Marsupialization and sclerotherapy with povidone iodine and ethanol of a branchial remnant cyst in an Arabian filly

Ultimobranchial body cyst in an adult horse: clinical, histopathologic, and immunohistochemical features

A 9-y-old Mangalarga Marchador gelding was referred to a veterinary hospital because of a swelling on the upper right side of the neck. Ultrasound examination revealed a multilocular structure adjacent to the thyroid gland with low echogenic content suggestive of fluid. The mass was removed surgically. Histologically, the cystic cavities in the surgical sample were filled with abundant eosinophilic secreta and lined by cuboidal, segmentally ciliated, columnar epithelium with interspersed goblet cells. Segmental crowding of the multilayered lining of the cyst was noted. Immunohistochemistry suggested the presence of both C cells and follicular cells, given the positivity of the immunomarkers calcitonin and TTF-1, respectively. The histogenesis of ultimobranchial cysts is uncertain. Based on clinical, histopathologic, and immunohistochemical identification, the cystic structure in this case is compatible with an ultimobranchial body cyst.

Bilateral second pharyngeal cleft cysts in 2 calves on the same farm

Pharyngeal cleft cysts (also called branchial cleft cysts) are rare congenital defects of the pharynx region that appear as soft, fluctuant cystic structures on the ventral neck. These cysts are formed by anomalous regression of the pharyngeal clefts during embryonic development and are lined by pseudostratified columnar to squamous, partially ciliated epithelium on histopathology. Development of these cysts is sporadic, with no currently identified risk factors in veterinary species. The cysts are typically unilateral, and primarily diagnosed in mature animals of various species. The objective of this article is to report 2 cases of bilateral second pharyngeal cleft cysts in 2 calves with no shared pedigree, located on the same farm. To the authors' knowledge, this is the first report of geographically linked second pharyngeal cleft cysts in veterinary species, and the first cases of bilateral cysts in cattle. Key clinical message: Pharyngeal cleft cysts are an important differential for soft, fluctuant, and cystic structures on the ventral neck of all species. These cases are typically unilateral, diagnosed in mature animals and are sporadic with no currently identified risk factors in veterinary species.