Scenario: 2024

Question: How would you code Histology?

Answer: 8570 Endometrioid carcinoma with squamous differentiation

Rationale & Discussion:

The term “most specific” usually refers to a subtype/variant.

The term “distinctly different” refers to different rows.

Endometrioid adenocarcinoma and Endometrioid carcinoma with squamous differentiation are on the same row so they aren’t considered distinctly different per Note 3 in STR. Therefore, we will code the histology from the biopsy as Endometrioid carcinoma with squamous differentiation which is the most specific term according to Note 1 in STR.

Other Sites Solid Tumor Rules For Cases Dx’d 2023+ 2024 Update

Page 1 Changes from 2007 MPH Rules

  1. The previous 2007 MPH Rules instructed you to “Code the histology from the most representative specimen.” For all sites included in 2023 Other Sites Solid Tumor Rules, the instruction is now “Code the most specific histology from biopsy or resection. When there is a discrepancy between the biopsy and resection (two distinctly different histologies), code the histology from the most representative specimen (the greater amount of tumor).”

Page 86. Code the most specific pathology/tissue from either the resection or biopsy.

Note 1: The term “most specific” usually refers to a subtype/variant

Note 3: When there is a discrepancy between the biopsy and resection (two distinctly different histologies/different rows), code the histology from the most representative specimen (the greater amount of tumor).