Mucocele in a spectacled owl (Pusilatrix perspicillata)

A 6-year-old breeding female spectacled owl (Pusilatrix perspicillata) was presented for a soft, fluid-filled, spherical mass under the neck that had been increasing in size over the previous 3 days. Results of a fine-needle aspirate of the mass showed clear, pale-yellow fluid with a total protein of 12.6 g/L. Cytologic examination revealed erythrocytes, moderate numbers of heterophils, and numerous foamy mononuclear cells against a mucoid background. Macroscopically, the mass appeared to be attached firmly to the esophagus. The mass was excised surgically and submitted for histopathologic examination. The lesion comprised a circumscribed, fibrous-encapsulated multilocular cyst, lined by plump, goblet-type, cuboidal epithelial cells lying in abundant mucinous matrix. Findings were consistent with a mucocele of the esophageal mucosal gland. Excision was considered curative based on follow-up 6 months after initial presentation. To our knowledge, this is the first report of this condition in Strigiformes and indicates that mucocele should be included in the differential diagnosis of cervical masses in birds.