Dermoscopic features of benign sebaceous proliferations in dogs: Description, assessment and inter-observer agreement.

BACKGROUND: Dermoscopy is a useful, noninvasive technique also used to assess sebaceous lesions in humans. Sebaceous hyperplasia, sebaceous adenoma and sebaceous epithelioma are common cutaneous lesions in dogs; however, their dermoscopic features have not been investigated. HYPOTHESIS/OBJECTIVES: The objectives of this study are to describe the dermoscopic features of canine sebaceous lesions and to assess the interobserver agreement on dermoscopic parameters. ANIMALS: Thirty-four lesions excised from 17 client-owned dogs, histologically confirmed as sebaceous proliferations, were included in this study. MATERIALS AND METHODS: Sebaceous lesions were evaluated in vivo at ×10 magnification with a handheld dermoscope. Each dermoscopic image was assessed independently by two ECVD board-certified veterinary referral clinicians and an ECVD resident. RESULTS: Thirty sebaceous hyperplasias, two sebaceous adenomas and two sebaceous epitheliomas were included. Dermoscopically, most lesions (91%) had single or multiple, well-defined, white-yellowish structures composed of grouped ovoid areas (clods). Irregular linear and, less commonly, arborising vessels were detected at the periphery of the yellow lobular-like structures in 93% of sebaceous hyperplasias and in 50% of neoplastic lesions. Erosions were seen in 6% of sebaceous hyperplasias and 50% of neoplastic lesions. Good interobserver agreement was found for white/yellowish clods (k = 0.75), yellow scales (k = 0.83), brown/grey dots (k = 0.80), erosions (k = 0.82) and red/brownish scales/crusts (k = 0.75). There was moderate agreement for fissures (k = 0.48) and vascular pattern (k = 0.51-0.53). CONCLUSIONS AND CLINICAL RELEVANCE: Dermoscopy represents a useful technique to assess sebaceous gland proliferations in dogs, as it is in humans.

Upregulated MYC expression and p53 mutations may contribute to the oncogenesis of canine Meibomian gland carcinomas.

Sebaceous carcinomas of the human ocular adnexa commonly exhibit pagetoid spread, mutations in tumor-suppressor genes, and protooncogene copy number gain. Sebaceous carcinomas are rarely reported in other species, and while the Meibomian gland (MG) represents the most common ocular adnexal structure of the canine eyelid to develop neoplasia, most are clinically and histologically benign. The objective of this study was to compare molecular features of canine MG carcinomas and adenomas. Two retrospectively identified MG carcinomas were subject to immunohistochemistry and qPCR. When compared with normal glands, MYC was upregulated in benign and malignant MG neoplasms. Aberrant p53 expression was restricted to the nuclei of intraepithelial neoplastic cells in MG carcinomas. Adipophilin expression was diminished in MG neoplasms compared with the normal MG. Our findings, if confirmed in a larger cohort of cases, could suggest that MG oncogenesis in a dog may exhibit similar molecular features as their human counterparts.

Evaluation of electrochemotherapy in the management of apocrine gland anal sac adenocarcinomas in dogs: A retrospective study.

Background: Electrochemotherapy (ECT) combines the administration of anticancer drugs with the delivery of electric pulses, thus increasing the drug uptake through the cell membranes, resulting in increased efficacy. Aim: The aim of our study was to describe the tolerability and efficacy of ECT alone or in association with other treatment modalities for the management of apocrine gland anal sac adenocarcinoma (AGASAC). Methods: Medical records of dogs with a diagnosis of AGASAC that were treated with ECT alone or in combination with surgery/chemotherapy were retrospectively evaluated. Each dog received 20 mg/m2 of bleomycin intravenously. Based on the clinician's decision, the primary tumor or tumor bed was also infiltrated with cisplatin at the dose of 0.5 mg/cm2. Trains of permeabilizing biphasic electric pulses were then applied under general anesthesia. Results: Ten dogs were enrolled in the study. Of those 10 dogs, only one received ECT for treatment of microscopic local disease, while in six cases ECT was the only treatment modality. In three dogs, ECT was followed by systemic medical treatment. Six dogs (60%) had a partial response (PR), three dogs (30%) had stable disease, and one dog treated for microscopic disease did not show any sign of local relapse for 305 days after treatment, being still alive and in complete remission at the time of writing this article. The median time to progression was 303 days and the median survival time was 365 days. The treatment was well tolerated and local side effects were minimal. No systemic effects were documented. Conclusion: This preliminary study suggests that ECT may be beneficial for dogs with AGASAC and could be a useful addition to the current therapeutic options in consideration of its low cost, limited toxicity, and ease of administration.

