Although your Merkel cell cancer and unspecified nature neoplasm coding familiarity is under attack from the added ICD-9 codes specificity, you can still protect your practice from incorrect entries by following these simple rules.
ICD-9 2010 brings you specific options for Merkel cell carcinoma which will allow for more accurate coding and prevents you from lumping these in with your standard neoplasm diagnosis codes. This does not seem like a big deal but is needed information to know if you are ever audited or want to make sure you are paid correctly.
Merkel Cell Cancer Coding
The specific codes for Merkel cell are 209.31 Merkel Cell Carcinoma of the face, 209.32 Merkel Cell carcinoma of the scalp and neck, and 209.36 Merkel Cell Carcinoma of other sites. Using ICD-9, you have to lump the Merkel cell cancer under the 173.xx (other malignant neoplasm of skin) which are most commonly used for your typical basal and squamous cell carcinomas.
When it has Metastasized
If you are treating Merkel cell cancer that has already metastasized, then you have to use a different subset of ICD-9 codes under the 2010 guidelines. The 209.3x codes are for Malignant poorly differentiated neuroendocrine tumors, Code 209.30 are for Malignant poorly differentiated neuroendocrine carcinoma, any site, is not appropriate for secondary Merkel Cell Carcinoma. You will instead need to use the 209.75 Secondary Merkel Cell Carcinoma.
The 209.75 is actually used for several instances which include:
- Nodal presentation
- secondary Merkel Cell, any site
- unknown primary site