Ethmoid tumors in free-ranging white-tailed deer (Odocoileus virginianus).

This report describes a series of ethmoid tumors in 6, free-ranging white-tailed deer (Odocoileus virginianus; WTD) in southwest to central Texas, which included 4 plasma cell tumors, 1 adenosquamous carcinoma, and 1 adenocarcinoma. The plasma cell tumors had a distinctive presentation with unilateral to bilateral facial masses located rostromedial to the eyes that were smooth and fluctuant. Upon dissection, these preorbital facial masses consisted of multiloculated, mucus-filled, cystic pockets with 2 having partial extension of the ethmoid tumors into the external facial masses. The 2 carcinomas were larger, unilateral, solid facial masses. All tumors caused extensive destruction of the ethmoid region with the carcinomas being paler, firmer, and more invasive into surrounding areas compared with the plasma cell tumors. Ancillary testing did not reveal an underlying infectious cause, although these reports of multiple WTD across a localized region suggest a possible infectious, environmental, or other shared stimulus.