Angiofibroma of the Nasal Cavity in a Dog: Case Report.

Nasopharyngeal angiofibroma is a histologic benign but locally aggressive vascular tumor described in humans. The description of this disease in dogs is limited. A mixed-breed female dog was presented with a history of epistaxis and nasal discharge. Rhinoscopy and computed tomography revealed a soft-tissue mass obstructing the entire nasal cavity, choana, maxillary recess, and right frontal sinus, but there was no bone or lymph node involvement. Histopathologic evaluation revealed irregular groups of blood vessels within a stroma of connective tissue, with secondary inflammation. Immunohistochemistry showed strong vimentin staining, mild factor VIII-related antigen staining, and negative staining for S100. The patient underwent tumor resection with fenestration surgery through the right maxillary bone, and there was tumor recurrence one year after surgery. This case report describes new findings regarding the immunohistochemical evaluation of nasopharyngeal angiofibroma in a dog. The laboratory and imaging findings, associated with a long-term follow-up, reinforce similar features between human and canine angiofibroma and may serve as a basis for immunohistochemical evaluation of this tumor in dogs.

Nasopharyngeal nephroblastoma in a 3-month-old Boer goat.

A 3-mo-old, female Boer goat was presented because of respiratory difficulties. Tachypnea and inspiratory dyspnea were noted during physical examination. Thoracic radiographs were unremarkable; however, upper airway and nasal passage radiographs revealed a soft tissue mass within the nasal passages. The patient underwent cardiorespiratory arrest and did not respond to resuscitation efforts during endoscopy. A large, pedunculated, semi-firm mass originated from the soft palate and obstructed 90% of the nasopharynx on autopsy. Histologically, the mass was composed of primitive cells that multifocally formed tubules and glomeruloid structures intermingled with areas of fusiform and blastemal cells. The neoplastic cells were positive for cytokeratin (tubular and glomeruloid cells), vimentin (fusiform population and blastemal cells), and Wilms tumor 1 protein (glomeruloid structures) on immunohistochemistry, consistent with a triphasic nephroblastoma. To our knowledge, nasopharyngeal nephroblastoma has not been reported previously in any species.

Primary extracranial nasopharyngeal meningioma in a dog.

An 8-year-old Labrador Retriever was presented for inspiratory efforts with stertor. A rhinoscopy and a magnetic resonance imaging scan were performed and revealed a naso-pharyngeal mass. The mass was identified in the nasopharynx without meningeal extension. This mass was both T1- and T2-hyperintense, compared to normal brain parenchyma without significant postcontrast enhancement. The mass was surgically removed and the histologic diagnosis was a mesenchymal tumor. Immunohistochemistry with antibodies was conducted and consistent with an extracranial meningioma. To the authors' knowledge, this is the first case report documenting a primary extracranial nasopharyngeal meningioma in a dog.

[Nasopharyngeal cyst of the respiratory epithelium in a 9-year-old Yorkshire terrier]. / Nasopharyngeale Zyste des respiratorischen Epithels bei einem 9 Jahre alten Yorkshire Terrier.

In a 9-year-old Yorkshire terrier a cyst of the respiratory epithelium of the nasopharynx was diagnosed. A complete obstruction of the nasopharynx leading to dyspnea was detected by computed tomography and endoscopy. A minimally invasive ablation of the cystic wall was performed under endoscopic guidance, followed by a pathohistological examination. Immediately after resection of the cyst, the clinical symptoms resolved. The follow-up endoscopical examination 3 months postoperatively was unremarkable. In the presented case the minimally invasive endoscopic ablation of the cystic wall was a successful treatment method.

Malignant peripheral nerve sheath tumour in the nasopharynx of a cow.

This case describes the findings in a Swiss Braunvieh cow with a malignant peripheral nerve sheath tumour (MPNST) in the nasopharynx. The major clinical signs were mixed dyspnoea with inspiratory and expiratory noises. Radiographic views of the head revealed an irregular mass with soft-tissue density in the nasopharynx originating from the dorsal pharynx and occupying and restricting the pharyngeal cavity. Endoscopic examination showed a lobulated mass obstructing almost the entire lumen of the aboral nasal passages and nasopharynx. Postmortem examination revealed a lobulated mass in the choanae with a broad attachment to the dorsal pharynx and histologically a soft tissue sarcoma with tumour cells positive for the S-100 and p75NTR (neurotrophin receptor) proteins and negative for CNPase. Electron microscopic examination showed few structures that indicated that the tumour originated from Schwann cells.

