Question: When I am performing a shave biopsy, I append diagnosis code D48.5 to the service.  My coder is telling me that it is incorrect, and I should use D49.2 instead.  Who is correct?

 Answer: The coder is correct on this one.  D48.5 is Neoplasm of Uncertain Behavior of Skin and D49.2 is Neoplasm of Unspecified Behavior of Bone, Soft Tissue, and Skin.  In the ICD-10-CM Guidelines (C.2) 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.”  This indicates that the tissue has been studied microscopically.  D48.5 is to be assigned when a lesion has been sent to pathology and has come back with a reading of uncertain behavior (dysplastic, atypical, etc) by the pathologist.  D49.2 is assigned when the physician/other provider does not know whether the lesion is benign or malignant, or the documentation is not specific. Remember, uncertain behavior is not the same as uncertain diagnosis.

*This is based on information available as of 04/07/22.