Mucocele in a spectacled owl (Pusilatrix perspicillata)

Case report: The first description of a thyroglossal duct cyst in a hen (Gallus gallus domesticus)

Thyroglossal duct cyst represents a congenital anomaly of the cervical region, rarely documented in animals. Although previously reported in dogs, cats, horses, goats, pigs, and calves, never in birds. This report describes a rare case of thyroglossal duct cyst in a hen. A necropsy of a Transylvanian Naked Neck hen carried following diphtheroid mucocutaneous lesions. The necropsy revealed a large, cyst-like structure measuring 0.5 cm at the level of the caudal edge of the left thyroid gland. Histologically, the cystic mass, bordered by 1-2 lines of well-differentiated ciliated cuboidal cells, presented nuclear immunoreactivity for Thyroid transcription factor 1. To the best of the authors' knowledge, there are no previous records of thyroglossal duct cysts in avians. Moreover, this is the first case describing a thyroglossal duct cyst in a hen.

Mucoepidermoid Carcinoma in the Skull of an Orange-winged Amazon Parrot (Amazona amazonica)

A 33-year-old female intact orange-winged Amazon parrot (Amazona amazonica) presented for a slowly growing mass over the right eye. A computed tomography scan performed with and without intravenous contrast revealed a heterogeneous mixed soft tissue and mineral-dense mass with a small area of non-contrast-enhancing fluid density located between the orbits at the caudal aspect of the nasal passages, with associated lysis of the right caudal nasal passage and the right frontal bone. Following euthanasia, the mass was found to consist of soft tissue between the right eye and nostril over the right frontal bone. Lysis of the underlying bone resulted in a bony defect leading into the infraorbital sinus along the dorsorostral aspect of the right eye. Histopathology revealed an unencapsulated, poorly demarcated, highly cellular neoplasm composed of islands and trabeculae of neoplastic cells embedded in abundant loose fibrovascular stroma which completely obliterated the cortical bone and sinuses of the rostral skull and infiltrated the surrounding muscle and soft tissue. Histologically, the tumor was consistent with a high-grade mucoepidermoid carcinoma, characterized by the presence of epidermoid, intermediate, and mucous-producing cell types. No evidence of metastasis was identified. The tissue of origin was suspected to be salivary or nasal mucous glands, but was difficult to confirm due to distortion of normal tissue architecture as a result of the tumor. Although mucoepidermoid carcinomas are a common salivary gland tumor in human medicine, they are not well recognized in avian species, and no specific case reports exist describing this pathology in an Amazon parrot. Despite the lack of distinct salivary glands in most avian species, mucoepidermoid carcinomas can occur, can cause significant clinical disease, and should be included as a differential diagnosis for avian patients presenting with similar lesions.