Comparison of standard radiography and computed tomography in 21 dogs with maxillary masses.

Imaging of patients with oral cancer is required to determine tumor extension in order to assist in prognosis and surgical planning. Conventional screen-film radiography (SFR) used to be the most common method for oral assessment, but computed tomography (CT) has become more available and is being used for obtaining complementary information. CT examinations eliminate superimposition by acquiring cross-sectional images of the region of interest. The objective of this study was to determine the diagnostic value of SFR compared with CT examinations for evaluation of oral masses in dogs. Twenty-one dogs received head and thorax SFR, and pre- and post-contrast head CT. Bony changes were observed in 80.9% and 95.2% of the cases in SFR and CT studies, respectively. Invasion of adjacent structures (i.e. nasal cavity, frontal and sphenoidal sinuses, orbit, maxillary recess, nasopharynx) was observed in only 30% of cases with SFR while CT showed 90.4% involvement. CT is an important preoperative examination modality and is more effective in identifying bone changes and tumor invasion of adjacent structures compared with SFR.

Nasopharyngeal disease in cats: 1. Diagnostic investigation.

PRACTICAL RELEVANCE: Nasal discharge, sneezing and upper respiratory noise are frequent presenting signs in feline practice. CLINICAL CHALLENGES: The small nasal cavity of the cat can make visualisation of lesions challenging. In addition, investigations may identify only secondary complications of a disease process, rather than the initial aetiological agent. GLOBAL IMPORTANCE: Nasopharyngeal disease is a worldwide problem. However, fungal disease shows regional variations in prevalence. AUDIENCE: This review, aimed at general practitioners as well as those undertaking more specialist investigations in feline respiratory disease, aims to provide practical guidance on the approach necessary to obtain a diagnosis in cats with nasopharyngeal disease. It should also help to explain why a specific diagnosis may not always be possible. EQUIPMENT: While access to endoscopy and computed tomography is advantageous, extensive information can be gained from equipment readily available in all practices. EVIDENCE BASE: The information presented in this article is based on peer-reviewed publications and the clinical experience of the authors.

Squash-preparation cytology from nasopharyngeal masses in the cat: cytological results and histological correlations in 30 cases.

Upper airway obstruction in cats can be a life-threatening condition. Early recognition of clinical signs and an appropriate diagnostic approach increases the possibility of appropriate therapeutic choices. The purpose of this study was to assess the efficacy and diagnostic value of squash-preparation cytology in providing an accurate diagnosis of masses growing in the nasopharynx of cats. Cytological specimens prepared by a squash technique from nasopharyngeal masses in 30 cats were collected under direct endoscopic guidance and classified into four groups: benign inflammatory/hyperplastic mass, lymphoma, carcinoma and sarcoma. The cytopathological diagnosis was compared with the final histopathological diagnosis and indices of diagnostic test accuracy were calculated. The results showed good agreement between the cytological and histological diagnosis with a sensitivity of 0.94, a specificity of 0.81, a positive likelihood ratio of 0.9, a negative likelihood ratio of 0.9 and an overall accuracy of 0.9. Squash-preparation cytology is considered an accurate diagnostic tool for distinguishing benign from malignant nasopharyngeal masses in cats. For differentiation of lymphoma and lymphoid reactions histopathological confirmation is recommended.

Nasal and nasopharyngeal lymphoma in cats: 50 cases (1989-2005).

