Pilot study to evaluate isolation by size of circulating tumour cells in canine oral melanoma.

Liquid biopsy for circulating tumour cell (CTC) detection is generally unexplored in veterinary medicine. Dogs with highly aggressive and heterogeneous tumours, such as oral malignant melanoma (OMM), could benefit from studies involving size-based isolation methods for CTCs, as they do not depend on specific antibodies. This pilot study aimed to detect CTCs from canine OMM using Isolation by Size of Epithelial Tumor Cells (ISET), a microfiltration methodology, followed by immunocytochemistry (ICC) with Melan-A, PNL2, and S100 antibodies. Ten canine patients diagnosed by histopathology and confirmed as OMM by immunohistochemistry were enrolled, their prognostic data was assessed, and blood samples were collected for CTC analysis. Results have shown the detection of intact cells in 9/10 patients. ICC has shown 3/9 Melan-A-positive, 3/9 PNL2-positive, and 8/9 S100-positive patients, confirming the importance of opting for a multimarker assay. A significant number of negative-stained CTCs were found, suggesting their high heterogeneity in circulation. Microemboli stained with either PNL2 or S100 were found in a patient with a high isolated cell count and advanced clinical stage. Preliminary statistical analysis shows a significant difference in CTC count between patients with and without lymph node metastasis (p < .05), which may correlate with tumour metastatic potential. However, we recommend further studies with more extensive sampling to confirm this result. This pilot study is the first report of intact CTC detection in canine OMM and the first application of ISET in veterinary medicine, opening new possibilities for liquid biopsy studies in canine OMM and other tumours.

Review of the comparative pathological and immunohistochemical features of human and canine cutaneous melanocytic neoplasms.

Melanocytic neoplasms originate from melanocytes and melanoma, the malignant form, is a common canine neoplasm and the most aggressive human skin cancer. Despite many similarities between these neoplasms in both species, only a limited number of studies have approached these entities in a comparative manner. Therefore, this review compares benign and malignant melanocytic neoplasms in dogs and humans, exclusively those arising in the haired skin, with regard to their clinicopathological, immunohistochemical and molecular aspects. Shared features include spontaneous occurrence, macroscopic features and microscopic findings when comparing human skin melanoma in the advanced/invasive stage and canine cutaneous melanoma, immunohistochemical markers and several histopathological prognostic factors. Differences include the apparent absence of active mutations in the BRAF gene in canine cutaneous melanoma and less aggressive clinical behaviour in dogs than in humans. Further studies are required to elucidate the aetiology and genetic development pathways of canine cutaneous melanocytic neoplasms. Evaluation of the applicability of histopathological prognostic parameters commonly used in humans for dogs are also needed. The similarities between the species and the recent findings regarding genetic mutations in canine cutaneous melanomas suggest the potential utility of dogs as a natural model for human melanomas that are not related to ultraviolet radiation.

Lesions of the oral cavity of dogs: 720 cases / Lesões da cavidade oral de cães: 720 casos

Seven hundred twenty cases of oral cavity lesions in dogs were diagnosed from 2015 to 2020 in Distrito Federal, Brazil. Four hundred thirty-two (60%) lesions were neoplastic, and 288 (40%) were non-neoplastic. Of the neoplasms, 229 (53%) were considered malignant and 203 (47%) benign, affecting mainly males, of 43 different breeds, with an average age of 9.4 years, mainly the gum and lip. Melanoma was the most (96/432, 22.2%) commonly diagnosed neoplasm, followed by peripheral odontogenic fibroma (68/432, 15.7%), papilloma (63/432, 14.5%) and squamous cell carcinoma (SCC) (56/432, 12.9%). Non-neoplastic lesions also affected males predominantly, from 41 different breeds, with an average age of 8.9 years, mainly in the gums, lip, and tongue. These lesions were diagnosed as inflammatory (230/288, 79.8%), hyperplastic (47/288, 16.3%) and other lesions (11/288, 3.8%).