Histopathological study of canine sebaceous tumors and their association with PCNA expression by immunohistochemistry / Estudo histopatológico de tumores sebáceos caninos e sua associação com a expressão de PCNA por imuno-histoquímica

Sebaceous tumors are common in dogs. These tumors include both benign and malignant lesions. Immunohistochemical evaluation of these tumors can aggregate information regarding the origin and degree of malignancy of the lesions. Focusing on this matter, sixty-one samples including normal skin and sebaceous tumors were selected from dogs of various breeds and ages, with no predilection for sex, from the archive of Veterinary Pathology Service of Federal Fluminense University, Niterói/RJ, Brazil. The samples underwent to histological processing, routine staining and immunohistochemistry with anti-PCNA (proliferating cell nuclear antigen). Descriptive statistical analysis was performed, the Wilcoxon-Mann-Whitney test was used to compare the distribution of anti-PCNA labelling in different groups of variables. In case there were more than two groups, the Analysis of Variance (ANOVA) test was performed. The mean age of the affected animals was 10.56 years. The most affected breeds were Caniches and Cocker Spaniels, as well as mixed breed animals. There was immunostaining of PCNA in both benign and malignant tumors, as well as in hyperplasic lesions with varying intensity. Most of the tumors were neoplasms which represented 67.27% of the total sample; within these, 75.00% were benign. The most frequent neoplasm was sebaceous adenoma (37.74%). Results indicated no statistical difference in the distribution of anti-PCNA labelling between the groups of sex, age, reproductive status, localization, size of tumor, and histopathological diagnosis. Although there are not many studies analyzing anti-PCNA labelling in sebaceous tumors, several of them pointed out to the predictive value in other neoplasms. With this matter in mind, we intended to evaluate the expression of anti-PCNA in canine sebaceous tumor and a possible association with the malignancy of the lesions.

Tumores sebáceos são comuns em cães. Tais tumores incluem lesões benignas e malignas. A avaliação imunohistoquímica desses tumores pode agregar informações sobre a origem e o grau de malignidade das lesões. Para este fim, sessenta e uma amostras, incluindo pele normal e tumores sebáceos foram selecionadas de cães de várias raças e idades, sem predileção por sexo, do arquivo do Serviço de Patologia Veterinária da Universidade Federal Fluminense, Niterói/RJ, Brasil. As amostras passaram por processamento histológico, coloração de rotina e imuno-histoquímica com anti-PCNA (proliferating cell nuclear antigen). Foram realizadas análises estatísticas descritivas além dos testes de Wilcoxon-Mann-Whitney para comparar a distribuição da marcação de anti-PCNA entre grupos de variáveis. Para variáveis com mais de dois grupos, aplicou-se a Análise de Variância (ANOVA). A idade média dos animais afetados foi de 10.56 anos. As raças mais afetadas foram Caniches e Cocker Spaniel, e ainda animais sem raça definida. Houve imunomarcação de PCNA em tumores benignos, malignos, e ainda em lesões hiperplásicas com intensidade variada. A maioria dos tumores eram neoplásicos representando 67.92% do total; destes, 75.00% eram benignos. O adenoma sebáceo foi a neoplasia mais frequente (37.74%). Não foram encontradas diferenças significativas nas distribuições de anti-PCNA entre os grupos das variáveis sexo, idade, status reprodutivo, localização e tamanho do tumor e diagnóstico histopatológico. Embora não haja estudos com anti-PCNA em tumores sebáceos caninos, numerosas publicações apontam seu valor preditivo em outras neoplasias. Com isso, a finalidade deste estudo foi avaliar a expressão de anti-PCNA em tumores sebáceos caninos e sua possível associação com a malignidade das lesões.

