SEER Inquiry System - View
Source 1: WHO Class Endocrine Tumors
Source 2: 2007 MP/H Rules
MP/H Rules/Histology--Thyroid: How is the histology coded for a poorly differentiated thyroid carcinoma with rhabdoid phenotype arising in a papillary carcinoma?
For cases diagnosed 2007 or later, code the histology as papillary carcinoma, poorly differentiated [8260/33].
NOTE: The WHO classification lists grade III papillary carcinoma as one of the synonyms for poorly differentiated thyroid carcinoma.
The steps used to arrive at this decision are:
Step 1: 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 Histo rules because site specific rules have not been developed for this primary.
Step 2: Start with the SINGLE TUMOR: INVASIVE ONLY module, rule H8. The rules are intended to be reviewed in consecutive order within a module. Per rule H13 “phenotype” is not a term used to code a more specific histology. Moving to Rule H14 the histology is coded 8260/3 [papillary adenocarcinoma]. Stop at Rule H14.