Foram estudados 720 casos de lesões na cavidade oral em cães diagnosticados entre 2015 e 2020, no Distrito Federal. Dessas alterações, 432 (60%) foram neoplásicas e 288 (40%) não neoplásicas. Dentre os neoplasmas, 229 (53%) foram consideradas malignos e 203 (47%) benignos, acometendo principalmente machos, de 43 raças diferentes, com idade média 9,4 anos, afetando principalmente gengiva e lábio. Melanoma foi o neoplasma mais comumente diagnosticado (96/432; 22,2%), seguido do fibroma odontogênico periférico (68/432; 15,7%), papiloma (63/432; 14,5%) e carcinoma de células escamosas (56/432; 12,9%). As lesões não neoplásicas também acometeram predominantemente machos, de 41 raças diferentes, com idade média 8,9 anos, afetando principalmente gengiva, lábio e língua. Essas lesões foram diagnosticadas como inflamatórias (230/288; 79,8%), hiperplásicas (47/288; 16,3%) e como outras alterações (11/288; 3,8%).

Retrospective study of cutaneous neoplasms in horses treated at the Livestock Development Center of the Federal University of Bahia / Estudo retrospectivo das neoplasias cutâneas em equinos atendidos no Centro de Desenvolvimento da Pecuária da Universidade Federal da Bahia

The aim of this study was to determine the prevalence of cutaneous neoplasms in horses treated at the Center for the Development of Livestock at the Federal University of Bahia, as well as to correlate it with the coat color, breed, and age of the animal. For that, the attendance records for the last ten years were reviewed. When evaluating the files, 13 cases of cutaneous tumor in horses confirmed by histopathology and cytology were observed. The most prevalent skin tumors were sarcoid (38.5%), melanoma (23%), and fibrosarcoma (15.4%). Regarding the equine coat color, gray and sorrel horses were the most frequent with 30.7% and 23.1% of cases, respectively. As for the equine breed, the mangalarga marchador was the most prevalent (38.4%). Regarding age, 38.46% of the horses were up to 5 years old, 30.77% of the animals were between 4 and 10 years old, and 30.76% were between 11 and 16 years old. In the end, it can be concluded that sarcoid and melanoma were the most prevalent neoplasms.

Objetivou-se com este trabalho determinar a prevalência de neoplasias cutâneas em equinos atendidos no Centro de Desenvolvimento da Pecuária da Universidade Federal da Bahia, bem como correlaciona-la com a pelagem, raça e idade do animal. Para tanto revisou-se as fichas de atendimento dos últimos dez anos. Ao avaliar as fichas, observou-se 13 casos de tumor cutâneo em equinos confirmado por histopatologia ou citologia. Os tumores cutâneos mais prevalentes foram sarcoide (38,5%), melanoma (23%) e fibrossarcoma (15,4%). Com relação a pelagem, equinos tordilhos e alazões foram os mais frequentes com 30,7% e 23,1% dos casos, respectivamente. Quanto as raças, a mangalarga marchador foi a mais prevalente (38,4%). Em relação a idade, 38,46% dos equinos possuíam até 5 anos de idade, 30,77% dos animais apresentavam idade entre 4 e 10 anos e, 30,76% apresentavam idade entre 11 e 16 anos. Ao fim, pode-se concluir que o sarcoide e o melanoma foram as neoplasias mais prevalentes.

Metastatic Digital Chondrogenic Melanocytic Tumour in a Dog.

A 9-year-old intact male Brazilian Mastiff dog with a 1-year history of progressive severe swelling in all four limbs and significant locomotory difficulty was euthanized due to unresponsiveness to medical management. Macroscopically, the distal phalanx of the 5th digit of the left hindlimb was replaced by a cutaneous, non-ulcerated, 3.0 cm diameter, multilobulated, black, firm nodule. The cortical bones of the appendicular skeleton were thickened and partially effaced by infiltrative coalescing nodules (0.1-1.0 cm diameter). The lungs, heart, pleura, mesentery, adrenal glands and kidneys were infiltrated by similar nodules (0.5-3.5 cm diameter). Histological evaluation of the masses revealed a non-encapsulated malignant neoplasm composed of spindloid to polygonal cells that contained variable amounts of intracytoplasmic melanin and were arranged in haphazardly interlacing streams and bundles supported by scant fibrovascular stroma with myxoid and chondroid matrix formation. Neoplastic cells had intense cytoplasmic labeling for S100 and 10% had moderate cytoplasmic immunoreactivity for Melan-A. To the authors' knowledge, this is the first description of a canine metastatic digital chondrogenic melanocytic tumour with strongly suggestive chondroid differentiation of neoplastic melanocytes.

