Salivary gland basal cell adenocarcinoma: a report of cases in a cat and two dogs

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.

Histopathological Results of Mouth Lesions in Dogs and Cats from Colombia

Mouth-related neoplastic and non-neoplastic lesions are commonly found in dogs and cats, and their diagnosis and classification are important for treatment planning and prognosis. This retrospective study analyzed mouth-related lesions in dogs and cats between 2000-2019 from the animal pathology laboratory of the Universidad de Antioquia, Medellín, Colombia. A total of 640 mouth-related lesions affecting 572 dogs (89.4%) and 68 cats (10.6%) were reviewed. Lesions were classified as neoplastic or non-neoplastic. The average age for neoplastic lesions was 8.6 years in dogs and 6.4 years in cats, while for non-neoplastic lesions the average age was 7.7 years for dogs and 5 years for cats. Data was analyzed using descriptive statistical methods according to year and source of report, demographic information for the animal, location of the lesion, and diagnosis. Tissue origin and behavior were variables considered for neoplastic lesions. Melanoma was the most common neoplasia in dogs and squamous cell carcinoma was most common in cats. The most frequent non-neoplastic lesion in dogs was gingival hyperplasia, while in cats the inflammatory lesions showed a wide range of morphological diagnoses. This study described many pathological lesions affecting the oral cavity for both dogs and cats and provides useful epidemiological data for both pathologists and clinicians.

Clinical and CT sialography findings in 22 dogs with surgically confirmed sialoceles

Sialoceles are an uncommon canine salivary gland disease, and complete surgical resection is important for a positive outcome. Radiographic sialography has been described as a diagnostic test for presurgical planning; however, superimposition artifacts may limit the diagnosis and detection of all affected glands. Computed tomographic (CT) sialography is a promising technique for delineating the salivary gland apparatus. The aims of this retrospective, observational study were to describe clinical and CT sialographic findings in a group of dogs with confirmed sialoceles, to determine the sensitivity of CT sialography for detecting affected salivary glands using surgery as the reference standard and to determine interobserver agreement for CT sialographic assessments. Dogs were included if they underwent a CT sialography study followed by surgical resection of the diseased gland(s) and histopathological analysis. Computed tomography sialography studies of dogs with surgically confirmed sialoceles (n = 22) were reviewed by a European College of Veterinary Diagnostic Imaging (ECVDI)-certified radiologist and an ECVDI resident. Interobserver agreement was calculated using Cohen's kappa statistics. CT sialography results were compared to surgical findings to determine sensitivity. Contrast leakage was detected in 12 of 22 dogs (54.5%), with intrasialocele leakage being most frequently observed (7/12, 58.3%). There was substantial agreement (κ = 0.70) between reviewers identifying diseased glands, substantial agreement (κ = 0.62) on the diagnostic quality, and no to slight agreement (к = 0.13) in the detection of contrast leakage. The overall sensitivity of CT sialography to detect surgically confirmed diseased glands was 66.7% (95% confidence interval: 48.8-80.8). In conclusion, these findings support the use of CT sialography as an adjunct diagnostic test for treatment planning in dogs with sialoceles.

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%).

A Novel Technique for Partial V-shaped Zygomatic Arch Ostectomy for Excision of Zygomatic Salivary Glands in Dogs

The present study described a novel technique for a partial V-shaped ostectomy of the zygomatic arch (ZA) for surgical excision of the zygomatic salivary glands (ZSG) in dogs and addressed advantages and disadvantages related to this procedure. The study was conducted on 6 clinically healthy mongrel dogs. A 3-4 cm curvilinear transcutaneous incision was performed parallel to the dorsal margin of the ZA. An additional 2 cm vertical incision was performed perpendicular to the former one forming a T-shaped incision over the ZA. The skin, subcutaneous tissue, and periosteum over the ZA were dissected and reflected laterally. At 0.5 cm from the orbital ligament, a V-shaped segment from the ZA was resected using an electrical saw. The base of the V-shaped segment was 1.5 cm wide and its apex was 0.5 cm from the ventral margin of the ZA. A combination of sharp and blunt dissection was used to dissect and excise the ZSG from the surrounding tissues. The periosteal flaps were coaptated in a simple continuous pattern. The subcutaneous tissue and skin were closed as usual. The new approach was a feasible technique for the excision of the ZSGs without considerable postoperative complications in dogs. The novel V-shaped partial ostectomy of the ZA technique is reliable, satisfactory, and relatively less invasive for surgical excision of ZSGs in dogs. Further work should be conducted on clinical cases.

Basal cell adenocarcinoma on bulbar conjunctiva of third eyelid in a dog

An 8-year-old castrated Toy poodle presented with swelling and proptosis of the right third eyelid caused by an exophytic mass on the bulbar surface. Histologically, the mass was composed of stratified neoplastic basaloid cells, arranged in nests and interconnecting islands, which were mixed with tubular structures. Immunohistochemically, the basaloid cells were positive for p63 and cytokeratin (CK) 14, and the inner epithelial cells of the tubular structures were positive for CK7, CK8, and CK19. According to these findings, the mass was diagnosed as a basal cell adenocarcinoma. Although basal cell adenocarcinoma is rare in animals, it should be included in the list of differential diagnoses for superficial tumors of bulbar conjunctiva of third eyelid in dogs.

