentiation that arises in the absence of androgen-deprivation therapy. A 2023 journal article states, “We show that amphicrine prostate cancer is a unique entity and differs in clinical and molecular features from high-grade neuroendocrine carcinomas of the prostate. Our study highlights the need to recognize AMPC as a unique molecularly defined subgroup of prostate cancer.”

Should we be coding this with histology 8140 (Adenocarcinoma, NOS) because we have no specific code for an amphicrine carcinoma? Should we code this as 8045 (Mixed small cell carcinoma) because this is possibly the only way to capture both the adenocarcinoma and neuroendocrine components in a patient without previous treatment?

Our concern about using histology code 8574 (Adenocarcinoma with neuroendocrine differentiation) is that, while a valid histology code, this might confound the data if researchers are trying to separate the truly treatment-related tumors from other histologies captured under 8574.

Assign 8140/3 (adenocarcinoma, NOS). WHO has not yet recognized the variant amphicrine prostate carcinoma and have not proposed an ICD-O code for this neoplasm. Document information in a related text field.

 2023
20230065

Solid Tumor Rules/Histology--Prostate: Is histology coded as 8045 (Combined small cell carcinoma) for a 2023 diagnosis of two-component carcinoma comprised of both acinar adenocarcinoma and small cell neuroendocrine carcinoma of the prostate? See Discussion.

This patient does not have a previous diagnosis of prostate adenocarcinoma nor a previous history of androgen-deprivation therapy.

Does the logic in the Other Sites Solid Tumor Rules (STRs) noted in SINQ 20200052 still apply? This SINQ confirms a diagnosis of mixed prostatic adenocarcinoma and small cell neuroendocrine carcinoma is 8045. This matches the STRs instructions for Rule H21 and Table 2 (Mixed and Combination Codes), row 1. Row 1 indicates a mixed small cell carcinoma and adenocarcinoma is combined small cell carcinoma (8045). For a patient without previous treatment, is this the correct mixed histology code?

Code histology as combined small cell carcinoma (8045) based on the Other Sites Solid Tumor Rules, May 2023 Update, Table 2, Mixed and Combination Codes, for this mixed histology prostate carcinoma consisting of adenocarcinoma and small cell neuroendocrine carcinoma regardless of treatment status. This is similar to SINQ 20200052 that applies to one tumor with mixed histologies.

 2023
20240010

Solid Tumor Rules/Histology--Prostate: Other Sites Solid Tumor RulesTable 3 (Prostate Histologies), Note 1 in the Adenocarcinoma with neuroendocrine differentiation (8574/3) row, conflicts with Note 2 and requires further clarification. See Discussion.

Note 1 states that this histology is treatment-related neuroendocrine prostatic carcinoma demonstrating complete neuroendocrine differentiation or partial neuroendocrine differentiation with adenocarcinoma after androgen-deprivation therapy (ADT). Conversely, Note 2 says to code 8574/3 only when there is no history of previous prostate adenocarcinoma or history of androgen-deprivation therapy.

The WHO Blue Book does confirm this is a treatment-related histology, so it seems we would only use this for an adenocarcinoma with neuroendocrine differentiation (or even possibly a mixed histology tumor with adenocarcinoma and small cell carcinoma components) if the patient had previous treatment.

If this histology is treatment-related, why would we use this code for a patient without a history of prostate adenocarcinoma or androgen-deprivation therapy? Should Note 2 be corrected?

Does this histology apply to a post-treatment diagnosis of mixed adenocarcinoma and small cell carcinoma? If yes, should this clarification be added?

Answer updated September 2025

Per consultation with a male genital and urinary subject matter expert pathologist, if a patient with a previous diagnosis of acinar adenocarcinoma (or a subtype variant of 8140/3) of the prostate was treated with radiation and/or androgen deprivation therapy (ADT, a form of hormonal therapy), the following subsequent diagnoses are NOT a new primary.

