A squamous cell carcinoma that arises from the mucosal epithelial surface of the ethmoid sinus. Patients may present with nasal fullness, obstruction, and/or epistaxis. The disease is ethmoid sinus squamous cell carcinoma (MONDO_0002416). Also known as: epidermoid carcinoma of ethmoid sinus, epidermoid carcinoma of ethmoidal sinus, epidermoid carcinoma of the ethmoid sinus, epidermoid carcinoma of the ethmoidal sinus, ethmoid sinus epidermoid carcinoma, ethmoidal sinus epidermoid carcinoma, ethmoidal sinus squamous cell carcinoma, squamous cell carcinoma of ethmoid sinus.