Anatomopathological characterization of branchial cysts in slaughtered pigs.

Branchial cysts are a congenital anomaly in humans and other animal species. In this study, twenty commercially bred slaughtered pigs ranging from 120 to 150 days of age, sourced from different farms and lots, were found to have cysts in the oropharyngeal region at meat inspection despite the absence of clinical signs. Two cysts were selected for histopathological examination. The first cyst was surrounded by fibrous connective tissue and lined by a simple single cell layer of epithelium. The second cyst comprised a squamous pseudostratified to simple stratified epithelium, accompanied by a mild inflammatory infiltrate. This cyst was also surrounded by fibrous connective tissue and glands. The pathological diagnosis of branchial cysts in slaughtered pigs was established on the basis of their anatomical location and gross and microscopic findings.

Nasopharyngeal Presentation of a Pharyngeal Cleft Cyst in a Dog.

A 2 yr old castrated male shih tzu was presented for assessment of worsening chronic snoring since first detected at 3 mo of age. An upper respiratory endoscopic examination and a computed tomographic scan showed a well-circumscribed, fluid-filled nasopharyngeal mass located in the median plane on the nasal side of the soft palate. This lesion was removed using a ventral approach to the nasopharynx by blunt-sharp dissection from the submucosal tissues of the soft palate. Histopathology revealed a cystic lesion lined by a single layer of a pseudostratified columnar ciliated epithelium, characteristic of a pharyngeal cyst. Follow-up 5 mo after surgery revealed complete resolution of the clinical signs with no evidence of local recurrence. Pharyngeal cysts are developmental abnormalities of the branchial apparatus. Most derive from the second branchial arch and cause cysts, sinuses, and fistulae to develop in the neck region. In our case, the lesion was located in the nasopharynx, leading to snoring and exercise intolerance. This condition should be included in the differential diagnosis of suspected nasopharyngeal obstruction.

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.

Kystes bilatéraux de la deuxième fente pharyngée chez deux veaux d'un même élevage. Les kystes de la fente pharyngée (également appelés kystes de la fente branchiale) sont des anomalies congénitales rares de la région du pharynx qui apparaissent sous la forme de structures kystiques molles et fluctuantes sur le cou ventral. Ces kystes sont formés par une régression anormale des fentes pharyngées au cours du développement embryonnaire et sont bordés par un épithélium cylindrique pseudostratifié à squameux, partiellement cilié en histopathologie. Le développement de ces kystes est sporadique et aucun facteur de risque n'est actuellement identifié chez les espèces animales. Les kystes sont généralement unilatéraux et principalement diagnostiqués chez des animaux matures de diverses espèces. L'objectif de cet article est de rapporter deux cas de kystes bilatéraux de la deuxième fente pharyngée chez deux veaux sans pedigree partagé, localisés sur la même ferme. À la connaissance des auteurs, il s'agit du premier rapport de kystes de la deuxième fente pharyngée liés géographiquement chez les espèces vétérinaires, et des premiers cas de kystes bilatéraux chez les bovins.Message clinique clé :Les kystes de la fente pharyngée sont un différentiel important pour les structures molles, fluctuantes et kystiques sur le cou ventral de toutes les espèces. Ces cas sont généralement unilatéraux, diagnostiqués chez des animaux matures et sporadiques sans facteurs de risque actuellement identifiés chez les espèces vétérinaires.(Traduit par Dr Serge Messier).

A Branchial Cyst in a Diamond Python (Morelia spilota).

A 9-year-old female diamond python (Morelia spilota) was presented with a submandibular swelling. The cytological, macroscopic and histological features of this lesion indicated a diagnosis of branchial (pharyngeal) cyst. Branchial cysts are benign lesions caused by anomalous development of the branchial apparatus and are described rarely in veterinary medicine. We suggest that possible persistence of branchial remnants should be included in the consideration of differential diagnoses for neck masses in adult snakes.

Surgical Management of an Intrathoracic Branchial Cyst in a Yellow-crested Cockatoo (Cacatua sulphurea).

A 40-year-old, female lesser crested cockatoo (Cacatua sulphurea) was presented with a complaint of hyporexia and sudden onset of sneezing and wheezing. Physical examination revealed mild stertorous inhalation, and the apex of the heart was palpable caudoventral to the distal tip of the sternum. Projection radiographic images showed a soft tissue mass displacing the heart and the thoracic portion of the trachea. A subsequent computed tomography series revealed a single, large, and predominantly encapsulated soft-tissue mass. The mass was contained within the cranial thoracic region and occupied most of the anatomic location of the thoracic portion of the clavicular air sac, extending around a portion of the trachea. A surgical exploratory procedure was performed, with a thoracic inlet thoracotomy, and the mass was found to be cystic and deeply attached to surrounding tissues at its caudal-most aspect. Complete excision was not possible, and the mass was drained and an incomplete resection was accomplished with approximately one-half of the cystic structure removed and submitted for histopathology. The mass was found to be benign, epithelial-lined, dense, fibrous connective tissue that would be consistent with a branchial cyst.

Branchial cyst in a dog.

A French bulldog was presented with a facial swelling. Histology revealed a branchial cleft cyst. The first attempt to treat by incision, aspiration and drainage was unsuccessful. A complete surgical excision of the mass using a CO2 Laser lead to a full recovery. The location, size and type of tissues were compatible with a first branchial cleft cyst Type II.

Transformation of a thymic branchial cyst to a carcinoma with pulmonary metastasis in a dog.

A 9-year-old, female neutered Dalmatian was evaluated for acute onset of dyspnoea. Thoracocentesis on presentation yielded 1300 ml sanguineous fluid, while thoracic radiology and ultrasonography showed a mixed-echoic cavitary cranial mediastinal mass, sternal lymph node enlargement and pleural effusion. Surgical exploration of the thorax revealed a multi-lobulated red/brown cranial mediastinal mass and multiple similarly coloured ovoid nodules within several lung lobes. Histopathology revealed thymic branchial cysts with neoplastic transformation and examination of the lung was consistent with metastasis. Despite initially recovering well, acute sepsis and pyothorax resulted in cardiac arrest 8 days postoperatively. This is the first veterinary report of neoplastic transformation of a thymic branchial cyst with pulmonary metastasis.

Branchial cysts in two Amazon parrots (Amazona species).

A 37-year-old yellow-crowned Amazon parrot (Amazona ochrocephala) and a 20-year-old red-lored Amazon parrot (Amazona autumnalis) each presented with a large mass localized on the lateral neck. With the first bird, there was no evidence of signs of pain or discomfort, and the bird prehended and swallowed food normally. The second bird showed signs of mild upper-gastrointestinal discomfort. Results of an ultrasound examination and aspiration of the mass on each bird revealed a cystic structure. A computed tomography performed on the second bird revealed a large polycystic mass connected to the pharynx by a lateral tract. During surgical resection, both masses were found to originate from the subpharyngeal area. Based on topography and the histopathologic and immunohistochemical results, the masses were determined to be a second branchial cleft cyst for the first case and a second branchial pouch cyst for the second case. In addition, a carcinoma was present in situ within the epithelium of case 1, and the cyst in case 2 was secondarily infected. Branchial cysts are uncommonly diagnosed in veterinary and human medicine. These 2 cases are the first documented in parrots and appear similar to second branchial cysts reported in adult humans.

Marsupialization and iodine sclerotherapy of a branchial cyst in a horse.

A 6-month-old Morgan colt was evaluated because of a 10-cm right-sided retropharyngeal swelling. The swelling was soft and moveable on examination, and palpation did not elicit signs of pain. Radiography revealed a large space-occupying mass ventral to the second cervical vertebra; ultrasonography revealed an anechoic fluid-filled structure with a well-defined hyperechoic capsule. Fine-needle aspiration yielded a viscous amber fluid. Cytologic evaluation indicated that the fluid was an exudate; anaerobic and aerobic bacterial culture did not yield any growth. Histologic examination of a portion of the cyst capsule revealed a connective tissue wall lined by pseudostratified columnar to cuboidal epithelium, consistent with a branchial cyst. The cyst wall was marsupialized to the skin, and iodine sclerotherapy was performed twice daily for 14 days, at which time forceps were introduced into the cyst and the cyst lining was removed. The site was allowed to heal by second intention, but 10 days later, the swelling recurred. An incision was made over the previous marsupialization site, and residual remnants of the cauterized cyst lining were removed with a forceps. The foal did not have any other complications during the subsequent 2 years. Branchial arch cysts are uncommon embryonic anomalies of horses, mice, cats, dogs, and cattle. Results suggest that marsupialization and iodine sclerotherapy may be a viable alternative to surgical excision in horses with branchial cysts; however, the entire cyst lining must be removed at the completion of sclerotherapy to prevent recurrence and abscess formation.

Branchial cysts in laboratory mice.

Large solitary cysts in the superficial tissues of the ventral neck are described in five laboratory mice of two inbred strains and one outbred line. The cysts were lined by cuboidal to columnar epithelium similar to that in branchial cysts reported in other animal species but distinct from the stratified squamous epithelium with prominent lymphoid tissue typical of branchial cysts in man. These findings suggest that the lesion referred to as a branchial cyst in animals differs slightly from the lesion of the same name in man.

Branchial cyst in a dog.

A 7-year-old spayed German Shorthaired Pointer was determined to have a branchial cyst in the subcutaneous tissues of the cervical/facial area. Treatment had been attempted by aspiration and placement of drains, but without success; the final diagnosis was made after microscopic examination of the wall of the excised cyst. The means by which fluctuant swellings in this region may be differentiated are anatomic location and examination of full-thickness biopsy specimens of cyst walls.

Thymic branchial cysts in the dog and cat.

Branchial cysts of the thymus were diagnosed in 15 dogs and 2 cats. The main clinical sign was dyspnea. Pleural effusion varied in degree from minimal to severe. In all animals, an encapsulated mass in the cranial mediastinal region was found to consist of multiple epithelial cysts embedded in a stroma of fibrous connective tissue, adipose tissue, and vessels. Surgical resection of the cysts was performed in 7 dogs; 3 dogs survived and were clinically normal for 18 to 36 months.

Branchial cyst in a heifer.

A branchial cyst in a heifer was removed surgically. Diagnosis was based on clinical signs, analysis of cyst contents, and histologic examination of the cyst wall. Biochemically, the cyst fluid resembled a transudate. The cyst lining consisted of nonciliated, pseudostratified columnar epithelium and pigmented, keratinized, stratified squamous epithelium. The embryologic origin was thought to be endoderm of the 2nd pharyngeal pouch and adjacent ectoderm.