D09.3 (Carcinoma in situ of thyroid and other endocrine glands) compared with D38.4 (Neoplasm of uncertain behavior of thymus), from the official CMS tabular data. D09.3 and D38.4 name the same anatomical site (thymus) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — uncertain behavior (thymus)
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. D09.3 and D38.4 name the same anatomical site (thymus) 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.
| D09.3Carcinoma in situ of thyroid and other endocrine glands | D38.4Neoplasm of uncertain behavior of thymus | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Carcinoma in situ of thyroid and other endocrine glands is a billable ICD-10-CM diagnosis code (D09.3). | Neoplasm of uncertain behavior of thymus is a billable ICD-10-CM diagnosis code (D38.4). |
| Includes | 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