C12 (Malignant neoplasm of pyriform sinus) compared with D00.08 (Carcinoma in situ of pharynx), from the official CMS tabular data. C12 and D00.08 name the same anatomical site (fossa) with a different neoplasm behavior. MedCoder-derived
Same anatomical site, different neoplasm behavior.
Same site — carcinoma in situ (fossa)
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. C12 and D00.08 name the same anatomical site (fossa) 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.
| C12Malignant neoplasm of pyriform sinus | D00.08Carcinoma in situ of pharynx | |
|---|---|---|
| Billing status | Billable | Billable |
| Classification | C00-D49 — Neoplasms | C00-D49 — Neoplasms |
| Definition | Malignant neoplasm of pyriform sinus is a billable ICD-10-CM diagnosis code (C12). | Carcinoma in situ of pharynx is a billable ICD-10-CM diagnosis code (D00.08). |
| Includes | Malignant neoplasm of pyriform fossa | 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) | 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