C44.40 (Unspecified malignant neoplasm of skin of scalp and neck) compared with D04.4 (Carcinoma in situ of skin of scalp and neck), from the official CMS tabular data. C44.40 and D04.4 name the same anatomical site (scalp) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — carcinoma in situ (scalp)
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. C44.40 and D04.4 name the same anatomical site (scalp) 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.
| C44.40Unspecified malignant neoplasm of skin of scalp and neck | D04.4Carcinoma in situ of skin of scalp and neck | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Unspecified malignant neoplasm of skin of scalp and neck is a billable ICD-10-CM diagnosis code (C44.40). | Carcinoma in situ of skin of scalp and neck is a billable ICD-10-CM diagnosis code (D04.4). |
| Includes | malignant neoplasm of sebaceous glands malignant neoplasm of sweat glands | Bowen's disease erythroplasia grade III intraepithelial neoplasia Queyrat's erythroplasia |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources