SEER Inquiry System - Search

In addition to the issue mentioned above, there is a SINQ answer that conflicts with the 2018 ICD-O-3 Histology Update table. SINQ 20130134 indicates indolent systemic mastocytosis is reportable for cases diagnosed 2010 and forward. There is no date restriction indicating the SINQ note applies only for cases diagnosed 2010-2017. Since indolent systemic mastocytosis was changed to borderline (9741/1) for diagnosis year 2018+, should the diagnosis year range be updated for this SINQ answer?

Example: Lung resection final diagnosis is Lung adenocarcinoma, see Summary Cancer Data, and the Summary Cancer Data (CAP Synoptic Report) states Histologic type: Invasive adenocarcinoma, solid predominant. Other Subtypes Present: 20% acinar and <5% micropapillary components.

Instruction 1B and Note 1 for Coding Multiple Histologies (Lung Histology Rules) indicates type, subtype, component, and predominantly are all terms that may be used to code the most specific histology. In this case, the multiple specific histologies were documented using all of those terms.

Note 2 for instruction 1B states predominantly describes the greatest amount of tumor and when it is used for the listed subtypes of adenocarcinoma, that subtype should be coded. However, Note 2 does not indicate that the other subtypes are ignored when one is identified to be predominant and the others are identified as subtype or component only.

In Table 3 (Specific Histologies, NOS/ NST, and Subtypes/Variants), the entry for papillary carcinoma, NOS includes a change in column 3 of the 2018 Breast Solid Tumor Rules that conflicts with the H Rules. It is not accounted for in the change log. No explanation is offered as to why this change was made. This is a major change because encapsulated papillary carcinoma is frequently associated with carcinoma NST, and we have not been collecting these as such.

Encapsulated papillary carcinoma (8504) in column 3 now includes an indented entry, with invasive carcinoma, NST/invasive duct carcinoma 8504/3. However, most encapsulated papillary carcinomas are in situ or there is no definitive statement of invasive encapsulated papillary carcinoma, so when in situ and invasive tumors are present, we are instructed to code the invasive histology (which would be the invasive carcinoma (NST), 8500/3). How are registrars to arrive at the correct histology without a new H rule or a clarification regarding this update being documented in the change log?

Does the same change/addition apply to solid papillary carcinoma? These are often also associated with carcinoma, NST. Again, without an explanation regarding the change mentioned above, it is difficult to understand why the change was made.

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

The patient has a history of a minimally invasive endometrial adenocarcinoma that was low grade and confined to an endometrial polyp in 2001. The patient underwent a total abdominal hysterectomy/bilateral salpingo-oophorectomy (TAH/BSO) that entirely removed the tumor at that time.

Almost 18 years later, the patient had a left inguinal mass excision that was, Carcinoma of gynecologic origin, consistent with clear cell carcinoma. No other disease was found, the physician never indicated whether this was felt to be metastatic from the previous, low grade adenocarcinoma or not. It was only noted as, an unusual malignancy of the left lower quadrant and inguinal region of gynecologic origin. No further information was available in the medical record or from the physician on follow-up.

Although neither the Solid Tumor Rules nor the MPH Rules (still in use for the Other Sites schema) apply to metastasis, given the differences in histology and behavior of these two tumors (i.e., minimally invasive, low grade disease diagnosed in 2001 vs. higher grade, more aggressive tumor in 2019) should the current clear cell carcinoma of GYN origin really be the same primary as the 2001 endometrial adenocarcinoma?

Rule H13 states to code the histology to metaplastic carcinoma when there is metaplastic carcinoma (or a subtype/variant) and invasive carcinoma NST. This rule makes no mention of lobular carcinoma. However, in Table 3, Note 2 for metaplastic carcinoma (8575) states metaplastic carcinoma, NOS and subtypes are almost always mixed with invasive mammary carcinoma, NST and at times lobular carcinoma. These tumors should be coded to metaplastic regardless of percent invasive mammary carcinoma or lobular carcinoma present.

While Table 2 (the mixed histology code table) does include an entry for metaplastic carcinoma AND carcinoma NST OR lobular carcinoma, it is unclear why lobular carcinoma has not been added to Rule H13 as well.

If a single tumor has metaplastic plus lobular carcinoma, Rule H13 does not apply and one has to continue through the rules. Unfortunately, the next rule registrars would be tempted to use is Rule H18: Code the histology that comprises greater than 50% of tumor when two histologies are on different rows in Table 3. This Rule does not state it does NOT apply to metaplastic carcinoma (only mucinous). So, if for some reason the lobular was greater than 50%, the incorrect histology would be coded (unless the registrar happened to remember Note 2 in the metaplastic carcinoma entry in Table 3).

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

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.

In the 2018 ICD-O-3 Update Table, undifferentiated high-grade pleomorphic sarcoma and undifferentiated high-grade pleomorphic sarcoma of bone (C40_) were both listed as a New Term for histology 8830/3. There was no site restriction for a diagnosis of undifferentiated high-grade pleomorphic sarcoma. Therefore, it appears the diagnosis could easily be applied to a soft tissue tumor. This histology is used by pathologists in our region for soft tissue tumors as well as bone tumors. However, in the ICD-O-3.2 Table an entry (or synonym) was not provided for a tumor outside the bone.

The ICD-O-3.2 Table only lists undifferentiated high-grade pleomorphic sarcoma of bone for site codes C40_ and C41_ as a synonym for histology 8830/3. This also is not listed in the ICD-O-3.2 Implementation Guidelines. As a result, it is unclear whether a diagnosis of undifferentiated high-grade pleomorphic sarcoma of the soft tissue can be coded to 8830/3 and/or can be a synonym for the preferred term (8830/3, Malignant fibrous histiocytoma). Can a diagnosis of undifferentiated high-grade pleomorphic sarcoma of the soft tissue be coded to 8830/3, C49_ as it was per the 2018 ICD-O-3 Update Table?

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