ICD-10-CM>C00-D49>C30-C39>C31C31Malignant neoplasm of accessory sinusesNon-Billable/Non-SpecificCodesC31.0Malignant neoplasm of maxillary sinusC31.1Malignant neoplasm of ethmoidal sinusC31.2Malignant neoplasm of frontal sinusC31.3Malignant neoplasm of sphenoid sinusC31.8Malignant neoplasm of overlapping sites of accessory sinusesC31.9Malignant neoplasm of accessory sinus, unspecified