SEER Inquiry System - Search

The 2021 ICD-O-3.2 Update includes papillary microcarcinoma (8341/3) as the preferred term for thyroid primaries (C739). However, there are multiple SINQ entries instructing registrars not to use code 8341/3 for diagnoses of micropapillary carcinoma of the thyroid (including SINQ 20071076, 20081127, 20110027, 20150023, and 20180008).

SINQ 20150023 specifically indicates: Per the WHO Tumors of Endocrine Organs, for thyroid primaries/cancer only, the term micropapillary does not refer to a specific histologic type. It means that the papillary portion of the tumor is minimal or occult (1 cm or less in diameter) and was found incidentally. WHO does not recognize the code 8341 and classifies papillary microcarcinoma of the thyroid as a variant of papillary thyroid carcinoma and codes histology to 8260. If the primary is thyroid and the pathology states papillary microcarcinoma or micropapillary carcinoma, code 8260 is correct.

Does this clarification apply to cases diagnosed 2021 and later? If WHO feels the term micropapillary still does not refer to a specific histologic type for the thyroid, why is 8341/3 listed as a preferred term for this morphology/site combination? For cases 2021 and later, should a diagnosis of Incidental papillary thyroid microcarcinoma (3 mm) in left lower pole, be coded as 8341/3 per the ICD-O-3.2, or as 8260/3 per clarification in multiple SINQ entries?

This question was prompted from preparing SEER*Educate coding exercises. We will use the answer as a reference in the rationales.

We think this should be a single primary because the Solid Tumor rules do not apply to metastases. However, we are not sure whether or not the instructions outlined for prostate (SINQ 20180088, 20130221), that indicate we are to accession a new metastatic tumor only with a small cell neuroendocrine histology after an adenocarcinoma, also applies to lung primaries.

We are aware of a phenomenon in which lung adenocarcinoma cases treated with Erlotinib can transform to small cell, but do not know whether it impacts the number of reportable primaries.

The Hematopoietic and Lymphoid Neoplasms Database (Heme DB) definition for systemic mastocytosis with an associated hematological neoplasm (SM-AHN, 9741/3) states SM-AHN is a variant of systemic mastocytosis that arises with a myeloid disease of non-mast cell lineage (e.g., MDS, MPN, etc.) and that,

However, SINQ 20130172 conflicts with the Heme DB stating the systemic mastocytosis and the associated hematological neoplasm are a single primary coded to a single histology (9741/3) per Rule M2.

2020 Diagnosis: Patient had a right hemicolectomy showing adenocarcinoma of cecum, tumor extends into proximal portion of attached vermiform appendix. Tumor invades through muscularis propria into pericolorectal tissues (NOS). Regional lymph nodes: 06/39. Primary Tumor EOD: Where does the appendix involvement come into coding or will this be based on the pericolorectal tissue (NOS) invasion? What is my Summary Stage? I know it is at least 3 due to regional ln involvement, but the appendix involvement is making me question 3 vs 4.

Example: Patient is found to have a 9.4 cm GIST in the jejunum and 2 cm GIST in the stomach during resection, neither stated to be outright malignant. Similar to the instruction in SINQ 20190041, this case is coded as a malignant jejunal primary due to multifocal tumor. However, it is unclear how to account for the stomach tumor, or any other multifocal tumor for GIST, when coding EOD and Summary Stage.

CT a/p read by radiologist shows: "Bosniak 4 cystic lesion of right kidney." Follow-up MRI a month later reads "right kidney cystic lesion with enhancing mural nodule concerning for cystic renal cell carcinoma (RCC)." Urologist consult used the same wording of "Bosniak 4 cystic lesion" and "concerning for renal cell carcinoma." Treatment discussed but due to patient health status recommended repeat imaging. Repeat CT few months later reads: "cystic right renal lesion with enhancing nodule similar to most recent prior and suspicious for cystic RCC."

Though "suspicious for cystic RCC" per latest imaging is reportable, Bosniak 4 is "clearly malignancy, ~100% malignant" by definition, so is the case actually reportable with the first CT a/p date as date of diagnosis?

Table 4 (Changes in reportable terminology), 2021 ICD-O-3.2 Update, does confirm that the term malignant no longer needs to be used to describe a paraganglioma, but Table 4 includes the histology for extra-adrenal paraganglioma, NOS (8693/3) as the new preferred term for paraganglioma. Paraganglioma, NOS is histology code 8680/3. Which code is correct?

This question was prompted from preparing SEER*Educate coding exercises. We will use the answer as a reference in the rationales.

While we recognize the Heme DB has been the correct source for histology coding for heme and lymphoid neoplasms dating back to 2010, the ICD-O-3.2 Implementation Guidelines appear to provide incorrect coding instructions. Histologies 9670/3, 9728/3, 9729/3 and 9836/3 are listed in Table 3 - Deleted ICD-O codes in ICD-O-3.2.

While we recognize these histologies have been included in this Table because they have now been deleted, it is unclear whether the Comments regarding their use listed in the 4th column of the Table is correct. For each of these histologies, the comment states the histology listed in the 1st column (ICD-O-3/3.1) should be used prior to 2021. For example, for histology 9670/3, the comment states: Cases diagnosed prior to 1/1/2021 use code 9670/3. Cases diagnosed 1/1/2021 forward use code 9823/3. However, each of these histology codes have been obsolete for cases diagnosed 1/1/2010 and later. If registrars were following the Heme DB and Heme Manual instructions (the appropriate coding source for these neoplasms), these histologies would not have been used in a decade.

Should the Comments column in Table 3 be updated? Or should a Note follow the Table indicating registrars should not use these histology codes for cases diagnosed after 1/1/2010, and these histology codes have been deleted for cases diagnosed 1/1/2021? It seems misleading to indicate any of these are valid histology codes for a 2010-2020 diagnosis when the Heme DB confirms these histology codes only apply to cases diagnosed prior to 2010.