C78.39 (Secondary malignant neoplasm of other respiratory organs) compared with D02.1 (Carcinoma in situ of trachea), from the official CMS tabular data. C78.39 and D02.1 name the same anatomical site (cartilage) with a different neoplasm behavior.
Same anatomical site, different neoplasm behavior.
Same site — secondary malignancy (cartilage)
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. D02.1 and C78.39 name the same anatomical site (cartilage) 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.
| C78.39Secondary malignant neoplasm of other respiratory organs | D02.1Carcinoma in situ of trachea | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms (C00-D49) | C00-D49 — Neoplasms (C00-D49) |
| Definition | Secondary malignant neoplasm of other respiratory organs is a billable ICD-10-CM diagnosis code (C78.39). | Carcinoma in situ of trachea is a billable ICD-10-CM diagnosis code (D02.1). |
| Includes | — | Bowen's disease erythroplasia grade III intraepithelial neoplasia Queyrat's erythroplasia |
| Use additional code | — | code to identify: exposure to environmental tobacco smoke (Z77.22) exposure to tobacco smoke in the perinatal period (P96.81) |
Derived from the official CMS ICD-10-CM tabular data (FY2026). Not billing advice; verify sequencing rules for the encounter. All data sources