# Coding keratoacanthoma as squamous cell carcinoma or "epidermal thickening"



## CatchTheWind

To those of you who are familiar with the problem surrounding the coding of keratoacanthoma (whereby dermatologists consider it to be a form of squamous cell carcinoma, whereas ICD-10 codes it as "L85.8" (other specified dermal thickening)): 

Is it possible to code a malignant excision with L85.8 as the diagnosis?  Alternately, is there any source that justifies coding the keratoacanthoma as an SCC, in spite of the fact that ICD-10 states otherwise?


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## ddaspooner

Hello!

I have read your question a few times, has this lesion diagnosis been confirmed? You cannot bill a malignant excision code without confirmed pathology. So, if it wasn't biopsied I would use a benign excision code and send it off to pathology. Otherwise, I would biopsy the lesion first with a 11100 and go from there. 

I haven't tried it myself, but if I were to guess, if you used a malignant excision code with "other specified epidermal thickening" I would say its highly likely that you would get a denial. 

Hope that helps!!! Good luck.


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## Fahad.Ogagang@MiraMedGS.com

*Malignancy*



CatchTheWind said:


> To those of you who are familiar with the problem surrounding the coding of keratoacanthoma (whereby dermatologists consider it to be a form of squamous cell carcinoma, whereas ICD-10 codes it as "L85.8" (other specified dermal thickening)):
> 
> Is it possible to code a malignant excision with L85.8 as the diagnosis?  Alternately, is there any source that justifies coding the keratoacanthoma as an SCC, in spite of the fact that ICD-10 states otherwise?



You can only code it as cancer if the documentation states its malignancy

"Keratoacanthoma (KA) is a common low-grade (unlikely to metastasize or invade) skin tumour that is believed to originate from the neck of the hair follicle.

The defining characteristic of KA is that it is dome-shaped, symmetrical, surrounded by a smooth wall of inflamed skin, and capped with keratin scales and debris. It grows rapidly, reaching a large size within days or weeks, and if untreated for months will almost always starve itself of nourishment, necrose (die), slough, and heal with scarring. KA is commonly found on sun-exposed skin, often face, forearms and hands.

Under the microscope, keratoacanthoma very closely resembles squamous cell carcinoma. In order to differentiate between the two, almost the entire structure needs to be removed and examined. While some pathologists classify KA as a distinct entity and not a malignancy, about 6% of clinical and histological keratoacanthomas do progress to invasive and aggressive squamous cell cancers; some pathologists may label KA as "well-differentiated squamous cell carcinoma, keratoacanthoma variant", and prompt definitive surgery may be recommended"


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## mitchellde

more information is needed.  Did the provider excise the lesion, shave it or biopsy it?  The coder cannot decide what procedure to perform, only code what was done.  If this were an excision then you will need to wait for a path report before coding.  If it were a shave removal or a biopsy then you may code without the path but you will code the L85.8 as the diagnosis.  if you have a path report, I would need to know what it states exactly to advise further.


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## CatchTheWind

It was biopsied.  The path report says "keratoacanthoma" and the dermatologist did an excision (for which the surgical path confirmed keratoacanthoma).


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## JesseL

I would think to code based on intent, if the provider thinks it could become a scc and did a wide excision with clear margins I would think to code the malignant excision code.  Course it would've been helpful if the pathologist had wrote "wider excision recommended" or something along those lines..


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## LBernat7

*same issue also with codes D48.5 etc*

we have had this with KA too. Out Drs insist these are SCC and treat them as such. The Path report reads that's its a KA SCC well defined. Our Drs treat this as an SCC they say that's really what's going on there and they code the mal excision and do wide margins etc. Any other info anyone has would be helpful. Same issue is coming up with codes like d48.5 etc, we had one that was D48.5 on path wording stating that it was a clark's nevus junctional with unusual features associated with Melanoma in Situ cannot be excluded. Dr treated excision as malignant excision would be done clearing all margins and going deep.


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