ETHMOID ADENOCARCINOMA PERFORATING THE CRIBRIFORM PLATE IN THE HORSE

This clinical report describes an 8-year-old Thoroughbred mare that wa s presented for evaluation of a chronic, unilateral nasal discharge. F indings on physical examination, radiology, and video-endoscopy suppor ted a clinical diagnosis of ethmoidal hematoma. After surgical ablatio n of the mass a defect was detected in the cribriform plate. At necrop sy a 1.5 cm aperture was identified in the left cribriform plate allow ing direct communication between the fundus of the nasal cavity and th e cranium. Histology of the mass identified tissue consistent with an adenocarcinoma. History of profuse epistaxis warrants further investig ation to differentiate malignant lesions from the more common benign l esions. During surgical ablation of large, space-occupying masses of t he caudodorsal nasal cavity the cribriform plate should be examined fo r defects or secondary erosive lesions.