Lymphoma is the most common nasal cavity tumor in cats, yet few reports specifically address the anatomic, immunohistologic, and cytologic features of this neoplasm. Fifty cats were diagnosed with lymphoma at necropsy, via biopsy or by cytology alone. Ten cats displayed multiorgan involvement, and in 2 of these the involvement was limited to the cerebellum and frontal cortex, respectively. Of the tumors, 41 of 50 (82%) were classified as nasal lymphoma, 5 of 50 (10%) were classified as nasopharyngeal lymphoma, and 4 of 50 (8%) involved both nasal and nasopharyngeal tissue. Histologically, all were considered diffuse lymphoid neoplasms and no cats displayed features of follicular lymphoma. Of the 44 cases available for slide review by the pathologist, 40 of 44 (91%) were classified as immunoblastic lymphoma, 2 of 44 (5%) as diffuse large cell, and 1 as diffuse mixed; 1 was unclassified. Of the 45 cats for which immunohistochemical stains were available, 32 were uniformly positive for CD79a, 7 were uniformly CD3 positive, and 6 had a mixed population of CD79a and CD3 cells. Epithelioptropism was exhibited in 4 of 5 (80%) cats in which there was sufficient epithelium present for evaluation. Of those 4, 3 were B-cell and 1 was a granulated T-cell lymphoma. In the 21 cats which nasal cytology was performed, 15 were cytologically diagnosed with lymphoma; the diagnoses in the remaining five cats were inflammatory (n = 4), normal lymphoid tissue (n = 1), or nondiagnostic (n = 1). The most common biochemical abnormalities were panhyperproteinemia in 26/46 (57%) of cats and hypocholesterolemia in 11/46 (24%) of cats.

Embryonal rhabdomyosarcoma in an immature Baird's tapir (Tapirus bairdii).

An immature Baird's tapir (Tapirus bairdii) with a history of seizure-like episodes developed signs of respiratory disease. The initial clinical diagnosis was pneumonia, and antibiotic therapy was started. The animal failed to improve after 14 days of therapy and developed unilateral, bloody nasal discharge. Endoscopic examination and radiography revealed a soft tissue mass in the nasopharynx depressing the soft palate. The tapir died 32 days after initial presentation. Histologic examination of the mass demonstrated a mesenchymal tumor composed of spindle cells with elongate nuclei forming densely packed fascicles. The neoplastic spindle cells showed prominent cross-striations. Immunohistochemistry revealed the cells to be positive for desmin and myoglobin, but negative for smooth muscle actin, confirming diagnosis of rhabdomyosarcoma. Embryonal rhabdomyosarcoma is the most common nasopharyngeal soft tissue tumor of humans, and it has been reported infrequently in dogs, horses, and pigs. Neoplasia should be a differential diagnosis in cases of unilateral nasal discharge and inspiratory stridor, even in young animals.

Clinical and magnetic resonance imaging features of nasopharyngeal lymphoma in two cats with concurrent intracranial mass.

Lymphoma is reported to be the most common nasal and second most common intracranial neoplasm in cats. Intracranial lymphoma may occur as a primary central nervous system lymphoma or as part of multi-centric disease. Two cats were presented with histopathologically confirmed nasopharyngeal lymphoma and concurrent mass within the middle fossa of the cranial cavity, with magnetic resonance imaging suggestive of direct communication. Both cats demonstrated evidence of bilateral oculomotor nerve deficits and upper respiratory tract noise. In one cat, bilateral optic nerve deficits were also present. The magnetic resonance imaging features were similar in both cases and demonstrated a contrast-enhancing intracranial mass on the ventral aspect of the middle fossa of the cranial cavity and an adjacent mass arising from the dorsal aspect of the nasopharynx. Lymphoma should be included as an important differential diagnosis in cats presented with middle cranial fossa syndrome (in particular ophthalmoplegia) and stertor.

Intralesional cisplatin chemotherapy and topical cryotherapy for the control of choanal squamous cell carcinoma in an African penguin (Spheniscus demersus).

A 3.5-yr-old, 2.5-kg female African penguin (Spheniscus demersus) was diagnosed with a choanal squamous cell carcinoma on the basis of biopsy after a history of choanal ulceration and anorexia with weight loss. Therapeutic modalities included the use of intralesional cisplatin followed by localized, topical cryotherapy with liquid nitrogen. The penguin remained free of clinical disease for a period of 9 mo, at which time a second cryotreatment was performed. The patient has remained free of all signs of choanal carcinoma for a period of 13 mo since the second cryotreatment.

Ribonucleotide reductase inhibitors enhance cidofovir-induced apoptosis in EBV-positive nasopharyngeal carcinoma xenografts.