Modified Tail Amputation Technique in a Blue and Gold Macaw (Ara ararauna) With Uropygial Gland Adenocarcinoma.

A 33-year-old male blue and gold macaw (Ara ararauna) presented with a 5-month history of an ulcerated lesion and feather loss at the tail base. Two 4-mm biopsies obtained by the primary care veterinarian were consistent with uropygial gland adenocarcinoma. The bird was examined at the Veterinary Medical Teaching Hospital, University of California, and on physical evaluation, the dorsal and ventral surface of the tail base were devoid of feathers, ulcerated and crusted without an identifiable uropygial gland. Complete blood count, plasma biochemistry panel, whole-body radiographs, and an echocardiogram were performed before surgery. The bird was anesthetized, and a complete amputation of the tail was performed. The skin was incised with a radiofrequency electrosurgical system approximately 2 mm circumferentially cranial to the diseased tissue. The musculature was transected to the level of the vertebral column, disarticulating between the second and third caudal vertebrae and transecting the spinal cord with a no. 15 blade. Lateral vertebral processes of the second vertebra were removed with a rongeur. Coccygeus lateralis muscles and tensor fasciae latae muscles and skin were closed laterolaterally with 2 layers and 3-0 polydioxanone suture. The bird recovered uneventfully and was discharged after 6 days of hospitalization. The histopathological diagnosis was adenocarcinoma with squamous differentiation, marked scirrhous response, and superficial epithelial ulceration. It was determined that narrow margins of unaffected tissue were achieved from the pathological examination of submitted material. The bird was evaluated 24 days after surgery and again 3.5 months after surgery, without evidence of complications or recurrence. Approximately 10 days after the last reexamination, the bird was euthanatized after being found minimally responsive at home. A postmortem examination was not performed.

Retrospective study of canine cutaneous tumors in Japan, 2008-2017.

Cutaneous tumors are commonly found in dogs. To date, few studies have investigated the epidemiology of canine cutaneous tumors in Asian countries. The present study aims to report the prevalence of canine cutaneous tumors in Japan, and assess the association of breed, age, sex, and anatomical locations with the development of common tumor types. A total of 1,435 cases of cutaneous tumors were examined, of which 813 (56.66%) cases were malignant, and 622 (43.34%) were benign. Soft tissue sarcomas (18.40%), mast cell tumor (16.24%), lipoma (9.69%), hair follicle tumors (9.34%), and benign sebaceous tumors (8.50%) outnumbered the other tumor types. Tumors were commonly found on the head (13.87%), hindlimb (10.52%), forelimb (8.01%), chest (5.78%), and neck (5.57%). The risk of developing cutaneous tumors increased significantly in dogs aged 11-year and above (P<0.001). Mixed-breed dogs (14.63%), Miniature Dachshund (9.90%), and Labrador Retriever (8.01%) were the three most presented breeds; while Boxer, Bernese Mountain Dog, and Golden Retriever had an increased risk of cutaneous tumor development in comparison to mixed-breed dogs (P<0.05). Epidemiological information from the present study will serve as a useful reference for regional veterinarians to establish a preliminary diagnosis of canine cutaneous tumors.

