Tip: Coding for cancer

Within the Alphabetic Index of ICD-9-CM is a Neoplasm table that assists coders in assigning diagnosis codes (Vols. 1-2). The table is structured based off the specific location of the neoplasm as well as the type of neoplasm. There are four types of neoplasms on the neoplasm table:

Malignant neoplasms can be classified as either primary, secondary, or carcinoma in situ. A primary malignant neoplasm is the originating site of the neoplasm and will remain the primary site even if the neoplasm spreads or invades other body areas. A secondary site or “metastasis” is where the primary neoplasm has spread to another site. Carcinoma in situ is generally a non-invasive malignant neoplasm. 

 

If the provider documents a histiological term to describe a neoplasm, it is always recommended to reference that term first to determine which column on the table should be used. For example, if a provider documents “oat cell carcinoma” you will see that the ICD-9 coding manual has an instructional note to See Neoplasm, by site, malignant and for unspecified sites it will default to a malignancy neoplasm of the lung (162.9).

 

Sequencing for neoplasms is generally assigned based on the reason for the encounter and/or the specific neoplasm being evaluated or treated. The site listed as the first-listed or principal diagnosis is the neoplasm being evaluated or treated during the current encounter/admission. Please note that this may be a secondary site. An exception to this rule would be if the sole purpose of the encounter was to receive treatment (e.g. radiation therapy or chemotherapy) then the first-listed or principal diagnosis would be either V58.0 or V58.1x respectively. Coders may assign additional codes for the neoplasm(s) that were being treated. 

 

In instances where the patient is being seen for a metastatic site and the documentation states that the patient has an “unknown primary site,” assign code 199.1 (Malignancy, unspecified site).

 

Note: Shannon McCall, RHIA, CCS, CPC, CPC-I, CCDS, director of HIM/Coding at HCPro, Inc., in Marblehead, MA, and an ACDIS advisory board member provided this tip.