Surgical management of a subepiglottic thyroglossal duct cyst in a dog

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.

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.

A clinical case of a subepiglottic cyst in a Japanese Black calf

A 36-day-old Japanese Black calf exhibited wheezing associated with dyspnea from birth. Arterial blood gas analysis revealed a low oxygen partial pressure of 51 mmHg, low oxygen saturation of 83%, and high carbon dioxide partial pressure of 58.8 mmHg. Computed tomography, endoscopy, and ultrasonography showed cyst formation under the epiglottis. When the cyst was aspirated under ultrasonic guidance to secure the airway, 30 ml of viscous white turbid content was aspirated. The cyst shrank immediately after aspiration, but the wheezing and respiratory symptoms resumed 7 days after aspiration. Therefore, the cyst was surgically removed from the ventral side of the neck. No cyst remodeling was observed 30 days after surgical removal.

Cranial Mediastinal Thyroglossal Duct Adenocarcinoma in a Dog

A 7 yr old female spayed Canaan dog was presented for evaluation of a subclinical intrathoracic mass noted during meta-static staging for a digit and lingual mass. Thoracic ultrasound and computed tomography revealed a 6.0 × 5.5 cm mass within the cranial mediastinum. The mass was septated with mixed fluid and soft-tissue structures and no evidence of vascular invasion. Narrow excision of the mass via a sternal thoracotomy was performed. Histopathology of the mass was consistent with a thyroglossal duct cyst adenocarcinoma. This is the first reported case of a thyroglossal duct cyst adenocarcinoma arising in the cranial mediastinum of a dog. There was no evidence of metastasis or recurrence 25 mo after surgery and adjunctive therapy.

Videofluoroscopic Evaluation of the Pharynx and Upper Esophageal Sphincter in the Dog: A Systematic Review of the Literature

Background: Diseases of the pharynx and upper esophageal sphincter can result in debilitating respiratory difficulty, dysphagia or a combination of both. An exact diagnosis is essential to properly prognosticate and guide therapy. Videofluoroscopic assessment of the pharynx and upper esophageal sphincter with or without orally administered contrast material is the diagnostic of choice for many diseases as both anatomic and functional information is gleaned. The purpose of this review is to assess for continuity in imaging protocols across institutions and to record quantitative and qualitative parameters used for analysis of videofluoroscopy of the pharynx and upper esophageal sphincter in dogs.

Methods: A systematic literature search was performed including articles published in peer-reviewed veterinary journals involving the topic of videofluoroscopy of the pharynx and upper esophageal sphincter through August 1, 2018. Specifics of study acquisition technique were recorded. Quantitative and qualitative videofluoroscopic parameters were recorded and compared across institutions where appropriate using one-way ANOVA with p ≤ 0.05 being considered significant.

Results: Videofluoroscopy of the pharynx and upper esophageal sphincter is performed either in right lateral or standing postures depending on the institution. Bolus size and consistency used during contrast videofluoroscopy of swallowing differs between institutions. Some institutions evaluate videofluoroscopic studies using qualitative criteria while others apply quantitative measures. Reported quantitative measures include inter-swallow interval, swallow rate, jaw cycles per swallow ratio, time to upper esophageal opening, maximal pharyngeal contraction, maximum laryngeal excursion, upper esophageal closure, epiglottic re-opening, and pharyngeal constriction ratio. Measurement outcomes are significantly different between institutions and when bolus size/consistency is variable when assessing healthy dogs.

Conclusions: The current peer-reviewed literature on fluoroscopic evaluation of the pharynx and UES in dogs shows a lack of standardization regarding imaging protocol. There is not a standard set of quantitative criteria applied amongst the institutions and there are significant differences in the outcomes obtained from videofluoroscopic assessment of swallowing suggesting significant inter-observer or inter-institutional variability. A consensus statement regarding imaging protocol and what parameters should be used to interpret airway and swallowing videofluoroscopic studies of the pharynx and UES in dogs is needed along with targeted analysis of observer variability.

Thyroglossal Duct Carcinoma in a Cat

A 14 yr old castrated domestic shorthair cat presented for a fluid-filled structure in the ventral cervical region that had been present for 1 yr and had not resolved after repeated aspiration and drainage. Cervical computed tomography showed an approximately 10 cm, fluid-filled, multilobulated mass located on the ventrolateral right side of the cervical region extending into the thoracic inlet. Cytologic examination of the fluid revealed cystic fluid with evidence of chronic hemorrhage. The mass was surgically removed, and histopathologic examination revealed a thyroglossal duct carcinoma. Thyroid and parathyroid gland origin were ruled out by negative immunohistochemical staining for thyroglobulin, parathyroid hormone, calcitonin, and synaptophysin. No adjunctive treatment was performed and no recurrence was noted at 14 mo. Thyroglossal duct carcinoma has not been previously reported in a cat. There are two previous reports of squamous cell carcinoma of the thyroglossal duct in dogs. In humans, with complete removal and no evidence of metastasis, carcinoma of the thyroglossal duct has a good prognosis for recovery.