Canine and feline uveal melanocytic tumours: Histologic and immunohistochemical characteristics of 32 cases.

OBJECTIVE: Gross, histopathological, and immunohistochemical characteristics of uveal melanocytic neoplasms in dogs and cats were investigated. SAMPLES: Thirty-two enucleated globes with uveal melanocytic neoplasms, 27 from dogs and 5 from cats, were examined. PROCEDURES: Morphological characteristics of uveal melanocytic neoplasms in dogs and cats were evaluated with anti-PNL2, anti-Melan-A, anti-Ki-67, anti-caspase-3, and anti-BAP1 immunomarkers. Statistical analysis was performed to compare canine melanocytomas and melanomas. RESULTS: The 32 uveal neoplasms were classified as melanocytomas (19/27 in dogs) or melanomas (8/27 in dogs, 5/5 in cats). Most tumours (84%) were located in the anterior uvea. Neoplastic cells were classified as epithelioid, spindle-shaped, mixed, or special type (balloon and signet ring cells). The percentage of cells with melanin, melanin concentration within cells, anisocytosis and anisokaryosis, mitotic count, lymphocytic inflammation, necrosis, vascular invasion, and glaucoma were also characterized. Anisocytosis, percentage of neoplastic cells with melanin, mitotic count, and indices (proliferation and apoptotic) varied significantly between canine uveal melanomas and melanocytomas; in general, melanomas had greater cell variability, were less pigmented, and had a higher mitotic count. The melanocytic origin of the neoplasms was confirmed by positive anti-PNL2 immunolabelling (29/32) and positive anti-Melan-A immunolabelling (3/32). In canine uveal melanomas, anisocytosis and anisokaryosis correlated with less pigmentation and minimal pigmentation correlated with a high percentage of immunolabelling for caspase-3. CONCLUSIONS: Uveal melanocytomas were more common in dogs, and uveal melanomas were more frequent in cats. Anisocytosis, percentage of neoplastic cells with melanin, and mitotic count are important histologic characteristics of malignancy to evaluate in uveal melanocytic neoplasms. The proliferation and apoptotic indices are relevant when comparing malignant tumours with benign tumours.

Primary perianal malignant melanoma in a dog - combination therapy

Background: Melanocytic neoplasm can arise from melanocytes in any location of the body. Malignant melanoma (MM)has a poor prognosis in dogs and presence of lymphvascular invasion, distant metastasis, or mitotic activity present prognostic value. Primary melanoma affecting the gastrointestinal tract has been rarely reported in veterinary literature, thusthe prognosis affecting gastrointestinal tract is unknown. Electrochemotherapy (ECT) is an effective local treatment whichcombines chemotherapeutic drugs mainly bleomycin or cisplatin followed by the delivery of permeabilizing electricalpulses However, other hydrophilic drugs seem to present an increase cytotoxic effect such as carboplatin.Case: A 9-year-old mixed-breed neutered dog was referred to a private clinic with a mass in the perianal region diagnosedas perianal melanoma. No metastasis was observed on abdominal ultrasound nor chest x-ray (3 views). Clinical signs notedwere tenesmus, hemorrhagic discharge, weight loss and hyporexia. Considering the tumor volume (16.0 x 10.0 cm), a neoadjuvant ECT session was proposed. The authors opted for carboplatin (300 mg/m2, intravenously), administered over 20min and cisplatin intratumorally (1 mg/cm3, equivalent to 1 mL/1cm3 total volume 20 mL) administered in the upper partsof the mass that could be reached while avoiding drug leakage. After administration, sequences of eight biphasic pulses,(100 microseconds), with a voltage ranging from 650-1,000V/cm (pulse generator Onkodisruptor®) using a hexagonal/single pair and plate electrode were delivered. At day 30th, a partial response was observed accordingly to RECIST system,with tumor size of 5.0 x 5.0 cm (65.4 cm3). A second ECT session was performed with the same previous protocol, butwith a decreased dosage of carboplatin (240 mg/m2 consistent with 20% reduction) due to adverse effects in the first session, resulting in stable disease at day 60th (30 days after second ECT). Then...(AU)

