Metastasis to ipsilateral medial retropharyngeal and deep cervical lymph nodes in 22 dogs with thyroid carcinoma.

OBJECTIVE: To determine the rate of nodal metastasis to the medial retropharyngeal (MRP) and deep cervical lymph nodes in dogs surgically treated for thyroid carcinoma. STUDY DESIGN: Retrospective study. ANIMALS: Twenty-two client-owned dogs. METHODS: Medical records between July 2015 and October 2019 at the Universities of Missouri and Florida were reviewed. Dogs that underwent thyroidectomy with concurrent elective MRP lymphadenectomy ± deep cervical lymphadenectomy were included. Tumor site, preoperative staging, and histopathological findings were recorded. RESULTS: Twenty-two dogs with 26 total thyroid carcinomas were included. Primary tumors were lateralized in 19 dogs, bilateral in two dogs, and bilateral and midline ectopic in one dog. All dogs underwent ipsilateral MRP resection, including bilateral resection in dogs with bilateral tumors. Three contralateral MRP lymph nodes were excised from dogs with unilateral carcinomas. Four deep cervical lymph nodes and one superficial cervical lymph node were excised. Metastases were identified in 14 lymph nodes in 10 of 22 (45%) dogs. All four excised deep cervical lymph nodes and one contralateral MRP lymph node were identified as metastatic. Size of deposit could be classified in 13 of 14 metastatic lymph nodes. Macrometastasis was detected in seven lymph nodes, micrometastasis was detected in one node, and isolated tumor cells were detected in five lymph nodes. CONCLUSION: Regional metastasis was common within the lymph nodes sampled in this population of dogs with thyroid carcinoma. CLINICAL SIGNIFICANCE: These results provide evidence to justify further exploration of a larger population to verify the rate of regional metastasis and determine the prognostic impact of nodal metastasis.

Primary pharyngeal alveolar rhabdomyosarcoma in an adolescent Japanese black heifer.

Alveolar rhabdomyosarcoma (ARMS) is a rare mesenchymal tumor with differentiation toward the skeletal muscle. Although several cases of canine ARMS have been reported in veterinary medicine, only one case of abdominal ARMS has been reported in a cow. A 13-month-old, Japanese black heifer was referred for pus-like nasal discharge. On autopsy, an 11 × 7 × 4.5-cm pedunculated mass closed to the left palatine tonsillar sinus that occupied the laryngopharynx. Histopathological and immunohistochemical analyses indicated that the tumor was a typical ARMS. To the best of our knowledge, this has been the first case of primary pharyngeal ARMS in a Japanese black heifer, which is rare among cows. Nonetheless, its characteristics, including site, age and subtype, are identical to those among humans and dogs.

Dynamic pharyngeal collapse in three cats with different pharyngeal pathology.

Dynamic pharyngeal collapse (PC) is a rarely reported condition in cats defined as the partial or complete collapse of the pharyngeal lumen during inspiration. Herein, we report the imaging findings and clinical features of three cats with dynamic PC. Lateral radiograph of the head was insufficient to detect dynamic PC, but fluoroscopy in conscious cats revealed dynamic PC. Magnetic resonance imaging was not helpful to reveal dynamic PC and underlying diseases. We obtained biopsy samples from the irregular nasopharyngeal mucosal membrane through endoscopy in two of the three cases and high-grade B-cell lymphoma was histopathologically diagnosed. In feline cases with abnormal upper respiratory sounds, dynamic PC should be considered, and fluoroscopy is the imaging technique of choice to diagnose the condition.

Piecemeal endoscopic polypoidectomy for the management of a canine pharyngeal hemangiosarcoma.

A 7-year-old castrated male Maltese dog was presented for increased respiratory sounds, inability to bark, dysphagia, and hyporexia. Radiographs revealed an ovoid, opaque mass in the caudal nasopharynx. An airway examination and computed tomography scan were followed by endoscopic polypoidectomy. The mass was a hemangiosarcoma, and the patient survived > 13 months.

