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Report Produced: 01/28/2023 01:17 AM

Report Question ID Question (Ascending) Discussion Answer

2018 Solid Tumor Rules/Histology--Colon: What is the histology code of a diagnosis of well differentiated neuroendocrine tumor (NET), grade 2 of the appendix? See Discussion.

SINQ 20160023 and the Solid Tumor Rules indicate NET G1 (or well differentiated NET) is coded as 8240 and NET G2 is coded as 8249.

Clarification regarding grade coding in the CAnswer Forum indicates well differentiated neuroendocrine tumor refers to the histologic type, and not the grade. Therefore, the term well differentiated is ignored for the purpose of grade coding.

Neither of these sources clarifies how to code histology for a tumor diagnosed as well differentiated neuroendocrine tumor, grade 2.

Assign histology code 8249 for histology described as well differentiated NET G2. A synonym for NET of the appendix includes well-differentiated endocrine tumor/carcinoma according to WHO Classification of Tumors of the Digestive System, 4th edition. "Well differentiated" could apply to either NET G1 or NET G2.


2018 Solid Tumor Rules/Histology--Lung: What is the appropriate histology code for the case below in the Discussion section? Is there a difference between adenocarcinoma in situ (bronchioloalveolar carcinoma), non-mucinous type (8252/2) and adenocarcinoma in-situ, mucinous? See Discussion.

Procedure: Wedge, resection specimen, Laterality: Right, Tumor site: Right upper lobe, Tumor size: 1.0 cm in greatest dimension, Histologic type: Adenocarcinoma in-situ, mucinous, Histologic grade: N/A, Visceral pleura invasion: Not identified, Tumor extension: N/A, Margins: Uninvolved, Lymphocytosis.

Assign 8253/2 for adenocarcinoma in situ, mucinous. New codes were added in 2018 for mucinous adenocarcinoma in situ for lung cancer only as all cases were not invasive. Pathologist are discouraged from using the term BAC. In-situ lung tumors can now be identified as either mucinous or non-mucinous and the appropriate ICD-O code should be assigned based on diagnosis.


2018 Solid Tumor Rules/Multiple Primaries--Breast: How many primaries should be reported when a left breast simple mastectomy identifies focal Paget disease of the nipple and 12 axillary nodes positive for metastatic lobular carcinoma (no primary lobular breast tumor identified)?

Abstract two primaries, one lobular carcinoma (8520/3) and another one Paget disease of the breast (8540/3) using the 2018 Breast Solid Tumor Rules, Rule M9: Abstract multiple primaries when the diagnosis is Paget disease with underlying tumor which is NOT duct. Example: Paget disease of the nipple with underlying lobular carcinoma are multiple primaries. Additionally, Table 2, Histology Combination Codes, Note 2 states: Lobular carcinoma and Paget are separate primaries (see Lobular carcinoma and any histology in Table 3 with exception of duct carcinoma/carcinoma NST/DCIS (and subtypes/variants) 8500 and Paget disease, in situ and invasive).

While not identified in the pathology of the mastectomy, the lobular carcinoma is likely underlying as it was identified in the axillary lymph nodes. The 2021 SEER Manual states: If the only pathologic specimen is from a metastatic site, code the appropriate histology code and the malignant behavior code (/3). The primary site and its metastatic site(s) have the same histology.


2018 Solid Tumor Rules/Multiple primaries--Lung: What is the histology and number of primaries for a lung case diagnosed in 2018 with adenocarcinoma with acinar predominant pattern on biopsy, and subsequent lobectomy showing adenocarcinoma with solid growth pattern and separate adenocarcinoma with lepidic predominant pattern? Should this be coded as one primary with an adenocarcinoma, NOS (8140/3) histology since we cannot use pattern or predominant, based on the histologic type listed in the synoptic report, and the fact it states synchronous primary tumors in the same lobe. See Discussion.

02/18 RUL biopsy: Moderatley differentiated adenocacarcinoma with acinar predominant pattern

04/18 RUL lobectomy: 6.5cm poorly differentiated adenocarcinoma with solid growth pattern and 1.1 cm separate adenocarcinoma with lepidic predominant pattern

Synoptic report:

Procedure: Lobectomy

Specimen Laterality: Right Tumor

Tumor Site: Upper lobe

Histologic Type: Invasive adenocarcinoma, solid predominant

Tumor Size: 6.5 Centimeters (cm)

Tumor Focality: Synchronous primary tumors in same lobe

Lymph Nodes Number of Lymph Nodes Involved: 0

Number of Lymph Nodes Examined: 12

Nodal Stations Examined: 4R: Lower paratracheal; 8R: Para-esophageal (below carina); 10R: Hilar; 7: Subcarinal

Pathologic Stage Classification (pTNM, AJCC 8th Edition)

Primary Tumor (pT): pT3

Regional Lymph Nodes (pN): pN0

This is a single primary per Lung rule M7. First determine the histology for each tumor. Both tumors are coded 8140/3 because the histologies are a PATTERN. Reference: Coding Multiple Histologies (precedes histology rules) Instruction 2 says do not code pattern . If the word pattern was not in the diagnosis, you would code the specific histology.


2021 SEER Manual/Surgery of Primary Site--Lung: What is the correct surgery code for a left upper lobe (LUL) wedge resection (confirming adenocarcinoma) followed by a lingular-sparing LUL lobectomy and mediastinal lymph node dissection? Is the correct Surgery Code 22 since the lingula was not resected (not the whole LUL Lung)? Or should the appropriate surgery code be 33 (this surgery suffices to code to a lobectomy with the mediastinal lymph node dissection)?

Assign code 22 for LUL wedge resection followed by a lingular-sparing LUL lobectomy and mediastinal lymph node dissection.  Code the lymph node surgery in Scope of Regional Lymph Node Surgery. We obtained input from an expert who agrees with this code. He states a lingula-sparing lobectomy is best coded as a segmentectomy because it is the same as an apical trisegmentectomy.


Ambiguous Terminology/Histology--Heme & Lymphoid Neoplasms: How are the histology and diagnostic confirmation to be coded when the pathology report's final diagnosis is "plasma cell dyscrasia consistent with plasma cell myeloma" and the physician subsequently states this diagnosis was plasma cell myeloma? See Discussion.


Pathologists often use the diagnosis "plasma cell dyscrasia" followed by an ambiguous term such as "consistent with" or "favors" with a more specific histology such as "plasma cell myeloma." Per initial training for Hematopoietic, ambiguous terminology is not used to code the histology for Heme & Lymphoid Neoplasms. Should the histology be coded as plasma cell dyscrasia (which is not found in the Heme DB or Manual) because the pathology report uses ambiguous terminology to describe the plasma cell myeloma?

If the physician subsequently states the diagnosis is "plasma cell myeloma" in a note following the pathology, should the histology be coded as plasma cell myeloma based on that diagnosis as there was no ambiguous terminology used?

How is the diagnostic confirmation coded for this case? Should this be considered a positive histology diagnosis (diagnostic confirmation code 1) if the pathology diagnosis uses ambiguous terminology only?

For cases diagnosed 2010 and forward, access the Hematopoietic Database at

The histology is coded as Plasma cell myeloma [9732/3]. The diagnostic confirmation is coded to 1 [positive histology].

Under the Definitive Diagnostic Methods section in the Heme DB it indicates that a bone marrow aspiration and bone marrow biopsy are procedures used to diagnose this disease process. This patient's diagnosis was based on the pathology (presumably from a bone marrow biopsy).

NOTE: This is a reportable case. Ambiguous terminology is used to accession cases (determine reportability) because it has been used for over 30 years to do so. Any deviation from using ambiguous terminology to determine case reportability would cause the reporting of incidence counts to vary. In this case, there was a reportable, ambiguous terminology diagnosis of plasma cell myeloma on the pathology report; as well as a reportable physician's statement/diagnosis of plasma cell myeloma.

Ambiguous terminology, however, is not used to report a more specific diagnosis for the Heme & Lymphoid neoplasms. For example, if the pathology report final diagnosis was "Myeloproliferative neoplasm, probably Polycythemia Vera" the histology would be coded as myeloproliferative neoplasm, unclassifiable [9975/3]. The ambiguous terminology indicates that the genetic testing, immunophenotyping, etc., probably are not complete or are not diagnostic of the more specific disease. Wait to code the histology until there is a definite diagnosis given.

