An official website of the United States government
Home
SEER Inquiry System - Report
Produced: 05/05/2026 4:04 PM
Question 20130192
Inquiry Details
References:
2007 MP/H Rules
Question:
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.
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?
Answer:
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.
Cancer Site Category:
N/A
Data Item Category:
Histology
Other Category:
N/A
Year:
2013
