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).
Histology (Pre-2007)--Breast: What code is used to represent the histology "Ductal carcinoma in situ; 6 mm focus of invasion is a pure mucinous carcinoma that appears to have arisen in the background of encysted papillary carcinoma."
Code to mucinous (8480) since that is the only clearly invasive component of this diagnosis.
According to our pathologist consultant, "Encysted papillary carcinoma is the same thing as intracystic papillry carcinoma, which I think of as an intraductal papillary carcinoma which has greatly expanded the duct to form a cyst-like structure. It generally behaves in an in-situ rather than an invasive fashion. The only clearly invasive component is the mucinous carcinoma, which is what I would code."
Reportability/Histology-Gallbladder: Is high grade biliary intraepithelial neoplasia of the gallbladder reportable?
High grade biliary intraepithelial neoplasia of the gallbladder is reportable. Assign code 8148/2. It is also known as biliary intraepithelial neoplasia grade 3, or BilIN-3.
Immunotherapy: Is immunotherapy ever palliative treatment according to any oncologists or SEER?
Any treatment that destroys or modifies cancer tissue should be recorded as the appropriate type of treatment -- chemo, immuno, etc. Even if immunotherapy is given for symptoms/palliative treatment, it is likely to kill off tumor cells.
EOD-Extension--Ovary: What code is used to represent this field for an ovarian primary presenting with "spread to the omentum"?
For cases diagnosed 1998-2003:
Code the EOD-Extension field to 75 [Peritoneal implants, NOS] because the size of the implants on the omentum is not known.
Note 6 was added to the EOD scheme which states that both direct extension and discontinuous metastasis to the omentum are coded in the range 70-75 depending on how the peritoneal implants are described.
Reportability--Carcinoid: Is a diagnosis of carcinoid heart disease, based solely on clinical information and no pathology, reportable?
Carcinoid heart disease is not reportable but this diagnosis indicates that the patient likely has a carcinoid tumor which may be reportable. Obtain further information.
Reportability--Brain and CNS: Is a thalamic amyloidoma reportable if so what histology code is used?
Thalamic amyloidoma is not reportable. Amyloidoma (tumoral amyloidosis, amyloid tumor) is a tumor-like deposit of amyloid. It is not neoplastic. Amyloid is a protein derived substance deposited in various clinical settings.
Histology--Ovary: What is the correct ICD-O-3 histology code for sertoliform endometrioid carcinoma of the ovary?
Assign 8380/3. Sertoliform endometrioid carcinoma is a variant of endometrioid carcinoma according to the WHO Classification of Tumors of Female Reproductive Organs, 4th edition. There is no specific ICD-O-3 code for this variant.
Reportability--Heme & Lymphoid Neoplasms: If not specified as primary, idiopathic, or essential, is thrombocytosis, NOS reportable?
Updated May 2026
Thrombocytosis, NOS is not reportable for any year of diagnosis.
Unless the disease is specified as primary, idiopathic, essential, or the physician states there is a myeloproliferative neoplasm, the term thrombocytosis, NOS is not reportable. Thrombocytosis, NOS, is the presence of high platelet counts in the blood. Thrombocytosis can be associated with chronic infections and other diseases as well as with myeloproliferative disease.