Solid Tumor Rules/Multiple primaries--Breast: How many primaries should be abstracted when papillary carcinoma is identified in two biopsies and a subsequent lumpectomy identified invasive ductal carcinoma with multifocal ductal carcinoma in situ (DCIS)? See Discussion.
Solid Tumor Rules (2018)/Histology--Breast: How is histology coded and which rule applies for a single in situ tumor that is described as an encapsulated papillary carcinoma (EPC) with conventional ductal carcinoma in situ (DCIS)? See Discussion.
Solid Tumor Rules (2018)/Histology--Head & Neck: How is histology coded for a p16-positive squamous cell carcinoma of the base of tongue? Is p16-positive squamous cell carcinoma equivalent to a diagnosis of squamous cell carcinoma human papilloma virus (HPV)-positive (8085)? See Discussion.
Solid Tumor Rules (2018)/Histology--Head & Neck: Where does cytology rank on the Priority Order for Using Documentation to Identify Histology for Head and Neck primaries? See Discussion.
Solid Tumor Rules (2018)/Multiple primaries--Brain and CNS: Rule M6 notes a diagnosis of glioblastoma multiforme is a new primary when it follows a diagnosis of a glial or astrocytic tumor. Does this rule apply if the subsequent diagnosis was just, glioblastoma, NOS or one of the subtypes/variants of glioblastoma multiforme? See Discussion.
Solid Tumor Rules (2018)/Histology--Cervix uteri: What is the correct histology code for malignant mixed Mullerian tumor (MMMT/Carcinosarcoma)? See Discussion.
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?
Solid Tumor Rules (2018)/Behavior--Brain and CNS: The Behavior coding instructions in the Non-Malignant Central Nervous System (CNS) Equivalent Terms and Definitions section refer to Table 1 for help coding behavior when the other priority order instructions do not apply; however, the behavior cannot be reasonably determined using Table 1 alone for all WHO Grade I neoplasms. Should an additional default, such as the ICD-O-3 or Tables 5 and 6, be used to determine behavior? See Discussion.
Solid Tumor Rules (2018)/Laterality--Brain and CNS: How is laterality coded for bilateral non-malignant central nervous system (CNS) or malignant CNS tumors now that laterality is no longer used to identify these tumors as multiple primaries? See Discussion.