MP/H Rules/Histology--Melanoma: Regarding SINQ #20081044, when would you apply Rule H6 rather than Rule H5 for a cutaneous malignant melanoma given that you normally always have a specific cell type mentioned?
For cases diagnosed 2007 or later, Rule H6 is used when you do not have a specific cell type other than regressing melanoma, or malignant melanoma, regressing. If you have regressing melanoma with a specific cell type, apply rule H5.
MP/H Rules/Histology--Ovary: How is histology coded for "serous carcinoma, papillary invasive pattern"?
For cases diagnosed 2007 or later, code the histology 8441/3 [Serous carcinoma, NOS]. Use the Other Sites rules. Start with rule H8 and stop at rule H11. "Pattern" is not one of the terms used to identify a specific type (See H16), so papillary is ignored.
MP/H Rules/Histology--Ovary: How is histology coded for an ovarian tumor diagnosed as an "ovarian clear cell cystadenocarcinoma"? See Discussion.
Final diagnosis for a resected ovary is ovarian clear cell cystadenocarcinoma. In applying the MP/H rules, rule H16 does not apply because cystadenocarcinoma is not included in Table 2. As a result rule H17 applies. Thus it appears the histology should be coded 8440. Cystadenocarcinoma is a specific histologic type and it is assigned the numerically higher histology code. This result differs from pre-2007 SINQ entry 20041045 that states: Code histology to 8310/3 [Clear cell adenocarcinoma, NOS]. This is consistent with the WHO Classification of Tumours and reflects the current practice of placing less emphasis on "cyst-" prefix for ovarian malignancies.
For cases diagnosed 2007 or later:
Assign code 8310 [Clear cell adenocarcinoma] according to rule H13. Ignore "cyst" when determining the histologic type for ovarian malignancies. For this case, the only histology is clear cell.
The histologies for the common ovarian epithelial malignancies are serous, mucinous, endometrioid, clear cell, and transitional cell/Brenner. This clarification will be added to the rules in the next revision.
MP/H Rules/Histology--Pancreas: What is the correct histology code for pancreatic neoplasia III (PanIN III) for cases diagnosed in 2007 and later?
Code histology for PanIN-III to 8148/2 [Glandular intraepithelial neoplasia, grade III]. The Multiple Primary and Histology Coding Rules Manual is the correct source for coding histology.
For cases diagnosed 2007 or later, the following steps are used to determine the histology code:
Open the Multiple Primary and Histology Coding Rules manual. For a pancreas primary, use the Other Sites Histo rules to determine the histology code because pancreas does not have site specific rules.
Go to the SINGLE TUMOR: IN SITU ONLY module, start at rule H1. Code 8148/2 [Glandular intraepithelial neoplasia, grade III]. There is only one histologic type identified.
In the next version of the MP/H rules, the H22 rule "Code 8148/2 (Glandular intraepithelial neoplasia grade III) for in situ glandular in sites such as the (PAIN III)" will be included under H2 as well. Currently the rule is only in the MULTIPLE TUMORS ABSTRACTED AS A SINGLE PRIMARY module and should also be include under the SINGLE TUMOR: IN SITU only module.
MP/H Rules/Histology--Peritoneal primary: Can the cell types from the primary site and a metastatic site be combined to code histology? See Discussion.
Patient has vaginal mass biopsy diagnosed as 'papillary carcinoma with psammoma bodies.' Two weeks later the patient has laparoscopy with multiple peritoneal biopsies, diagnosed as 'well differentiated serous adenocarcinoma'. Patient stated to have peritoneal primary with mets to vagina and was treated with chemotherapy. Do we code the histology to 8441/31 from the primary site biopsies, or can we use 8460/3, combining the cell types from the primary and metastatic sites? Please see SINQ 20041062 for a similar question before the 2007 MP/H rules.
For cases diagnosed 2007 or later, assign code 8441 [serous adenocarcinoma, NOS].
Code the histology from the primary site when available. Do not combine histologies from primary and metastatic sites.
In this primary peritoneal case, the diagnosis from the peritoneal biopsies was serous adenocarcinoma.
MP/H Rules/Histology--Pleura: How is histology coded when the pathology report final diagnosis is "malignant neoplasm, compatible with malignant mesothelioma" if the COMMENT section of the pathology report indicates the tumor has a mixed epithelial and sarcomatoid pattern? See Discussion.
This case was discussed with a pathologist who feels the correct histology should be biphasic mesothelioma (9053/3) because there are both epithelial and sarcomatoid components to this tumor. However, applying the current MP/H Rules, the histology is coded to 9050/3 (mesothelioma, NOS) because the term "pattern" cannot be used to code a more specific histologic type for invasive tumors. If this truly is a biphasic mesothelioma, that data is lost for researchers because the current MP/H Rules fail to capture this information. Should the term pattern be used to code the more specific histology in this case?
Code the histology to malignant mesothelioma, NOS [9050/3]. Apply the MP/H Rules as written until they are revised. The word "pattern" and other terms will be reconsidered for the next iteration of the rules.
MP/H Rules/Histology--Prostate: If a patient is stated to have prostate "cancer" but a pathology report is not available nor is a specific histology stated in the medical record, can this histology be coded to 8140 [adenocarcinoma] instead of 8000/3 [cancer] because the vast majority of prostate cancers are adenocarcinomas?
For cases diagnosed 2007 and later, the correct histology code is 8000/3 [cancer]. The steps used to arrive at this decision are:
Open the Multiple Primary and Histology Coding Rules Manual. Choose one of the three formats (i.e., flowchart, matrix or text). Go to the Other Sites Histology rules because no specific rules have been developed for prostate primaries.
To determine the histology, start at the SINGLE TUMOR: INVASIVE ONLY module, rule H8. The rules are intended to be reviewed in consecutive order within a module. Code the histology documented by the physician when there is no pathology/cytology specimen or the pathology/cytology report is not available. Code the histology as 8000/3 [cancer] because that is the only available information. In the absence of a pathology report or any other histologic confirmation, code the histology based on the information available.