Polypoïdectomie endoscopique fragmentaire pour la gestion d'un hémangiosarcome pharyngé canin. Un chien Bichon maltais mâle castré âgé de 7 ans a été présenté pour des sons respiratoires accrus, l'incapacité de japper, de la dysphagie et de l'hyporexie. Les radiographies ont révélé une masse ovoïde opaque dans le nasopharynx caudal. Un examen des voies respiratoires et une tomodensitométrie ont été suivis d'une polypoïdectomie endoscopique. La masse était un hémangiosarcome et le patient a survécu >13 mois.(Traduit par Isabelle Vallières).

Diagnostic accuracy of contrast-enhanced computed tomography for assessment of mandibular and medial retropharyngeal lymph node metastasis in dogs with oral and nasal cancer.

The diagnostic accuracy of contrast-enhanced CT for detection of cervical lymph node metastasis in dogs is unknown. The purpose of this retrospective, observational, diagnostic accuracy study was to assess the efficacy of CT for detection of mandibular and medial retropharyngeal lymph node metastasis in dogs. Histopathology of dogs with cancer of the head, CT and bilateral mandibular and medial retropharyngeal lymphadenectomy was reviewed. A single radiologist measured lymph nodes to derive short axis width and long-short axis ratios. Two blinded radiologists separately assessed lymph node margins, attenuation and contrast enhancement and each provided a final subjective interpretation of each node site as benign or neoplastic. Where radiologists' opinions differed, a consensus was reached. Sensitivity, specificity and accuracy were calculated for mandibular and medial retropharyngeal sites. Agreement between radiologists was assessed. Fisher's exact test and the Kruskal-Wallis H-test were used to assess associations between variables. Forty-one primary tumours were recorded in 40 dogs. Metastasis to mandibular or retropharyngeal lymph nodes occurred in 16 out of 40 dogs (43/160 nodes). Agreement between radiologists was almost perfect for margination, attenuation and enhancement, strong for interpretation of mandibular lymph node metastasis, and weak for interpretation of medial retropharyngeal lymph node metastasis. Sensitivity of CT was 12.5% and 10.5%, specificity was 91.1% and 96.7%, and accuracy was 67.5% and 76.3% for mandibular and medial retropharyngeal lymph nodes respectively. No individual CT findings were predictive of nodal metastasis. Given the low sensitivity of CT, this modality cannot be relied upon alone for assessment of cervical lymph node metastasis in dogs.

Squamous cell carcinoma in a wild European bullhead Cottus gobio.

A pharyngeal tumor was found in a wild European bullhead. The tumor mass appeared underneath the operculum and was bilobed. The major neoplastic component showed diffuse epithelial squamous differentiation. Crossmonn's trichrome allowed identification of connective tissues whereas no neoplastic cells were stained. Periodic acid-Schiff was negative within the mass, and Giemsa did not show any further diagnostic significance. Immunohistochemistry showed diffuse positive cytoplasmic staining of the neoplastic population with an anti-human pancytokeratin antibody. Vimentin was negative and exclusively stained the stroma. On the basis of the morphological and immunohistochemical results, a squamous cell carcinoma was diagnosed.

COMPUTED TOMOGRAPHIC FEATURES OF PHARYNGEAL NEOPLASIA IN 25 DOGS.

Computed tomography (CT) is commonly used to investigate head tumors in dogs, however little information is available for lesions of the pharyngeal area. The purpose of this multicentric, retrospective, cross-sectional study was to describe the CT findings in a sample of dogs with pathologically confirmed pharyngeal neoplasia and determine whether any CT features allowed differentiation of tumor type. Location of lesions, size and shape, margins, relationship with surrounding structures and vessels, attenuation characteristics and enhancement pattern, regional lymph node changes, and presence of metastasis were recorded by three observers (1 DECVDI). The effect of final diagnosis on each CT feature was tested. A total of 25 dogs were included: 15 with carcinomas, five sarcomas, four melanomas, and one lymphoma. The oropharynx and laryngopharynx were more frequently involved. Among tumor groups, lesions were of similar size, irregularly shaped, had ill-defined margins, and had moderate-to-marked heterogeneous contrast enhancement. Lysis of hyoid bones was recorded in two carcinomas and infiltration of the lingual artery occurred in one case. Marked medial retropharyngeal lymphoadenomegaly was recorded in 11 of 14 carcinomas, in all sarcomas and in two of four melanomas. The single lymphoma case showed ill-defined thickening of the oropharyngeal and laryngeal wall with retropharyngeal and mandibular lymphadenomegaly. Lung metastases were found in two of five sarcomas and two of four melanomas. Findings from the current study did not support the hypothesis that CT features could be used to predict pharyngeal tumor type in dogs. However, CT was helpful for determining mass extension, lymph node involvement, and distant metastatic spread.

