Oncology & Hematology Coding Alert

Reader Question:

No Definitive Code for Pilomatrixoma

Question: What ICD-9-CM code can we submit for malignant pilomatrixoma of the scalp?

New York Subscriber

Answer: There isn’t a very specific code for pilomatrixoma, which is a relatively uncommon tumor. For malignant pilomatrixoma of the scalp, ICD-9-CM code 173.49 (Other specified malignant neoplasm of scalp and skin of neck) would be assigned. 

ICD-10-CM: You have a head-on direct match for code 173.49 in ICD-10-CM. This code maps to code C44.49 (Other specified malignant neoplasm of skin of scalp and neck) in ICD-10-CM.

What is pilomatrixoma? A pilomatroxoma is a benign tumor of the hair appendage that presents as a solitary nodule. Malignancy in a pilomatroxoma is very rare. Multiple pilomatrixomas are known to occur in conditions like myotonic dystrophy, a form of muscular dystrophy.