Primary perianal malignant melanoma in a dog - combination therapy

Background: Melanocytic neoplasm can arise from melanocytes in any location of the body. Malignant melanoma (MM)has a poor prognosis in dogs and presence of lymphvascular invasion, distant metastasis, or mitotic activity present prognostic value. Primary melanoma affecting the gastrointestinal tract has been rarely reported in veterinary literature, thusthe prognosis affecting gastrointestinal tract is unknown. Electrochemotherapy (ECT) is an effective local treatment whichcombines chemotherapeutic drugs mainly bleomycin or cisplatin followed by the delivery of permeabilizing electricalpulses However, other hydrophilic drugs seem to present an increase cytotoxic effect such as carboplatin.Case: A 9-year-old mixed-breed neutered dog was referred to a private clinic with a mass in the perianal region diagnosedas perianal melanoma. No metastasis was observed on abdominal ultrasound nor chest x-ray (3 views). Clinical signs notedwere tenesmus, hemorrhagic discharge, weight loss and hyporexia. Considering the tumor volume (16.0 x 10.0 cm), a neoadjuvant ECT session was proposed. The authors opted for carboplatin (300 mg/m2, intravenously), administered over 20min and cisplatin intratumorally (1 mg/cm3, equivalent to 1 mL/1cm3 total volume 20 mL) administered in the upper partsof the mass that could be reached while avoiding drug leakage. After administration, sequences of eight biphasic pulses,(100 microseconds), with a voltage ranging from 650-1,000V/cm (pulse generator Onkodisruptor®) using a hexagonal/single pair and plate electrode were delivered. At day 30th, a partial response was observed accordingly to RECIST system,with tumor size of 5.0 x 5.0 cm (65.4 cm3). A second ECT session was performed with the same previous protocol, butwith a decreased dosage of carboplatin (240 mg/m2 consistent with 20% reduction) due to adverse effects in the first session, resulting in stable disease at day 60th (30 days after second ECT). Then...

Therapeutic potential of the cytosine deaminase::uracil phosphoribosyl transferase/5-fluorocytosine suicide system for canine melanoma.

We tested the efficacy of a yeast cytosine deaminase::uracil phosphoribosyl transferase/5-fluorocytosine (CDU/5-FC) non-viral suicide system on eight established canine melanoma cell lines. Albeit with different degree of sensitivity 5 days after lipofection, this system was significantly efficient killing melanoma cells, being four cell lines highly, two fairly and two not very sensitive to CDU/5-FC (their respective IC50 ranging from 0.20 to 800 µM 5-FC). Considering the relatively low lipofection efficiencies, a very strong bystander effect was verified in the eight cell lines: depending on the cell line, this effect accounted for most of the induced cell death (from 70% to 95%). In our assay conditions, we did not find useful interactions either with the herpes simplex thymidine kinase/ganciclovir suicide system (in sequential or simultaneous modality) or with cisplatin and bleomycin chemotherapeutic drugs. Furthermore, only two cell lines displayed limited useful interactions of the CDU/5-FC either with interferon-ß gene transfer or the proteasome inhibitor bortezomib respectively. These results would preclude a wide use of these combinations. However, the fact that all the tested cells were significantly sensitive to the CDU/5-FC system encourages further research as a gene therapy tool for local control of canine melanoma.

Melanomas em cães no Sertão do Nordeste do Brasil - epidemiologia, fatores de risco e achados clinicopatológicos / Melanoma in dogs in the backlands of Northeastern Brazil - epidemiology, risk factors and clinicopathological findings