Caracterização anatomopatológica e imuno-histoquímica dos tumores das glândulas cutâneas em cães / Anatomopathological and immunohistochemical characterization of skin gland tumors in dogs

O presente estudo objetivou caracterizar os aspectos anatomopatológicos e imuno-histoquímicos dos tumores das glândulas cutâneas em cães. A caracterização morfológica seguiu a classificação atualizada da Organização Mundial de Saúde. Para a caracterização imuno-histoquímica, utilizaram-se anticorpos monoclonais primários anti-citoqueratina 14 (CK14), vimentina, p63, calponina, EGFR e Ki-67. Dos animais examinados, 66,67% (18/27) eram machos e 33,33% (9/27) fêmeas, 21 tinham raça definida e seis eram sem raça definida (SRD), com idade variando entre sete e 15 anos. Dos tumores caracterizados, 40,74% eram hepatoides (11/27), 29,63% sebáceos (8/27), 25,92% apócrinos (7/27) e 3,70% meibômio (1/27). Os tumores malignos representaram 55,56%, e os benignos 44,44%. Com esses resultados, foi possível demonstrar que os tumores das glândulas cutâneas em cães são frequentes, sem predileção por raça, sexo e com idade superior ou igual a sete anos. Os anticorpos CK 14, p63, vimentina e EGFR foram imunoexpressos nas células basais, células de diferenciação sebácea dos tumores hepatoides e de meibômio e células mioepiteliais. Entretanto, a vimentina e o EGFR não demonstraram imunomarcação para os tumores sebáceos. A calponina foi um bom marcador para as células mioepiteliais. O índice de Ki-67 foi mais acentuado nos tumores malignos em relação aos benignos. No entanto, estudos futuros utilizando maior número de casos se fazem necessários.(AU)

The present study aimed to characterize the anatomopathological and immunohistochemical aspects of cutaneous glandular tumors in dogs. Tumours were diagnosed according to the WHO criteria for canine skin neoplasms. For the immunohistochemical characterization, the primary monoclonal antibodies anti-cytokeratin 14 (CK14), vimentin, p63, calponin, EGFR and Ki-67 were used. Males were 66.67% (18/27) and females 33.33% (9/27), 21 had a defined race and 6 were mixed breed, with ages varying from 7 to 15 years. The tumors characterized were 40.74% hepatoid (11/27), 29.63% sebaceous (8/27), 25.92% apocrine (7/27) and 3.70% Meibômio (1/27). Malignant tumors accounted for 55.56% and benign tumors 44.44%. With these results it was possible to demonstrate that tumors of cutaneous glands in dogs are frequent, with no predilection for race, sex and with an age ≥ seven years. The CK 14 antibodies, p63, vimentin, and EGFR were imunoexpressed in the basal cells of the sebaceous cell differentiation and Meibomian hepatoides tumors and myoepithelial to cells. However, vimentin and EGFR did not demonstrate immunostaining for sebaceous tumors. Calponin was a good marker for myoepithelial cells. The Ki-67 index was more pronounced in malignant tumors compared to benign tumors. However, more studies are needed mainly using a higher number of tumors.(AU)

Intra-oral Sebaceous Gland Tumours in Two Dogs.

A 12-year-old female miniature schnauzer and a 12-year-old neutered female cocker spaniel each had a grey-yellow nodular lesion arising from the gingiva. Microscopical examination showed that both nodules were composed of varied proportions of sebocytes and basal-type reserve cells with few ducts lined by stratified squamous epithelium. Based on the histopathological findings, the cases were diagnosed as sebaceous adenoma and sebaceous epithelioma, respectively. In man, the occurrence of sebaceous neoplasms in the oral cavity has been reported to some extent, but these lesions are very rare in animals. To the best of our knowledge, this is the first report of intra-oral sebaceous neoplasms in dogs. Intra-oral sebaceous epithelioma has never been reported in animals.

Histopathological findings and proliferative activity of canine sebaceous gland tumours with a predominant reserve cell population.

