Feline minor salivary gland adenocarcinoma: retrospective case series and literature review

CASE SERIES SUMMARY

Salivary gland adenocarcinoma, of major or minor salivary gland origin, is an uncommon tumor in cats. This article describes the clinical features, morbidity and survival rates of four cats with salivary gland adenocarcinoma arising from minor salivary gland tissue. Medical records from a private multicenter dentistry and oral surgery practice were reviewed for the period between 2007 and 2021. Four cats were included in this retrospective case series study, with oral masses on either the right or left caudal mandibular labial buccal mucosa. The inclusion criteria included a diagnosis of salivary gland adenocarcinoma in an anatomical location with lack of involvement of a major salivary gland, complete medical history and a follow-up of at least 6 months. The age range of the cats was 9-15 years; three of the cats were castrated males and one was a spayed female. Curative intent surgery was performed in three cats, whereas palliative surgery (debulking) owing to extensive soft tissue invasion was performed in one cat. Survival times were in the range of 210-1730 (mean 787) days. All four cats were euthanized owing to local recurrence and decreased quality of life, regardless of treatment modality.

RELEVANCE AND NOVEL INFORMATION

There are limited documented studies reporting the prevalence of salivary gland neoplasia affecting minor disseminated glands in the oral cavity of feline patients. Salivary gland adenocarcinoma should be a differential in cats presenting with caudal labial masses. Surgical resection has been the recommended treatment for salivary gland neoplasia of major salivary gland origin. According to this current case series, we propose that early aggressive surgical treatment with wide surgical margins should be performed for cats with salivary gland adenocarcinoma of minor salivary gland origin. Surgery increased the quality and duration of life; however, each patient was euthanized owing to local recurrence and morbidity.

Partial parotid sialoadenectomy in a horse with parotid ductal carcinoma: Surgical description and case report

OBJECTIVES

To describe the surgical findings, histopathological features, and long-term outcome for a horse with parotid salivary carcinoma.

STUDY DESIGN

Case report ANIMALS: Twelve year old American Quarter Horse gelding.

METHODS

The gelding was presented for a 10 × 10 cm swelling below the base of the right ear. Ultrasonographic examination revealed a mass involving the right parotid salivary gland. Incisional biopsy was consistent with parotid carcinoma. The tumor was marginally excised. The lateral wall of the guttural pouch was excised with the mass and was reconstructed with a porcine small intestinal submucosal (SIS) sheet. Cisplatin beads were implanted in the wound bed prior to closure. Firocoxib (0.1 mg/kg orally, daily, every 24 h) treatment was initiated.

RESULTS

Postoperative complications included right-sided facial nerve paralysis, difficulty with deglutition of fibrous feeds, and surgical site dehiscence. Wound healing was achieved by second intention. Partial improvement in nerve function was observed within the first 6 months. At 12 months postparotidectomy, no sign of tumor reoccurrence or metastatic disease was present, and the gelding returned to work.

CONCLUSION

Partial parotid sialoadenectomy was performed with a favorable long-term outcome. Regional anatomic knowledge is crucial.

A retrospective study of salivary gland diseases in 179 dogs (2010-2018)

Salivary gland diseases are well characterized in human medicine but are uncommonly reported in dogs. Herein we describe the clinical and pathologic features of 179 canine salivary gland biopsy submissions to the Athens Veterinary Diagnostic Laboratory from 2010 to 2018. The mean age of affected dogs was 8.5 y; no sex or breed predisposition was evident. The main reason for sample submission was regional swelling (107 cases; 59.7%). Extraoral (major) salivary glands were affected in 125 cases (69.8%), and oral (minor) salivary glands were affected in 43 cases (24% of cases). The location of the lesion (extraoral or oral) was not specified in 11 cases (6.1%). The diagnoses included nonspecific sialoadenitis (89 cases; 49.7%), normal salivary gland (42 cases; 23.4%), neoplasia (36 cases; 20.1%), salivary gland lipomatosis (7 cases; 3.9%), necrotizing sialometaplasia (4 cases; 2.2%), and traumatic hemorrhage (1 case; 0.5%). Most cases of sialoadenitis (63 cases), neoplasia (23 cases), and lipomatosis (5 cases), as well as all cases of necrotizing sialometaplasia and the only case of traumatic hemorrhage, affected extraoral glands. Most neoplasms (32 cases, 88.8% of the tumors) were epithelial and malignant, followed by round cell tumors (2 cases; 5.5%), a carcinosarcoma (1 case; 2.7%), and a tumor of undetermined histogenesis (1 case; 2.7%).

Salivary neoplasia in dogs and cats: 1996-2017

Objective

The objectives of this study were to report the contemporary demographical information, provide the incidence of and to assess sex and breed predisposition of salivary gland neoplasia in dogs and cats.

Materials and Methods

Information was collected from cats or dogs with salivary neoplasia (cases) and controls from the 26 university veterinary teaching hospitals within the Veterinary Medical Data Base. A total of 56 dogs and 24 cats were identified as having been diagnosed with salivary neoplasia.

Results

The incidence of salivary neoplasia in this population was calculated to be 15.3 per 100,000 dogs and 26.3 per 100,000 cats. The specific anatomic location of the salivary neoplasia was unable to be determined in 90.8% of cases in both dogs and cats. Results of the univariable conditional logistic regression models revealed no increased risk of salivary neoplasia in dogs or cats of any sex or neuter status (dogs: p = .26; cats: p = .45). There was no breed disposition within the feline species for salivary neoplasia. However, in the conditional logistic regression for dogs, poodles (toy and standard) trended towards significance (p = .075) with an odds ratio of 6.83 (95% CI: 1.16–40.10) compared to mixed breeds.