Background: Melanoma is a malignant neoplasm that arises from melanocytes and malanoblasts. It is also more frequently reported in dogs than in other species. They may arise from melanocytes in the skin, on the surfaces of the mucous membranes, and eyes. The aim of this study was to describe the epidemiological aspects, risk factors and clinicopathological findings of melanoma in dogs in the backlands, northeastern Brazil. Materials, Methods & Results: A retrospective study was carried out in all biopsy samples and necropsy examinations of dogs, from January 2003 to December 2021, at the Animal Pathology Laboratory of the Federal University of Campina Grande, Patos, Paraiba, northeastern Brazil. Epidemiological data, clinical signs, and gross lesions were reviewed from the diagnostic laboratory reports. Samples of the skin, lymph nodes, central nervous system and organs of the thoracic and abdominal cavities were fixed in 10% buffered formalin, processed routinely for histopathology, embedded in paraffin wax, cut into 4 µm sections, and stained with hematoxylin and eosin (HE). Histological sections were also submitted to immunohistochemistry with the primary antibody anti-Melan A. Of the 4717 records found, 1158 (24.5%) were diagnosed with neoplasms, of which 48 (4.14%) cases were of melanoma. Of this total, 28 (58.3%) dogs were elderly, 19 (39.6%) were adults, and 1 (2.1%) was young. Mixed breed animals were the most affected (42.6%), followed by the pinscher breed (19.1%). According to the anatomical region, the most affected site was the skin (38/53=71.7%), followed by the oral cavity (12/53=22.65%) and the eyes (3/53=5.7%). Grossly, the skin lesions were characterized by exophytic and usually blackened, sometimes irregular and firm, nodules. At cut, they had a smooth, compact and blackened surface. Lesions in the oral cavity were characterized by blackened, irregular and infiltrating nodules or masses. The ocular lesions were always unilateral and were characterized by an enlarged and diffusely blackened eyeball, with areas of ulceration and subversion of tissue architecture. In 5 animals there was more than one anatomical site affected, totaling 53 lesions. In 9 (17%) cases, metastases were identified, 8 in regional lymph nodes and 1 in the lung. Histopathology showed a densely non-encapsulated, poorly delimited, expansive and infiltrative neoplasm, composed of neoplastic cells arranged in islands or nests and supported by fibrovascular stroma, containing a variable amount of brownish pigment (melanin). Immunohistochemistry showed strong immunostaining of the neoplastic cells in brown by the anti-Melan A antibody. Discussion: The diagnosis of melanoma was established based on epidemiological, clinical, anatomopathological, and immunohistochemical findings. Gender is not a predisposing factor, and although there was no statistically significant relationship, males were more affected. Senescence is a conditioning risk factor. Elderly animals were more affected (P < 0.0001) than adult ones, with OR = 4.38; and young ones (P = 0.0051), with OR = 12.65. Some breeds, especially those with marked skin pigmentation, were more affected, however the most affected ones in this survey were pinscher and poodle. Cutaneous melanoma accounted for almost 72% of cases, contesting recent studies where oral cavity melanoma was more frequent. Therefore, it is believed that the climatic conditions of the backlands sub-region, in northeastern Brazil, associated with the individual characteristics of the dogs, are involved in the development of these neoplasms, since the climate is predominantly dry, with high temperatures throughout the year, with maximums that can reach 40ºC, favoring the exposure to high incidence of ultraviolet radiation.

Treatment of canine oral melanoma with adjuvant chemotherapy and immunotherapy

Background: Melanoma is the most frequent cancer in the canine oral cavity. It shows an aggressive behavior, characterized by rapid and invasive growth and high metastatic potential. Metastasis is seen in more than 80% of dogs at time ofdeath. Adjuvant therapy should be recommended because of potential recurrence and metastasis. Oral melanoma has a poorprognosis even when adjuvant treatments are used. There are some treatment options, but the high death rate due to thedisease is still a challenge. The aim of this study was to assess the overall survival of dogs diagnosed with oral melanomaand treated with adjuvant chemotherapy and immunotherapy.Materials, Methods & Results: A retrospective analysis was carried out in 20 dogs with oral melanocytic or amelanocyticmelanomas. Cases were staged according to a modified World Health Organization clinical staging system for canine oralmalignant melanoma. Tumor size (T1: < 2 cm; T2: 2 - 4 cm; T3: > 4 cm), regional metastasis (N0: no metastasis; N1:metastasis) and presence of distant metastasis (M0: no metastasis; M1: metastasis) are evaluated. Then, cases were dividedinto 4 stages: I (T1 N0 M0), II (T2 N0 M0), III (T3 N0-1 M0, Tx N1 M0) and IV (Tx Nx M1). Diagnoses were confirmedwith histopathological exam and immunohistochemistry (IHC) when necessary. In poorly differentiated neoplasms, IHC wasperformed at the request of the submitting veterinarian using specific markers PNL-2 and Melan-A. Animals were dividedinto 2 groups: dogs submitted to surgery alone were included in group 1 (G1); dogs submitted...(AU)

Intratumoral T-Lymphocyte Subsets in Canine Oral Melanoma and Their Association With Clinical and Histopathological Parameters.

