ICD-10-CM Code for Malignant Neoplasm of Anterior Two-Thirds of Tongue
The ICD-10-CM code for a malignant neoplasm of the anterior two-thirds of the tongue is C02.x, with the specific fourth digit depending on the exact subsite within the anterior tongue.
Anatomic Classification
The anterior two-thirds of the tongue is classified as part of the oral cavity (not the oropharynx), which is a critical distinction for proper coding 1. The oral cavity subsites specifically include the anterior two-thirds of the tongue, along with buccal mucosa, alveolar ridges, retromolar trigone, floor of mouth, and hard palate 1.
Specific ICD-10-CM Codes
The C02 category breaks down as follows for the anterior tongue:
- C02.0 - Malignant neoplasm of dorsal surface of tongue (anterior two-thirds)
- C02.1 - Malignant neoplasm of border (lateral aspect) of tongue (anterior two-thirds)
- C02.2 - Malignant neoplasm of ventral surface of tongue (anterior two-thirds)
- C02.3 - Malignant neoplasm of anterior two-thirds of tongue, part unspecified
- C02.4 - Malignant neoplasm of lingual tonsil (base of tongue - this is oropharynx, NOT anterior two-thirds)
Key Coding Considerations
The fourth digit must specify the exact anatomic subsite - whether the tumor involves the dorsal surface, lateral border, ventral surface, or is unspecified within the anterior two-thirds 2.
Common Pitfall to Avoid
Do not confuse the anterior two-thirds of the tongue (oral cavity, C02.x codes) with the base of tongue/posterior one-third (oropharynx, C01 code). The base of tongue is anatomically and prognostically distinct, with different lymphatic drainage patterns and treatment approaches 1.
Clinical Context
Anterior tongue cancers have a 50-60% rate of occult neck metastasis, which is significantly higher than other oral cavity subsites like the alveolar ridge or hard palate 1. This high metastatic potential influences staging and treatment decisions but does not change the primary site code assignment.