Pathology/Lab Coding Alert

Question: Our pathologist examined a skin lesion of the patient’s right ear submitted by a dermatology client with a working diagnosis of actinic keratosis. The pathology report documented proliferation of atypical squamous cells that extend into the underlying dermis and p53-stain positive findings. How should I code the diagnosis?

Texas Subscriber

Answer: The pathologist should provide a narrative description of the final diagnosis. From the description of the pathology report, this looks more likely to be a squamous-cell carcinoma. But you need to certify that finding with the pathologist before assigning a code.

The code for actinic keratosis is L57.0 (Actinic keratosis). The code for squamous cell carcinoma of the ear is C44.222 (Squamous cell carcinoma of skin of right ear and external auricular canal).

You should not assign the ordering diagnosis after a pathology report that provides a different, final diagnosis. If the documentation is unclear, you should ask the physician for a clarification.