Canine oral melanoma is a common, aggressive tumor with limited treatment options. Tumor-infiltrating lymphocytes (TILs) are important in antitumor immunity. This study used histopathology and immunophenotyping by flow cytometry to evaluate the presence and distribution of TILs in canine oral melanoma, including the frequency of CD8+ T cells, CD4+ T cells, and regulatory T cells. Fifty samples of oral melanoma from 45 dogs that did not receive treatment prior to surgery were included in the study. The distribution of TILs in the tissue (brisk, nonbrisk, and absent) was evaluated in 48 samples. Twenty-eight (58%) samples had a brisk distribution pattern, 10 (21%) samples had a nonbrisk pattern, and 10 (21%) samples had an absent TIL pattern. Comparing the histological evaluation and the immunophenotyping data, it was observed that samples with a brisk TIL pattern had a higher frequency of CD8+ T lymphocytes (P = .05) and a lower frequency of CD4+/CD25+/FoxP3+ Tregs (P = .03), compared to the samples with nonbrisk and absent infiltrate patterns. Patients with a higher survival rate had higher TIL scores (P = .002), a brisk or nonbrisk TIL pattern (P = .001), and an increased frequency of CD8+ T lymphocytes infiltrating the tumor (P = .003). Our analysis suggests that the evaluation of TILs in canine oral melanoma is relevant to predict tumor aggressiveness and patient prognosis.

Expression of the Wilms' tumour gene and its association with PPARß/δ in healthy skin and melanoma of horses.

The Wilms' tumour gene (WT1) has previously been described as an oncogene in several neoplasms of humans, including melanoma, and its expression increases cancer cell proliferation. Recent reports associate the expression of the PPARß/δ gene (peroxisome proliferator-activated receptor beta/delta) with the downregulation of WT1 in human melanoma and murine melanoma cell lines. The aim of this work was to analyse the expression of WT1 and its association with PPARß/δ in samples of healthy and melanoma-affected skin of horses by immunohistochemistry. WT1 protein expression was detected in healthy skin, mainly in the epidermis, hair follicle, sebaceous gland and sweat gland, while no expression was observed in equine melanoma tissues. Moreover, it was observed that PPARß/δ has a basal expression in healthy skin and that it is overexpressed in melanoma. These results were confirmed by a densitometric analysis, where a significant increase of the WT1-positive area was observed in healthy skin (128.66 ± 19.84 pixels 106) compared with that observed in melanoma (1.94 ± 0.04 pixels 106). On the other hand, a positive area with an expression of PPARß/δ in healthy skin (214.94 ± 11.85 pixels 106) was significantly decreased compared to melanoma (624.86 ± 181.93 pixels 106). These data suggest that there could be a regulation between WT1 and PPARß/δ in this disease in horses.

Prognostic Value of Intratumoral Collagen Quantification in Canine Oral Melanomas.

The majority of the melanocytic neoplasms are considered malignant and highly metastatic. However, a subset of the melanocytic tumors has a more favorable prognosis and the identification of precise prognostic markers for this neoplasm may be useful to guide treatment. The collagen architecture and density have been shown to correlate with tumor progression in human breast cancer and canine mast cell tumors. The purpose of the present study was to investigate the prognostic value of the intratumoral collagen index (ICI) as an indicator of postsurgical survival and its relation with other prognostic markers for canine oral melanomas (OMs). Twenty-two cases were tested for intratumoral collagen density using Masson's trichrome stain and morphometry. No differences were found between dogs regarding survival. The ICI was not correlated with proliferative activity or nuclear atypia. The results presented herein indicate that the quantity of intratumoral collagen in canine OMs is not an efficient indicator of postsurgical survival. Complementary studies about the expression and activity of enzymes that are capable of degrading extracellular matrix (ECM) components are necessary.

