Wiki Neoplasm of uncertain behavior versus neoplasm of unspecified behavior

[roxydeco1]

I was taught that D48.5 Neoplasm of uncertain behavior of skin should only be used when the pathologist cannot determine if a neoplasm is benign or malignant. It is a specific code to be utilized after a histologic determination has been made, not a code to be used at the time the sample is obtained.

I was also taught that D49.2 Neoplasm of unspecified behavior of bone, soft tissue and skin is the appropriate code to use related to the biopsy (obtaining the sample).

However, it seems like the derm world (around me at least) uses D48.5 Neoplasm of uncertain behavior of skin with the biopsy (obtaining the sample).

Can anyone help? Is anyone aware of how the AAD views this?

 

[thomas7331]

Any ICD-10 code from chapter 2 (neoplasms C00-D49) really should be supported up with a pathology report. A provider cannot make the determination that any tissue sample is neoplastic - whether malignant, benign or of uncertain behavior - without a microscopic review. That would apply to both codes D48.5 and D49.2, which only differ in that they describe a different anatomical type of tissue.

Unfortunately, it has become a common misunderstanding in dermatology to confuse 'uncertain behavior' with 'uncertain diagnosis' or 'unknown malignancy', and these are not the same thing. This incorrect use of the 'uncertain behavior' codes has been going on for so long, that it has simply become common practice and is widely accepted. So your practice will just have to decide if they want to follow the common practice or stick more strictly to the proper use of ICD-10.

The correct way to code a suspicious skin lesion that does not yet have a confirmed diagnosis, for an outpatient encounter, is to either code is based on the description of the lesion as documented (e.g. 'skin lesion' is classified to L98.9), or otherwise wait for the pathology report and code it based on those findings. But technically speaking, if the provider is confident in their judgments that the lesion is a neoplasm of uncertain behavior without a pathology report, and they have diagnosed is as such in their written documentation, then as a coder we should accept that and assign the appropriate code.

 

[Youngmedconsult]

Thomas7331, I agree with most of what you say but want to correct one thing. Uncertain behavior is a diagnosis made by a pathologist. It is rarely made but it would be found on the pathology report. If a provider is does not have a histologic diagnosis for the the lump or mass then that is what it is coded as. A lump or mass, until such time as a pathology report comes back.

See the attached insurance coding education article

Looking at the ICD-10-CM Guidelines it states: "To properly code a neoplasm, it is necessary to determine from the record if the neoplasm is benign, in-situ, malignant, or of uncertain histologic behavior". Histologic as in the analysis of the structure of cells with a microscope. I think this is one of the largest misunderstandings in coding. Great job with the rest of the details Thomas!