Maxillary sinus cysts in two cattle.
Two adult Holstein cattle were found to have unilateral maxillary sinus cysts. One had dyspnea and partial airway obstruction; the other had a swelling over the sinus. Both had a nonfetid, mucoid nasal discharge. Deviation of the nasal septum away from the cyst, soft-tissue opacity involving the left maxillary sinus, and a gas-capped fluid line on lateral projection were identified radiographically. The cyst fluid did not have an odor, was relatively acellular, and was of a mucoid (animal 1) or gelatinous (animal 2) nature. In 1 animal, the cyst wall and fluid were removed through a dorsolateral bone flap. The owner reported that the animal improved rapidly and remained clinically normal 27 months after surgery. In the second animal, the cyst was drained and the cyst lining was curetted through a trephine hole in the sinus. The animal improved, but was euthanatized 4 days after surgery because of concurrent problems (displaced abomasum, poor milk production) and financial constraints of the owner. The cyst walls were composed of granulation tissue and were line with stratified squamous epithelium.