###### C31 Malignant neoplasm of accessory sinuses
**C31.0 Maxillary sinus**

Antrum (Highmore)(maxillary)

**C31.1 Ethmoidal sinus**

**C31.2 Frontal sinus**

**C31.3 Sphenoidal sinus**

**C31.8 Overlapping lesion of accessory sinuses**

[See note 5 at the beginning of this chapter]

**C31.9 Accessory sinus, unspecified**