Rewritten Instructions

Important

These modules are archived and should only be referenced for historical purposes.

The coding instructions in the front of the book are being rewritten, clarified, and made more user-friendly.

Example

Morphology terms have five-digit code numbers ranging from 8000/0 to 9989/1. The first four digits indicate the specific histologic terms (Table 8).

The fifth digit, after the slash or solidus (/), is a behavior code, which indicates whether a tumor is malignant, benign, in situ or uncertain whether malignant or benign.

A separate one-digit code for histologic grading or differentiation is provided

Example of Revised Wording

Old Wording

If a diagnosis indicates two different degrees of grade or differentiation (e.g., "well and poorly differentiated" or "grades II-III"), code to the higher grade.

New Wording

Grading or differentiation code: Assign the highest grade or differentiation code described in the diagnostic statement.