In nasopharyngeal carcinoma (NPC), Epstein-Barr virus (EBV) infection is mainly latent, and the tumor cells contain episomal viral DNA. We have shown that the acyclic nucleoside phosphonate analog, cidofovir [(S)-1-(3-hydroxy-2-(phosphonylmethoxypropyl))cytosine] (HPMPC), inhibits growth of NPC xenografts in nude mice by causing apoptosis. The ribonucleotide reductase (RR) inhibitors, hydroxyurea and didox (3,4-dihydroxybenzohydroxamic acid), have been demonstrated to inhibit neoplastic growth and are used as antiviral and anticancer agents. Here we show that RR inhibitors enhance the antitumor effect of cidofovir in EBV-transformed epithelial cells. MTT assays indicate that hydroxyurea and didox enhance cidofovir-induced cell toxicity in NPC-KT cells, an EBV-positive epithelial cell line derived from NPC. The effect is due to enhancement of apoptosis through the caspase cascade as shown by pronounced cleavage of poly(ADP-ribose) polymerase. Finally, hydroxyurea strikingly enhanced the cidofovir-induced growth-inhibitory effect on NPC grown in athymic mice. The results suggest that RR inhibitors should enhance the antitumor effect of acyclic nucleoside phosphonate analogs on NPC.

The utility of megavoltage computed tomography images from a helical tomotherapy system for setup verification purposes.

PURPOSE: To evaluate the utility of relatively low-dose megavoltage computed tomography (MVCT) images from a clinical helical tomotherapy system for setup verification purposes. METHODS AND MATERIALS: Cross-sectional kilovolt computed tomography (kVCT) images were obtained for treatment planning purposes on a diagnostic third-generation CT scanner, followed by MVCT images from a helical tomotherapy system in 8 pet dogs with spontaneously occurring tumors. The kVCT and MVCT images were aligned for setup verification purposes, allowing repositioning before treatment delivery. RESULTS: Tumors are readily visualized on the MVCT images. At a dose of 2-3 cGy, the MVCT images are of sufficient quality for verification of treatment setup, but soft-tissue contrast is inferior to that with conventional kVCT. The MV and kVCT images were successfully aligned. When necessary, patients undergoing helical tomotherapy were repositioned before treatment. CONCLUSIONS: Megavoltage CT image quality is sufficient for tumor identification and three-dimensional setup verification in dogs with spontaneous tumors. The MVCT images can be aligned with the planning kVCT to ensure proper patient registration before treatment. Image alignment was successful in these canine patients, despite no skin markings defining patient positioning between the two scans. MVCT images facilitate setup verification, and their tomographic nature offers improvements over conventional portal imaging.

Cobalt radiation with or without low-dose cisplatin for treatment of canine naso-sinus carcinomas.

The objective of this study was to determine if low-dose cisplatin could be added safely to radiation therapy for the treatment of naso-sinus carcinomas in dogs. Thirty-one dogs were evaluated; 18 of these dogs received cobalt radiation in combination with low-dose cisplatin while 13 dogs received radiation alone. No difference was observed for acute or late radiation effects. Cisplatin was administered at a dosage of 7.5 mg/m2 20 min prior to every other radiation treatment. An initial dose of 10 mg/m2 was intended but toxicity (primarily azotemia) was unacceptable. Cisplatin was administered as prescribed in 12 of 18 dogs. Cisplatin was discontinued in 2 dogs because of azotemia. In the other 4 dogs cisplatin was not administered as prescribed because the dogs were withdrawn from treatment due to disease progression or radiation effects. There was no long-term renal disease in patients who developed azotemia. The overall median survival was 433 days with 4 (12.9%) dogs still alive at the completion of the study.

Feline inflammatory polyps: historical, clinical, and PCR findings for feline calici virus and feline herpes virus-1 in 28 cases.

Inflammatory polyps are associated with significant aural or nasopharyngeal disease in cats. It has been proposed that chronic viral infection may induce the masses. Ventral bulla osteotomy (VBO) is usually recommended for definitive therapy but removal of masses from the nasopharynx or external ear canal by traction/avulsion is also used. A retrospective study of 28 cats with inflammatory polyps was conducted to correlate recurrence with mode of therapy. Tissues from 41 polyps were assayed for feline calicivirus and feline herpesvirus-1 by RT-PCR and PCR, respectively. Of the 14 cats initially treated by traction/avulsion, recurrence was detected in five of nine cats with radiographic evidence of bulla disease but none of the cats with normal bullae. Traction/avulsion is a reasonable treatment for inflammatory polyps if the bullae are radiographically normal. Failure to detect feline calicivirus and feline herpesvirus-1 suggests that tissue persistence of these viruses is not associated with the development of inflammatory polyps.