What diagnosis code should you use when sending a skin biopsy to pathology?
a) D48.5 Neoplasm of uncertain behavior of skin, or
b) D49.2 Neoplasm of unspecified behavior of bone, soft tissue, and skin
The answer is b! Use an unspecified code when a specific diagnosis code is not known at the time of encounter. This is a common mistake I see in dermatology, general surgery and primary care.
Uncertain has a specific meaning in ICD-10. It means that the specimen has been examined by the pathologist and it can’t be determined if the neoplasm is benign or malignant. An uncertain neoplasm is reported after the pathologist’s report, not when sending the specimen for biopsy.
According to ICD-10, there are specific categories of codes that are used for neoplasms of uncertain behavior. They are:
These classify the neoplasm by site and should be used when “i.e., histologic confirmation whether the neoplasm is malignant or benign cannot be made.”
Unspecified, on the other hand, means that a definitive diagnosis cannot be made at the time of the encounter.
The general guidelines say,
“If a definitive diagnosis has not been established by the end of the encounter, it is appropriate to report codes for sign(s) and/or symptom(s) in lieu of a definitive diagnosis.”
This is exactly the situation when a biopsy is taken and sent for pathology.
This is confirmed in the general guidelines related to neoplasm.
“Chapter 2 of the ICD-10-CM contains the codes for most benign and all malignant neoplasms. Certain benign neoplasms, such as prostatic adenomas, may be found in the specific body system chapters. 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.”
The word uncertain is related to a histologic determination. It doesn’t describe “we aren’t sure so we are sending it to pathology.”
Here are links to more about diagnosis coding and specialty specific services
- Coding for biopsy | Should we wait for pathology?
- Diagnosis Coding | Not just for claims anymore
- Roadmap to dermatology coding