[First detection of psittacid herpesvirus 2 in Congo African grey parrots (Psittacus erithacus erithacus) associated with pharyngeal papillomas and cloacal inflammation in Germany]. / Erste Nachweise des Psittacid Herpesvirus 2 bei Kongo-Graupapageien (Psittacus erithacus erithacus) mit papillomatösen Rachenveränderungen und Kloakenentzündungen in Deutschland.

Congo African Grey Parrots (GP; Psittacus erithacus erithacus) from four different avicultures, presented in the Clinic for Exotic Pets, Reptiles and Birds, University of Veterinary Medicine Hannover, Foundation, showed choanal papillomas or hyperemia of the cloacal mucosa. Histologically, the mucosal choanal proliferations were diagnosed as exophytic papillomas and a mild hyperplasia of the cloacal mucosa with lympho-histiocytic inflammation with no visible inclusion bodies was found. Herpesvirus genome was detected by nested PCR in pooled choanal and cloacal swabs from clinically diseased parrots and healthy contact animals. Sequencing of parts of the herpesvirus DNA-polymerase gene indicated 98-100% homology of the detected herpesviruses with the Psittacid Herpesvirus 2 (PsHV-2). In one aviculture with cloacal inflammation papillomavirus-DNA was concurrently found to a PsHV-2 infection. In addition to the four avicultures with clinical symptoms 25 more flocks of grey parrots, in total 57 Congo-GP and 13 Timneh-GP, were examined for a herpesvirus infection. A total of six out of 29 studied parrot avicultures were tested positive for PsHV-2. The detection of this virus also in flocks of GP, which were bred in Europe, shows the establishment of this infection in the GP population in captivity. As indicated in the literature as well as in our study PsHV-2 could be only detected in Congo-GP, independently if they were kept either alone or in mixed avicultures with amazon and macaw species. These findings suggest that PsHV-2 is adapted to this Psittacus species.

Diagnosis and treatment of a pharyngeal squamous cell carcinoma in a Madagascar ground boa (Boa madagascariensis).

A 15-yr-old female Madagascar ground boa (Boa madagascariensis) presented with a history of anorexia, wheezing, and occasional open-mouth breathing. On oral examination, a firm, caseous mass was noted in the right caudoventral pharyngeal region, which was confirmed as a carcinoma on incisional biopsy. Advanced imaging (computed tomography and magnetic resonance imaging) was performed to evaluate local tumor invasion and to plan for palliative radiation therapy. However, following the second treatment (10 Gy), the mass had increased in size, and the snake was euthanatized. Radiation-associated vasculitis was noted within the soft tissues surrounding the mass and within muscles and the lung, which was verified on histopathology. The squamous cell carcinoma of the snake in this report was resistant to palliative radiation therapy.

Pharyngeal odontoma in an adult walleye (Sander vitreus).

An adult walleye (Sander vitreus) was submitted to Cornell University for evaluation of a hard pale-tan pharyngeal mass attached to the gill arches. Dozens of hard white conical structures radiated from the surface. Microscopically, conical structures were identified as denticles and rested on plates of dysplastic orthodentine, cementum, and acellular bone. A diagnosis of compound odontoma was made based upon the presence of proliferative epithelial and mesenchymal odontogenic tissues that recapitulated tooth structures normally present on gill rakers. Odontomas are classified as hamartomas and typically develop in immature diphyodont mammals. The pharyngeal location and lifelong regeneration of teeth in fish, however, both qualify the present diagnosis in the pharyngeal region of an adult teleost. Ontogenic and morphologic differences between mammalian and piscine dentition and differentials for tooth-bearing tumors in fish are presented within the context of a developmental anomaly.

Disorders of the pharynx.