Sebaceous gland tumours represent the third most common skin tumours in dogs, but diagnostic criteria for tumours with basal differentiation (i.e. sebaceous epithelioma) are poorly defined and there is lack of correlation with biological behaviour. The aim of this study was to identify the main histological criteria associated with malignancy in 30 canine sebaceous gland tumours with a predominant reserve cell population. For each case, tumour proliferative activity was assessed by determining mitotic index and the Ki67/MIB-1 index. Additional histological features included endophytic or exophytic growth, proportion of reserve/intermediate/mature cells, connection to the epidermis, nuclear characteristics, peripheral invasion, neoplastic emboli and necrosis. Mitotic and Ki67 indexes were variable, but correlated (R = 0.66; P < 0.001), and both were significantly higher in infiltrative tumours (P = 0.018 and P < 0.001, respectively). No significant difference in histological features was observed between tumours comprised of more or less than 90% reserve cells, nor among tumours showing proliferative activity in sebocytes. This study suggests that high proliferative activity and peripheral invasion should be considered the most significant parameters for the differentiation between benign and malignant sebaceous gland tumours. Furthermore, the incidence of circumanal gland and testicular tumours in these dogs was significantly higher compared with an age-matched control population, suggesting a potential androgen-related pathway for the tumourigenesis of canine sebaceous gland neoplasms.

Sebaceous gland carcinoma and mammary gland carcinoma in an African hedgehog (Ateletrix albiventris).

A sebaceous carcinoma was diagnosed, together with a mammary carcinoma, in an adult African hedgehog (Atelerix albiventris). The first neoplasm was located in the subcutaneous tissue of the neck and extended towards the axillary area of the chest. The second was located in the subcutaneous left caudal abdominal region. The purpose of this paper is to report the histopathologic and ultrastructural features of these neoplasms. Although there is little information about diseases affecting this species, it is known that neoplastic disorders are fairly common in African hedgehogs. The mammary carcinoma is considered to be the most common neoplasm in these animals; however, the presentation of sebaceous carcinoma is rare. In hedgehogs, the simultaneous presence of two neoplasms is common, which is why special attention should be paid to the presentation of other tumors during the early detection of a neoplastic process as this will greatly facilitate the optimal treatment and improve the long-term prognosis of affected animals.

Nuclear survivin expression as a potentially useful tool for the diagnosis of canine cutaneous sebaceous lesions.

BACKGROUND: Sebaceous glands are specialized cutaneous adnexal glands, which work under constant hormonal control to produce sebum. They can give rise to several proliferative lesions, such as hamartoma, hyperplasia and neoplasms (adenoma, epithelioma and carcinoma). Their nomenclature is currently confusing, both in veterinary and in human medicine, owing to the difficulty of differentiating between some of these lesions. METHODS: The present study used immunohistochemistry to determine the expression levels and patterns of survivin and Ki67 in five samples of normal canine skin and 44 cases of canine cutaneous lesions with sebaceous differentiation (10 hamartomas, nine hyperplasia, eight adenomas, eight epitheliomas and nine carcinomas). RESULTS: In normal glands, survivin, as well as Ki67, was expressed in scattered reserve cells. In hamartomas, survivin was more highly expressed than in normal skin, indicating a possible role of this molecule in the pathogenesis of these congenital lesions. In tumours, a moderate or high level of survivin and Ki67 expression (more than two and four and more than two positive cells, respectively) were significantly correlated with a malignant histotype, infiltrative growth and a moderate or high number of mitoses (more than two). CONCLUSIONS AND CLINICAL IMPORTANCE: The level of survivin expression increased with increasing malignancy, designating survivin as a new diagnostic marker in the assessment of malignancy of sebaceous tumours.

Sebaceous metaplasia in a canine mammary gland non-infiltrative carcinoma with myoepithelial component.

Sebaceous metaplasia in canine mammary tumors is a rare condition with only 1 case documented. The current study describes a case of sebaceous metaplasia in a mammary gland carcinoma of an 8-year-old intact, nulliparous female Poodle dog with a subcutaneous tumor located in the left fifth mammary gland. The lesion measured 0.7 cm × 0.5 cm × 0.6 cm in diameter, was firm, circumscribed, painless, non-haired, and non-ulcerated, and did not adhere to deep tissues. The cut surface was non-lobulated, non-encapsulated, whitish to gray, and opaque. Histological evaluation revealed 3 different populations of cells: the first was composed of columnar to cuboidal malignant epithelial cells arranged in intraductal papillary projections, the second of myoepithelial cells associated with a myxoid stroma, and the third presenting sebaceous metaplasia similar to those previously described in both human and veterinary medicine.

