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Left frontal mass biopsy diagnosis comment states: Given the synaptophysin and patchy CD34 staining of these cells, the possibility of ganglioglioma and pleomorphic xanthoastrocytoma is raised. Astroblastoma and ependymoma were considered given the perivascular pseudorosettes, however GFAP staining is quite limited against these tumors. Reticulin stain shows limited perivascular reticulin staining however. Nevertheless, the necrosis, mitotic activity and elevated mitotic activity would point to a malignant neoplasm. Given the neural and limited GFAP staining, a generic classification of neuroglial is provided.

This is the only available information. Further clarification or discussion with the physician or pathologist is not possible. Therefore, is this diagnosis of neuroglial tumor equivalent to that described in SINQ 20091037?

SINQ 20160008 discusses the reportabilty and diagnosis date for liver primaries where imaging references the LI-RADS category as LR-5 or LR-5V. The 2018 SEER Coding and Staging Manual, Appendix E Reportable Example #16, demonstrates this concept. According to the LI-RADS categories a value of 5 is "definitely HCC" and is concordant with OPTN 5. Often we see only the OPTN categorization.

There are two histologies provided in the final diagnosis, malignant spindle cell neoplasm (8004/3) and atypical fibroxanthoma (8830/3). There is a definitive diagnosis of the non-specific histology, but the more specific histology is only described using ambiguous terminology.

The external ear (C442) is included in the Head and Neck schema for diagnosis year 2018 and later. The Head and Neck Histology Rules indicate ambiguous terminology cannot be used to code a more specific histology. So ignoring the atypical fibroxanthoma, because it is modified by ambiguous terminology, we are left with a non-reportable site and histology combination (C442, 8004/3).

Diagnoses of malignant atypical fibroxanthomas are regularly diagnosed using the syntax above in our area. Follow-up with the physician or pathologist is generally not possible as these cases are received from dermatopathology clinics only. The pathology report is the only information that will be received. If the reportable diagnosis of malignant atypical fibroxanthoma is ignored per the current Solid Tumor Rules, incidence cases will be lost.

According to the Multiple Primaries/Histology Rules in place at the time of the 2016 diagnosis, verrucous carcinoma was listed as a specific type of squamous carcinoma (Chart 1). However, in the current Solid Tumor Rules, verrucous carcinoma is not listed in Table 4 (Tumors of Oral Cavity and Mobile Tongue) either as a specific histology or as a specific subtype/variant of squamous carcinoma. The only subtype/variant listed for these sites is acantholytic squamous cell carcinoma (8075).

Verrucous carcinoma is not listed in Table 4, making it unclear if it should be a different histology for these specified sites. However, verrucous carcinoma is listed as a specific subtype/variant of squamous carcinoma for other sites (e.g., Table 3).

Example: Left thyroid lobectomy with final diagnosis

When the only mention of encapsulation is included in the tumor characteristics of the College of American Pathologists (CAP) summary, not the pathologist's choice of histologic type, what is the preferred histology?

Example: Patient has a secretory carcinoma of minor salivary gland tissue (mammary analogue secretory carcinoma [MASC]) of the mucosal lower lip; it is unclear which table to use and how to arrive at the correct histology using the H Rules.

Rule H1 (code the histology when only one histology is present) states, Note 1: Use Tables 1-9 to code histology. There is no table that includes the lip. The correct histology should be 8502 which is listed in Table 6 (Tumors of Salivary Glands) however this does not correspond to minor salivary glands of the mucosal lip (site C003 per ICD-O-3 coding instruction).

The 2018 ICD-O-3 Update table does not include this histology, however Table 6 indicates code 8502 (secretory carcinoma) is a new code that was approved by IARC/WHO.

The ICD-O-3 only includes this histology as secretory carcinoma of breast. Therefore, in order to arrive at the correct histology, one must be aware of previous SINQ entries 20160036 and 20130003 that indicate secretory carcinoma (or MASC) is histology 8502. However, these are related to MP/H Rules, so registrars may be hesitant to apply this guideline to cases coded using Solid Tumor Rules.

Rule PH28 confirms the more specific histologies are ignored if this is truly a low grade B-cell lymphoma (i.e., non-Hodgkin lymphoma, NOS) since both MALT lymphoma and LPL are more specific types of low grade B-cell lymphomas. This leaves only a diagnosis of low grade B-cell lymphoma with plasmacytic differentiation to consider.

SINQ 20130033 states a low grade B-cell lymphoma with plasmacytic differentiation should be coded as 9680/3 (diffuse large B-cell lymphoma (DLBCL)). However, DLBCL is a high grade B-cell lymphoma, not a low grade B-cell lymphoma.

If the pathologist classifies this as a non-specific low grade B-cell lymphoma, and clarifies that this may represent a more specific type of low grade B-cell lymphoma (MALT lymphoma or LPL), should the histology be coded to a high-grade lymphoma (DLBCL) or non-Hodgkin lymphoma, NOS?