C44.301 (Unspecified malignant neoplasm of skin of nose) compared with D48.5 (Neoplasm of uncertain behavior of skin), from the official CMS tabular data. C44.301 and D48.5 name the same anatomical site (ala nasi) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (ala nasi)
The behavior documented for the site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column of the neoplasm table, and therefore which code, applies.
Source: CMS Table of Neoplasms
Same site, different neoplasm behavior. C44.301 and D48.5 name the same anatomical site (ala nasi) with a different neoplasm behavior.
From the CMS/CDC Table of Neoplasms: the behavior documented for that site — malignant primary, secondary, carcinoma in situ, benign, uncertain or unspecified — decides which column, and therefore which code, applies.
| C44.301Unspecified malignant neoplasm of skin of nose | D48.5Neoplasm of uncertain behavior of skin | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Unspecified malignant neoplasm of skin of nose is a billable ICD-10-CM diagnosis code (C44.301). | Neoplasm of uncertain behavior of skin is a billable ICD-10-CM diagnosis code (D48.5). |
| Includes | malignant neoplasm of sebaceous glands malignant neoplasm of sweat glands | Neoplasm of uncertain behavior of anal margin Neoplasm of uncertain behavior of anal skin Neoplasm of uncertain behavior of perianal skin Neoplasm of uncertain behavior of skin of breast |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources