#1: Solid Tumor Rules (2018)
Source 1: 2018 Solid Tumor Rules
Solid Tumor Rules (2018)/Histology--Lung: The Histology coding guidelines for lung cancer state to code histology when stated as type or subtype but not to code when described as pattern. How should the histology be coded (Adeno, NOS or Adeno, Mixed subtypes) if the College of Americal Pathologists Protocol of the pathology report lists the following: Histologic type: Adenocarcinoma, papillary (90%), lepidic (8%), and solid (2%) patterns?
The term/modifier "patterns" is no longer allowed to code a specific histology according to the Lung Solid Tumor H rules. Disregard the papillary, lepidic, and solid patterns and code histology to adenocarcinoma, NOS (8140/3).