Pathology/Lab Coding Alert

Pathology coders may see codes from the "Morphology of Neoplasms" table (in the ICD-9 appendix) used to describe specimens. These codes are used for tumor registry, and although you can't report them on claims as diagnosis codes, you can "translate" them to ICD9 Codes if you know how. Remember, familiarity with these codes is for educational purposes only never report these codes on a claim form.

The morphology codes begin with the letter M followed by five digits. The first four digits identify the neoplasm histologic type, e.g., adenoma or lipoma. A slash and fifth digit follow, indicating the behavior of each neoplasm, corresponding to the ICD-9 neoplasm table:

 

/0 benign (ICD-9 sections 210-229)

/1 unspecified for categories M8000-M8004 (ICD-9 section 239)

/1 uncertain for categories M8010+ (ICD-9 sections 235-238)

/2 carcinoma in situ (ICD-9 sections 230-234) (also called intraepithelial, noninfiltrating, or noninvasive)

/3 primary malignant (ICD-9 sections 140-195, 200-208)

/6 secondary malignant (ICD-9 sections 196-198)

For example, an adenomatous polyp not otherwise specified is M8210/0. This code indicates that the growth is benign, which translates to 211.3 for colon. A villous adenoma of the colon is M8261/1, meaning uncertain behavior, which is reported as 253.2. Tubular adenocar-cinoma is M8211/3, meaning it is a primary malignancy, reported as 153.0-153.9 depending on the exact location in the colon.