#2: Kidney, renal pelvis
Source 1: WHO Class Urinary Tumors
Reportability--Kidney: Is a renal cell neoplasm stated to be multilocular clear cell renal cell neoplasm of low malignant potential a reportable tumor if the physician refers to the tumor as renal cell carcinoma in a follow-up note after surgery? If reportable, how is histology coded? See Discussion.
The partial nephrectomy final diagnosis is renal cell neoplasm. The College of American Pathologists (CAP) Summary lists histology as: multilocular clear cell neoplasm of low malignant potential. The diagnosis comment adds: This neoplasm currently termed multilocular clear cell renal cell neoplasm of low malignant potential (WHO 2016), was previously termed cystic renal cell carcinoma.
For now, report the case and code to 8310/3.
In the 3rd Ed WHO Tumors of the Urinary System, multilocular clear cell RCC is coded as 8310/3, however the recent 4th Ed WHO Tumors of Urinary System notes this term is obsolete and a synonym for multilocular cystic renal neoplasm of low malignant potential (8316/1) which would be non-reportable. Per WHO 3rd Ed these tumors never recur or metastasize which may be why the behavior code is shown as /1. The standard setters must review this terminology change in relation to reporting the case as it may impact incidence rates.