  • Adenocarcinoma with neuroendocrine differentiation (8574/3)
  • Adenosquamous carcinoma (8560/3)
  • Small cell carcinoma (8041/3)
  • Squamous cell carcinoma (8070/3)

For example, a patient is diagnosed with acinar adenocarcinoma and undergoes hormone therapy. Two years later, the patient is diagnosed with adenosquamous carcinoma. The adenosquamous carcinoma should be considered treatment-related and is not a new primary.

 2024
20240013

Solid Tumor Rules/Histology--Testis: Can a definition for "teratoma with somatic-type malignancy" (9084) be added to the Other Sites Solid Tumor Rules? See Discussion.

We included this histology in SEER Workshop Case 12 and the histology coding accuracy was less than 40%. From emails we received, it is clear that registrars are unaware that the "somatic type malignancy" can vary but code 9084 applies when the diagnosis is teratoma WITH any non-germ cell tumor component. It may be helpful to add a definition for "teratoma with somatic-type malignancy" (9084) to the Solid Tumor Manual.

We will add the same definition for teratoma with malignant transformation found in the ovary table: 9084/3 Teratoma with malignant transformation when a malignant (/3) histology arises in a benign teratoma.

Teratoma with malignant transformation and teratoma with somatic-type malignancy are synonoyms. The term teratoma with somatic-type malignancy is outdated and no longer recommended.

 2024
20230068

Solid Tumor Rules/Histology--Thyroid: What is the histology code for a diagnosis of poorly differentiated thyroid carcinoma arising in a background of solid papillary thyroid carcinoma? See Discussion.

Patient had a hemithyroidectomy with the final diagnosis above. There does not appear to be an Other Sites H rule or table that addresses this combination of histologies for thyroid primaries.

Code to poorly differentiated thyroid carcinoma, 8337/3.

In this case the tumor is comrpised of two difffernat thyroid histologies: poorly differentiated carcinoma 8337/3 and papillary thyroid carcinoma 8260/3. WHO does not have a code for this combination. Per our endocrine pathology expert, the poorly differentiated carcinoma is the more agressive histology and will determine treatment and progrnosis.

 2023
20220019

Solid Tumor Rules/Histology--Thyroid:  What is the correct histology code for a papillary carcinoma, encapsulated with columnar cell features?  See Discussion.

There is an ICD-O histology code for papillary carcinoma, columnar cell (8344/3) as well as papillary carcinoma, encapsulated (8343/3). Per Rule H13, the terms “with features of” may be used to identify a subtype.

Considering these two subtypes, and knowing there is no specific histology code for this combination, is the first rule that applies H17 (code the numerically higher histology code)?

Code to papillary carcinoma, encapsulated (C73.9) (8343/3) using Solid Tumor Rules, Other Sites, Rule H11, code the histology when only one histologic type is identified.  The usage of features is describing the cellular architecture of the encapsulated papillary carcinoma and does not necessarily indicate a specific histologic type. We consulted with our endocrine specialist pathologist who agrees and indicated terminology used in thryoid neoplasms is inconsistent.

 2022
20220018

Solid Tumor Rules/Histology--Thyroid:  What is the correct histology code for the following thyroid primary with multiple tumors abstracted as one primary diagnosed prior to 2021?  See Discussion.

2016 Total thyroidectomy, Multifocal

-Dominant Tumor:  Right Lobe, Papillary thyroid carcinoma (8260/3)

-Tumors two through five:  Three tumors Papillary thyroid carcinoma (8260/3), and one tumor Papillary thyroid carcinoma, follicular variant (8340/3)

-An additional tumor: Non-invasive follicular thyroid neoplasm with papillary-like nuclear features (8343/2)

Code this multifocal thyroid carcinoma, single primary, as papillary thyroid carcinoma, follicular variant (8340/3) using Solid Tumor Rules, Other Sites, Rule H13 that says to code the most specific histologic term. We consulted with our endocrine specialty pathologist and when there is a mix of papillary and follicular variants, assign 8340.

Non-invasive follicular thyroid neoplasm with papillary-like nuclear features is coded as 8349/1 beginning in 2021.  According to the WHO Classification of Endocrine Organs, 4th edition, it was formerly classified as non-invasive encapsulated follicular variant of PTC (FVPTC) (8343/2) but was reclassified based on extremely low malignant potential.

 2022