MP/H Rules--Corpus uteri: How is histology coded for an endometrial tumor described as an "endometrioid adenocarcinoma with prominent squamous metaplasia"?
For cases diagnosed 2007 or later:
Endometrioid adenocarcinoma with squamous metaplasia is coded 8570 [Adenocarcinoma with squamous metaplasia]. This falls under the Histology Coding Rules for Other Sites, rule H17. The code for Endometroid adenocarcinoma is 8380. The code for Adenocarcinoma with squamous metaplasia is 8570. The histology with the numerically higher ICD-O-3 code is Adenocarcinoma with squamous metaplasia -- 8570.
EOD-Extension--Mycosis Fungoides: Explain the difference between extension codes 25 [% of body surface not stated, no tumors] and 30 [skin involvement, NOS; extent not stated, no tumors. Localized, NOS]?
For cases diagnosed 1998-2003:
For mycosis fungoides: Use code 25 when skin involvement is present but only a general location/site is mentioned (i.e., face, legs, torso, arms).
Use code 30 when there is skin involvement but there is no mention of location/site.
Multiplicity Counter: Are in situ tumors diagnosed more than 60 days after invasive tumors of the same site and histology included in the Multiplicity Counter?
If an in situ tumor following an invasive tumor is a single primary according to the multiple primary rules for that particular site, include the in situ and the invasive tumors in the multiplicity counter.
MP/H Rules/Multiple Primaries/Histology--Prostate: How many primaries should be abstracted and how should the histology field(s) be coded for a case in which the pathology specimen showed adenocarcinoma in 20% of the tissue and sarcoma in 50% of the tissue? See Discussion.
Patient has TURP. The final path diagnosis is adenocarcinoma in 20% of tissue and sarcoma in 50% of tissue.
Because it is unknown whether there is a single or multiple tumors, rule M1 (Other Sites) is used which states the case is to be abstracted as a single primary.
Single invasive histology rules are followed to rule H16, but table 2 does not contain a mixed code for this situation, even though ICD-O-3 has a code 8933/3 for "adenosarcoma". Therefore, rule H17 is applied that states to use the highest code, which in this case would be 8800/3 [Sarcoma, NOS]. Is this correct?
For cases diagnosed 2007-2014, code as two primaries, one adenocarcinoma and the other sarcoma.
This is two tumors (adenocarcinoma and separate sarcoma) until proven otherwise. Do not code as adenosarcoma, as this is a gyn-specific diagnosis. Adenosarcoma of the prostate is not a recognized entity in the WHO classification of prostate tumors.
Multiple primaries/Histology--Heme & Lymphoid Neoplasms: How many primaries should be reported for a bone marrow biopsy diagnosis of "lymphoproliferative disorder, small cell lymphocytic lymphoma/small cell lymphocytic leukemia consistent with marginal zone lymphoma"?
According to our hematopoietic/lymphoid neoplasm physician expert, abstract one primary with the histology code 9699/3 [marginal zone lymphoma]. The pathologist is using the expression "small lymphocytic lymphoma" in a descriptive manner (marginal zone lymphoma is comprised of small lymphocytes) rather than in a "diagnostic" manner.
Grade, Differentiation/Priorities: Which has priority, the differentiation or the nuclear grade for a liver biopsy histology described as "well differentiated hepatocellular carcinoma, nuclear grade 3/4"?
For most sites, differentiation has priority over the nuclear grade when both are specified (excluding breast and kidney). Assign grade code 1 [well differentiated] to the example above.
Multiplicity Counter-Breast: The general instructions say to ignore separate microscopic foci when determining when to use the single tumor or multiple tumor modules. Do these instructions apply if sizes are given for the foci? See Discussion.
For instance, would a 1.2 cm breast tumor with 3 scattered microscopic foci ranging from 2-4 mm be treated as multiple tumors (4), or as a single tumor?
If the microscopic foci are measured and listed as part of the diagnosis, they should be counted as multiple tumors.
MP/H Rules/Multiple primaries - - Melanoma: How many primaries are reported when a patient presents with a malignant melanoma (NOS) and a separate lentigo maligna, both on right chest? See Discussion.
MP/H rule M5 states that melanomas with ICD-O-3 histology codes that are different at the third number are multiple primaries. However, the 2007 MP/H fundamentals Webcast session on melanoma rules states that this is not two histologic types. Lentigo maligna is a growth pattern, not a histologic type. Will clarification be included in the next MP/H rules revision?
For cases diagnosed 2007 or later, two primaries are to be reported for this case. Rule M5 applies because there is a difference in the histology codes at the third digit.
Clarifications regarding histologic types of melanoma will be added to the rules when they are revised.
EOD-Lymph Nodes--Head & Neck: When a physician provides only "Stage IV" (i.e., an abbreviated stage) for a right posterior tongue primary with lateral extension into the oropharynx and hypopharynx, can you assume "palpable" level 2, 3 and 5 lymph nodes are involved?
For cases diagnosed 1998-2003:
Code the EOD-Lymph Nodes field to 9 [Unknown], based on the information provided.
The physician's statement of an N category from a TNM may be used to determine lymph node involvement in the absence of other information. However, you cannot assume nodal involvement based on the incomplete staging information of "Stage IV" for a base of tongue primary. For this primary site, extension into the hypopharynx from this primary is equivalent to T4/Stage IV. Therefore you cannot assume the clinician's assessment of the case as Stage IV represents his assessment of lymph node involvement.