C50.3 (Malignant neoplasm of lower-inner quadrant of breast) compared with D48.6 (Neoplasm of uncertain behavior of breast), from the official CMS tabular data. C50.3 and D48.6 name the same anatomical site (breast) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (breast)
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. C50.3 and D48.6 name the same anatomical site (breast) with a different neoplasm behavior.
From the CMS 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.
| C50.3Malignant neoplasm of lower-inner quadrant of breast | D48.6Neoplasm of uncertain behavior of breast | |
|---|---|---|
| Billing status | Non-billable header | Non-billable header |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant neoplasm of lower-inner quadrant of breast is a non-billable ICD-10-CM category code (C50.3). | Neoplasm of uncertain behavior of breast is a non-billable ICD-10-CM category code (D48.6). |
| Includes | connective tissue of breast Paget's disease of breast Paget's disease of nipple | Neoplasm of uncertain behavior of connective tissue of breast Cystosarcoma phyllodes |
| Use additional code | code to identify estrogen, and other hormones and factors receptor status (Z17.-) | — |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources