SEER Inquiry System - Search

Apply 2007 MP/H rule H6 and assign the numerically higher ICD-O-3 code that reflects PNET (9364/3).

According to the WHO Tumors of Soft Tissue and Bone, though Ewing sarcoma ICD-O-3 code is 9260/3, Ewing sarcoma with a higher degree of neuroectodermal differentiation present is classically termed peripheral neuroectodermal tumors (PNET).  WHO does not offer guidance how to classify tumors stated to be Ewing sarcoma PNET.

Histology code 9364/3 is assigned for a Ewing/PNET that arises outside of the brain/CNS. Peripheral neuroectodermal tumor (PNET) and peripheral primitive neuroectodermal tumor (PPNET) are Ewing family tumors.

Histology code 9473/3 (PNET, primitive neuroectodermal tumor, central primitive neuroectodermal tumor, or supratentorial PNET) is only used for tumors arising inside the brain/CNS.

Instruction #5 in the Priority Order for Using Documentation to Identify Histology of the Head and Neck Solid Tumor Rules, Item 5.B., refers to cytology in the documentation though cytology is not listed before this. In H&N tumors, cytology is usually performed on lymph nodes and seldom on a primary tumor. Cytology will be added to H&N in the next update.

HPV-positive is not equivalent to HPV-mediated (p16+). According to the 2018 SEER Manual, HPV-type 16 refers to virus type and is different from p16 overexpression (p16+). HPV status is determined by tests designed to detect viral DNA or RNA. Tests based on ISH, PCR, RT-PCR technologies detect the viral DNA or RNA; whereas, the test for p16 expression, a surrogate marker for HPV, is IHC. HPV testing must be positive by viral detection tests in order to code histology as 8085.

Code the histology to mixed germ cell tumor [9085/3] per Rule H16; code the appropriate combination/mixed code when there are multiple specific histologies.

According to the WHO Classification of Tumors of the Male Genital Organs, tumors of more than one histologic type (mixed forms) can occur in any combination of various germ cell histologies including embryonal, yolk sac, teratoma, and choriocarcinoma. Mixed teratoma and seminoma is included under histology code 9085/3 [mixed germ cell tumor] in the ICD-O-3. The revised MP/H rules will expand on these mixed testicular histologies.

Priority for coding histology is using the diagnosis from the primary site (when possible) over the histology from a metastatic site. The presence of teratoma, NOS in the retroperitoneal lymph nodes does not change the histology code.

Code histology to 8500/2. Per April 2019 update: Rule H5 applies: Code DCIS 8500/2 when there is a combination of DCIS and any other carcinoma in situ.

The 4th Ed WHO Tumors of the Breast states that tumors with encapsulated papillary carcinoma in situ in the absence of DCIS in the surrounding tissue have a very favorable prognosis. Only tumors without DCIS should be coded to 8504/2. The component of DCIS will determine treatment.

For cases diagnosed 2007 or later:

When the final diagnosis indicates that the microscopic section contains the detailed diagnosis, use the microscopic description to code the histology.

Otherwise, code from the final diagnosis only and not from the microscopic description. The final diagnosis is usually the pathologist's conclusion after consideration of the various choices listed in the microscopic description. The histology code should represent the pathologist's final conclusion.

For tumors diagnosed prior to 2007:

Code as two primaries, assuming the tumors are separate and the margins are clear/negative. Code 8071/3 [Invasive squamous cell ca, keratinizing] and 8500/3 [Ductal carcinoma, "microinvasive"].

For tumors diagnosed 2007 or later, refer to the MP/H rules. If there are still questions about how this type of tumor should be coded, submit a new question to SINQ and include the difficulties you are encountering in applying the MP/H rules.

Assign 8122/3 for urothelial carcinoma, extensive sarcomatoid dedifferentiation. Sarcomatoid dedifferentiation refers to the histologic type. 8122/3 is also correct for the following diagnoses.

         Urothelial carcinoma, sarcomatoid carcinoma or sarcomatoid variant  8122/3

         Urothelial carcinoma with sarcomatoid features  8122/3

Code NSCLC to 8046/3.

Do not change a histology code simply to assign TNM to the case. AJCC does not determine histology coding. While pathologists are no longer encouraged to use NSCLC, it does not mean the term and code are obsolete. NSCLC could be any number of histologies such as adenocarcinoma or squamous carcinoma. A diagnosis of NSCLC indicates that the initial exam of the tissue did not identify a more specific type of NSCLC. Additional immunohistochemical testing is needed to determine the histology. Update the case if better information becomes available from subsequent tests/review.

When analyzing the data, researchers and physicians will be able to identify the cases where the pathologist was unable to or did not perform further testing to determine a specific histology which drives treatment and survival.

Code histology to adenocarcinoma, NOS (8140/3). The World Health Organization and the College of American Pathologists no longer recognize non-mucinous carcinoma/adenocarcinoma, NOS. Pathologists are discouraged from using this term. Microinvasive/minimally invasive lung tumors have very specific criteria and these criteria do not apply to non-mucinous carcinoma, NOS.