Conclusions and clinical relevance

The present study's results differ from previous conclusions made in regards to predisposed breeds and tumour location. Additional epidemiological studies should be performed to help in determining risk factors for salivary gland neoplasia.

Salivary gland neoplasms in non-human primates: A case series and brief literature review

BACKGROUND

Salivary gland neoplasms are rare in non-human primates.

METHODS

Thirty-five years of pathology records were reviewed at the Southwest (SNPRC) and Yerkes (YNPRC) National Primate Research Centers. An in-depth literature search for salivary gland neoplasms in non-human primates was performed.

RESULTS

Seventeen salivary gland neoplasms (nine from SNPRC and YNPRC, eight from published literature) were identified. There were seven malignant, nine benign, and one of undetermined behavior identified in eight rhesus macaques, six baboons, a chimpanzee, a bonnet macaque, and a moustached tamarin. Parotid gland was the most frequent origin (n = 7), followed by mandibular (n = 4) or minor salivary glands (n = 2). Two animals with salivary gland adenoma had a history of prior radiation exposure.

CONCLUSIONS

Parotid glands are the most common origin for salivary gland neoplasms. Salivary gland neoplasms should be considered in the differential diagnoses of head and neck masses in non-human primates.

Parotid Salivary Gland Basal Cell Adenocarcinoma in a Big-eared Opossum (Didelphis aurita)

The opossum (family Didelphidae) is a marsupial endemic to the Americas. Apart from the South American short-tailed opossum (Monodelphis domestica) and the Virginia opossum (Didelphis virginiana), there is considerable lack of knowledge about the health and diseases of most opossum species. Among these, the big-eared opossum (Didelphis aurita) is found in Argentina, Brazil and Paraguay. Natural and experimental studies have shown this species to be susceptible to infectious agents with zoonotic potential and the animals may play a role in transmission of such agents. However, neoplasia appears to be uncommon in this species. We describe the gross, microscopical and immunohistochemical features of a parotid salivary gland basal cell adenocarcinoma in a free-living big-eared opossum. This case represents the first report of salivary gland neoplasia in opossums.

Zygomatic gland adenoma in a dog: histochemical and immunohistochemical evaluation

Orbital epithelial tumors in dogs are rare and most frequently malignant. Distinguishing their origin from the lacrimal or zygomatic gland is often challenging and is based mostly on tumor location. A case of adenoma involving the orbit in a 13-year-old, female, standard Schnauzer is reported. Histologically, the neoplasm was characterized by nests and cords of epithelial cells mostly forming small glandular structures. The origin of the tumor from the zygomatic gland was determined by histochemical characteristics (alcian blue pH 1 positive staining) of a small remnant of normal gland included within the tumor capsule. The benign nature of our finding was confirmed by follow-up information: 2 years after complete surgical removal of the mass no tumor recurrence or metastases was recorded.

Salivary duct carcinoma in five cats

Carcinomas of salivary gland ducts are described in five cats. The typical histological pattern was the formation of large cell aggregates resembling dilated ducts, often with central necrosis and a looping pattern. All tumours were labelled with antibody to cytokeratins (CKs) 5, 6, 8, 14, 17 and 19. Labelling of tumour cells with CK14 suggested basal cell differentiation. All tumours stained with Jack bean (Canavalia ensiformis) agglutinin (Con A); this is a feature of normal salivary gland ducts but is seen in other salivary gland tumours. Staining of tumour cells at the luminal surface of ductal structures with wheat germ (Triticum vulgaris) agglutinin (WGA) in the cat tumours was similar to that seen in ducts of normal cat salivary glands but occurs in other cat tumours. Other immunohistochemical staining results were unremarkable. 1999 Harcourt Publishers Ltd.

Naturally occurring mucoepidermoid carcinoma in the submandibular salivary gland of two mice

Mucoepidermoid carcinomas in two mice were investigated histologically, immunohistochemically and ultrastructurally. The neoplastic cells showed divergent differentiation into periodic acid-Schiff-positive mucous cells, keratin-positive squamous cells, and cells with both mucous granules and sheaves of tonofilaments. Gland formation and keratinization were not observed. At the periphery of tumour cell nests, some cells were immunolabelled for smooth muscle actin or contained concentrated thin filaments, and these observations were interpreted to indicate that murine mucoepidermoid carcinomas are associated with both myoepithelium and duct epithelium.

Parotid salivary gland adenocarcinoma with bilateral ocular and osseous metastases in a dog

A case of primary parotid salivary gland adenocarcinoma is described in a three-year-old entire female great dane. The presenting complaint was sudden onset blindness concomitant with the development of bilateral hyphaema and anterior uveitis. A soft-tissue swelling of the left subaural region and right forelimb lameness were also present. A definitive diagnosis of primary parotid salivary gland adenocarcinoma with bilateral ocular metastases was made on post mortem examination. Metastases were also present in the right proximal humerus, left and right prescapular lymph nodes, left axillary lymph node, left retropharyngeal lymph node, bronchial lymph nodes and all lung lobes.

Primary salivary gland neoplasia in three cows

Salivary gland neoplasms in cattle are rarely reported. Three parotid gland carcinomas from slaughter cows are described. Based on light microscopic and ultrastructural appearances the neoplasms were classified as pleomorphic carcinomas in Cows 1 and 2 and as a squamous cell carcinoma in Cow 3.