Pharyngeal disorders are complex and difficult to treat. Disorders that lead to anatomic derangement, such as trauma and neoplasia, can significantly affect the function of this organ. Pharyngeal dysfunction can manifest as dysphagia, persistent palatal displacement, or exercise intolerance. Secondary complications are serious and life threatening and include aspiration pneumonia, weight loss, and death. Pharyngeal disorders that are only recognizable during strenuous exercise are difficult to diagnose and are treated with limited success, even though they are responsible for significant economic losses with performance animals.

Aural-pharyngeal polyps associated with Cryptosporidium infection in three iguanas (Iguana iguana).

Cryptosporidium spp. infection was associated with aural-pharyngeal polyps in three iguanas (Iguana iguana). All iguanas were presented for masses protruding from the ear canal, and the disease was characterized by a chronic clinical course. The masses consisted of nests of cystic glands surrounded by abundant fibrous connective tissue and lined by hyperplastic cuboidal to pseudostratified columnar epithelium that was moderately to heavily colonized by cryptosporidial organisms. Electron microscopy revealed that the majority of organisms were trophozoites.

Lymphosarcoma of the pharyngeal region in a 7-month-old beef steer.

A steer presented for retropharyngeal swelling and dyspnea. Biopsy of the swelling indicated lymphoblastic lymphosarcoma, and necropsy revealed involvement of regional veins and arteries. The tumor was classified as a non-T, non-B lymphoma based on CD3 polyclonal antibody stains. Lymphosarcoma is unusual in this location, but should be considered with retropharyngeal swelling.

Squamous cell carcinoma of the larynx and pharynx in horses.

Medical records were reviewed for 11 horses with squamous cell carcinoma of the larynx and/or pharynx. The average age at presentation was 15.3 years. No breed or sex predilection was present. At presentation, 6 of 11 horses were dyspneic and 4 horses had inspiratory stridor. Endoscopy was performed in all cases and was more useful in demonstrating a mass in the laryngopharyngeal region than laryngeal or guttural pouch radiography. Surgical excision was attempted in 3 horses and in 1 horse alleviated clinical signs for 4 months. Ten horses were euthanatized and 1 horse died. Results of this study indicated that laryngopharyngeal squamous cell carcinomas are difficult to surgically excise due to their location, size and invasiveness. Treatment is often not attempted because of the advanced state of the disease at the time of presentation.

Squamous-cell carcinoma of the pharyngeal cavity in a Jersey black giant rooster.

Squamous-cell carcinoma of the pharyngeal cavity was diagnosed in a 3-year-old Jersey black giant male chicken. Grossly, the carcinoma was round with irregular edges, yellow-tan, cauliflower-like with a crusty surface, and attached to the roof and sides of the pharyngeal cavity. Histologically, the surface of the mass was covered by a dense mat of necrotic mucosa and inflammatory cells. A broad front of neoplastic cords consisting of squamous epithelial cells extended into the lamina propria. There was no evidence of vascular invasion or metastasis.

An expansile secondary hypophyseal mastocytoma in a dog.

A 5-year-old mixed breed dog was presented with a history of depression and anorexia. Physical examination revealed a pharyngeal tumour and a neurological examination indicated the presence of a possible space-occupying lesion in the brain. Investigative procedures included a bloodsmear, impression smears and cytology of the pharyngeal tumour, haematology, chemical pathology, faecal analysis, urinalysis, electrocardiography, cerebrospinal fluid analysis, hormone assays and a computerised axial tomography scan. Results of these investigations revealed a round cell tumour in the pharynx, hypergammaglobulinaemia (34 g l-1), azotaemia (urea 8.6 mmol l-1 and creatinine 170 mumol l-1), hypoalbuminaemia (20 g l-1), proteinuria, sinus bradycardia (heart rate 60 beats per min), increased concentration of protein in the CSF (1.1 g l-1), hypoadrenocorticism (base line cortisol less than 55 nmol l-1) and hypothyroidism (T4 less than 13 nmol l-1). The computerised axial tomography scan revealed a brain tumour in the region of the hypophysis. The dog was euthanased and a post mortem examination confirmed the presence of a pharyngeal tumour with apparent direct extension of the tumour into the brain. Both tumours were confirmed histologically as mastocytomas.