SEER*Educate provides training on how to use the Heme Manual and DB. If you are unsure how to arrive at the answer in this SINQ question, refer to SEER*Educate to practice coding hematopoietic and lymphoid neoplasms. Review the step-by-step instructions provided for each case scenario to learn how to use the application and manual to arrive at the answer provided.


Behavior--Breast: Is behavior for encapsulated papillary carcinoma (EPC) of the breast coded as noninvasive or invasive?

The pathologist has the final say on behavior. Code behavior based on the pathologist's final diagnosis. See Rule F in ICD-O-3.

According the WHO Classification of Breast Tumors, encapsulated papillary carcinoma of the breast is in situ, /2. Encapsulated papillary carcinoma with invasion is assigned /3. WHO describes "frank invasive carcinoma" for this histology as "neoplastic epithelial elements infiltrate beyond the fibrous capsule of encapsulated papillary carcinomas." WHO cautions that true infiltration should be "differentiated from entrapment of neoplastic epithelial cells in the fibrous capsule and from epithelial displacement into the biopsy site, which is frequently encountered following needle-core procedures of papillary lesions."


Behavior--Breast: Should the behavior change to /3, invasive, to get a case to clear edits? The histology of this breast case is ductal carcinoma in situ (DCIS), 8500/2. Lymph nodes are positive for micro-mets (0.2 mm-2 mm). SEER Summary Stage: 3, regional lymph nodes positive. This creates an edit for SEER Summary Stage due to the behavior code of /2, in situ.

Code the behavior to /3, not just to pass edits, but because this is an invasive case based on the positive lymph nodes.

For most cases, behavior is based on the primary tumor, but in situations like this where an invasive component cannot be found and there are positive lymph nodes, the /3 behavior is assigned based on the positive lymph nodes.


Behavior--Breast: What is the behavior of a solid papillary carcinoma when a pathologist does not indicate it in the pathology report and follow-up with the pathologist to obtain clarification regarding the behavior is not possible? See Discussion.

Example: Mastectomy specimen final diagnosis shows two foci of invasive ductal carcinoma including: Invasive ductal carcinoma, no special type, in association with solid papillary carcinoma (tumor #1, 1 cm, slices 6 and 7) and invasive ductal carcinoma, no special type (tumor #2, 1.2 cm, slices 9 and 10).

Summary Staging outlines, Tumor #1: Histologic Type: Invasive ductal carcinoma, no special type, in association with solid papillary carcinoma. As well as, Tumor #2: Histologic type: Invasive ductal carcinoma, no special type. Additional findings include ductal carcinoma in situ (DCIS): presently approximately 3.3 cm, spanning slices 10-13.

The behavior of the solid papillary carcinoma component will affect the provisional histology of the first tumor (8523/3) per Rule H17 vs. 8500/3 per Rule H7). Based on the response, we can determine whether this represents a single or multiple primaries (single primary per M13 vs. multiple primaries per M14).

Review all sections of the pathology report carefully for any mention of invasion, or lack of invasion, pertaining to the solid papillary carcinoma.

Per WHO 4th Ed Breast: If there is uncertainty that there is invasion, these lesions should be regarded as in situ. The distinction between in situ and invasive disease in solid papillary carcinoma is difficult.


Behavior--Prostate: What is the correct behavior of intraductal carcinoma from a prostate biopsy with a Gleason score 4+4=8. While highly aggressive, but not suggestive of invasion, coding behavior as /2 seems inappropriate.

WHO classifies intraductal carcinoma of the prostate 8500/2. According to WHO, "the hallmark of intraductal carcinoma of the prostate is a proliferation of prostate carcinoma cells that is within and may significantly expand the native prostatic ducts and acini, with the basal cell layer at least partially preserved." Further, differentiation between intraductal carcinoma and infiltrating high-grade carcinoma of the prostate may require basal cell stains. Under Prognosis, WHO states: " intraductal carcinoma of the prostate on prostate biopsies is often associated with high-grade cancer (with a mean Gleason score of 8) ."

So while it may seem counter-intuitive, assign behavior code /2 when the diagnosis is intraductal carcinoma of the prostate.