Expression of oestrogen and progesterone receptors in canine sebaceous gland tumours.

Sebaceous gland oestrogen alpha (ERalpha) and progesterone (PR) receptor expression was examined immunohistochemically in 26 and 32 dogs respectively with sebaceous gland hyperplasia/adenomas, epitheliomas and carcinomas, and in the glands of 10 healthy controls. The mean percentage of ERalpha positive nuclei in control sebaceous glands was 21.31% compared with 11.5% in hyperplasia/adenoma-type lesions, although these values were not statistically different. In sebaceous gland epitheliomas and carcinomas, positive basal cells represented 7.86% and 3.53% of neoplastic cells respectively and these mean percentages were significantly lower in epitheliomas (P < 0.024) and carcinomas (P < 0.015) than in controls. The mean percentage of PR-positive nuclei in control sebaceous glands was 23.96%, similar to the 22.07% found in hyperplasia/adenoma-type lesions. In sebaceous gland epitheliomas and carcinomas, positive cells were scarce and represented 13.5% and 4.06% of neoplastic cells respectively. Differences in the percentage of positive cells between normal and pathological glands reached statistical significance for carcinomas (P < 0.043). In the control group there was greater PR (P < 0.001) and ERalpha expression (P < 0.014) in sebaceous glands in female dogs. The PR and ERalpha immunoreactivity in each category of neoplastic lesions could not be analysed because sample size was too small but when all the sebaceous gland tumours were grouped and analysed, no sex difference was found. The results suggest that oestrogen and progesterone receptor expression is reduced in some canine sebaceous gland tumours. These changes may represent a contributing factor for tumour growth or simply be a consequence of tumour progression.

Immunohistochemical characterization of a sebaceous gland carcinoma in a gerbil (Meriones unguiculatus).

Sebaceous gland carcinoma is a common tumour in male gerbils but, to date, no information is available on its immunohistochemical properties. This report describes the histopathological and immunohistochemical features of such a tumour from a 4.5-year-old male gerbil. The tumour immunoreactivity profile was studied in respect of p53 protein, CEA, EMA, c-erbB-2, cytokeratin (CK) 14 and the CKs detected by AE1/AE3 antibodies (i.e. high molecular weight CKs 1, 2, 3, 4, 5, 6, 10, 14, 15 and 16, and low molecular weight CKs 7, 8 and 19). The differences observed in p53 and c-erbB-2 immunolabelling between carcinomatous and hyperplastic areas suggest that p53 mutations and amplification of c-erbB-2 may play a significant role in the oncogenesis of sebaceous gland carcinoma in the gerbil.

Cutaneous mass aspirate from a Golden Retriever: "glandular guile".

A 3-year-old, neutered, male Golden Retriever was presented for evaluation of a 10 X 9 X 5 mm, firm, red, raised, cutaneous mass located over the left cranial thorax and noted incidentally by the owner. On cytologic evaluation of a fine-needle aspirate of the mass, the interpretation was a malignant tumor with predominantly mesenchymal features. Differentials included liposarcoma, atypical amelanotic melanoma, anaplastic sarcoma, and anaplastic carcinoma. Following complete excision of the mass, a diagnosis of sebaceous adenocarcinoma was made based on histologic features, positive immunostaining for pancytokeratin, and negative staining for vimentin, Melan-A, and S-100. There was no evidence of metastasis on physical examination or thoracic radiographs, and the prognosis was good. The unique and previously unreported cytologic features of this small, sebaceous adenocarcinoma were the extreme pleomorphism, including marked anisocytosis, anisokaryosis, and multinuclearity, and the paucity of epithelial features.