External beam radiotherapy for the treatment of feline salivary gland carcinoma: six new cases and a review of the literature

CASE SERIES SUMMARY

Salivary gland carcinoma is uncommon in cats. We report the outcome of radiation therapy in six cases (four salivary gland adenocarcinomas, one tubulopapillary adenocarcinoma, one carcinoma). Five were treated after surgical excision of the primary tumour, but four had gross disease (primary or metastatic) at the time of starting radiotherapy. Exact progression-free interval from the start of radiotherapy in the two cats where this was known was 120 and 144 days, respectively. One cat was signed off at 766 days with no evidence of recurrence. Another cat was in remission at 202 days (when last seen by the referring practice) but subsequently developed recurrence (date uncertain). Survival time was known for three cats (55 days, 258 days and 570 days from initiation of radiotherapy, respectively). In two cases, locoregional progressive disease (PD) was confirmed, and the other presumed as the cause of death. Two cats, known to have developed PD, were alive at the time of writing (at 206 and 549 days, respectively). No cat died as a result of distant metastatic disease.

RELEVANCE AND NOVEL INFORMATION

There is a paucity of information on the treatment of salivary gland tumours. In humans, as in cats, there is no optimised standard of care for malignant tumours. It is accepted that, for surgical candidates (even with large tumours), surgery and radiotherapy is superior to radiotherapy alone. However, the benefits of postoperative radiotherapy compared with surgery alone are only clear in patients with high-risk tumours (ie, those with large and invasive primary tumours, close or incomplete margins, high histopathological grade, histological evidence of neural or vascular invasion, or positive lymph nodes). This population is analogous to the population reported here, and likely to most cats presented in practice. Thus, radiation therapy may help improve locoregional control and survival in cats.

Basal cell adenocarcinoma in the gland of the third eyelid of a brown bear (Ursus arctos)

The right third eyelid of an adult female brown bear (Ursus arctos) was swollen and removed. Histopathology revealed a tumor exhibiting proliferation with mild infiltration, consisting of multi-stratified glandular structures of the innermost laminal neoplastic cells and the basaloid neoplastic cells, and with eosinophilic thick basal lamina material around the glandular structures. Both types of neoplastic cells exhibited moderate anisokaryosis, and mitotic figures were observed in the basaloid neoplastic cells. The laminal neoplastic cells were cytokeratin (CK) 8/18-positive. In contrast, the basaloid neoplastic cells were CK14- and p63-positive, but α-smooth muscle actin- and calponin-negative. The case described herein is the first report of basal cell adenocarcinoma in the gland of the third eyelid of a bear.

Salivary Gland Epithelial-Myoepithelial Carcinoma with High-Grade Transformation in a Dog

An 8-year-old male neutered standard dachshund was presented with a slowly growing mass in the left submandibular salivary gland. Histopathological examination revealed a tumour that was composed of bilayered duct-like structures with an inner layer of ductal cells and an outer layer of clear cells. Both inner and outer cells in the greater part of the tumour exhibited low to moderate atypia and low mitotic activity. However, a focal area towards the periphery showed enhanced cellular atypia and mitotic activity in tumour cells. Immunohistochemically, the outer layer of clear cells expressed myoepithelial markers, while the inner layer cells were positive for a luminal epithelial marker. No local recurrence or lymph node or distant metastasis was observed 18 months following surgery. Based on the morphology and immunohistochemical findings, a final diagnosis of epithelial-myoepithelial carcinoma with high-grade transformation was made.

Cytological Diagnosis of Mandibular Salivary Gland Adenocarcinoma in a Dog

A case of mandibular salivary gland adenocarcinoma in a 9-year-old female dog is described. Material collected by fine needle aspiration underwent cytological examination and after the diagnosis of salivary carcinoma the mass was surgically excised and then was processed for histological examination. The aim of this work is to describe the cytopathological features of this carcinoma and to emphasize the usefulness of fine needle aspiration technique, which is an effective, inexpensive and minimally invasive method of diagnosis that can be performed before incisional biopsy or even before surgical excision.

First cases of animal diseases published in 2005

In 2003, Veterinary Quarterly started with the publication of a series of articles reviewing reports on "first cases" of animal diseases. Till now six articles have been published. They were arranged in order of animal species. Each article concerned only one species. Starting at this seventh publication, each article discusses "first cases" on more than one animal species. In this article 15 cases published in 2005 are discussed: one in birds, two in cats, three in cattle, four in dogs, two in goats, one in hares, and two in horses. Of each case a short introduction, the bibliographical data of the publication, the abstract of the author(s) (except one case) and some additional information (mainly) derived from the article are given.