Treatment of canine oral melanoma with adjuvant chemotherapy and immunotherapy

Background: Melanoma is the most frequent cancer in the canine oral cavity. It shows an aggressive behavior, characterized by rapid and invasive growth and high metastatic potential. Metastasis is seen in more than 80% of dogs at time ofdeath. Adjuvant therapy should be recommended because of potential recurrence and metastasis. Oral melanoma has a poorprognosis even when adjuvant treatments are used. There are some treatment options, but the high death rate due to thedisease is still a challenge. The aim of this study was to assess the overall survival of dogs diagnosed with oral melanomaand treated with adjuvant chemotherapy and immunotherapy.Materials, Methods & Results: A retrospective analysis was carried out in 20 dogs with oral melanocytic or amelanocyticmelanomas. Cases were staged according to a modified World Health Organization clinical staging system for canine oralmalignant melanoma. Tumor size (T1: 4 cm), regional metastasis (N0: no metastasis; N1:metastasis) and presence of distant metastasis (M0: no metastasis; M1: metastasis) are evaluated. Then, cases were dividedinto 4 stages: I (T1 N0 M0), II (T2 N0 M0), III (T3 N0-1 M0, Tx N1 M0) and IV (Tx Nx M1). Diagnoses were confirmedwith histopathological exam and immunohistochemistry (IHC) when necessary. In poorly differentiated neoplasms, IHC wasperformed at the request of the submitting veterinarian using specific markers PNL-2 and Melan-A. Animals were dividedinto 2 groups: dogs submitted to surgery alone were included in group 1 (G1); dogs submitted...

Hemangiossarcoma associado a quimiodectoma em cadela Pit Bull idosa / Hemangiosarcoma associated with chemodectoma in an old Pit Bull bitch

Background: The prevalence of neoplasms in domestic animals has been augmenting over the years. Hemangiosarcoma, which most frequently affects large breed dogs, is a neoplasm with high metastatic power and corresponds to 5% of malignant neoplasms. Chemodectoma, a neoplasm that can have malignant or benign behavior, is uncommon, corresponding to less than 8% of all cardiac tumors, and originates from cardiac chemoreceptor cells and involves mainly the aortic and carotid bodies. The aim of this study is to describe the case of an elderly Pit Bull dog with hepatic hemangiosarcoma and chemodectoma associated with four other different tumors: hemangioma, papilloma, mastocitoma and melanoma. Case: A 14-year-old female Pit Bull, castrated, was presented to Veterinary Clinic of the Federal University of Santa Catarina (UFSC), Curitibanos Campus, Brazil. The owner referred apathy, hyporexia, and increased abdominal volume for two weeks. Physical examination showed emaciation and abdominal effusion. Abdominocentesis was performed, three liters of serosanguineous fluid was drained and a sample was sent for analysis. Complementary tests were requested and showed mild hypoalbuminemia, normocytic normochromic anemia, and lymphopenia. The ultrasound examination revealed thickening of vessels and hepatomegaly, in addition to the presence of an oval structure containing hyperechogenic cavitations. Diagnostic exploratory laparotomy was indicated, but the owner refused. Drug therapy was prescribed in a palliative manner and, during the clinical follow-up period, two abdominocentesis procedures and one thoracentesis procedure were performed, both resulting in simple transudate. Finally, the patient developed severe apathy, edema in all limbs, and died at home. Necroscopic examination was done and revealed hemoperitoneum and hemothorax...(AU)

Canine cutaneous neoplasms in the metropolitan region of Goiânia, Goiás state, Brazil / Neoplasias cutâneas caninas na região metropolitana de Goiânia, Goiás, Brasil

The present study aimed to describe the occurrence and epidemiological features of skin neoplasms diagnosed in dogs in the metropolitan region of Goiânia, Goiás state, Brazil. Diagnoses from dog biopsies from 2011 to 2016 provided by a private veterinary pathology laboratory were analyzed. The main diagnoses were mast cell tumor, hemangiosarcoma, squamous cell carcinoma, malignant melanoma, and hemangioma. Highest frequency of neoplasms was found in female dogs, dogs aged > 8 years, and purebred dogs, particularly the American Pit Bull Terriers and the Poodles. Most common sites affected by the neoplasms were the limb and the head. Using multiple correspondence analysis, groups of neoplasms were found to be associated with different epidemiological features and the size of the neoplasms was associated with the biological behavior. The results of this study described predispositions and verified the importance of different types of skin neoplasms in dogs in the region being studied.(AU)

O objetivo deste estudo foi determinar a prevalência e as características epidemiológicas das neoplasias cutâneas em cães na região metropolitana de Goiânia, Goiás. Foram analisados os diagnósticos de um laboratório do setor privado de 2011 a 2016. Mastocitoma, hemangiossarcoma, carcinoma de células escamosas, melanoma maligno e hemangioma representaram os principais diagnósticos. A maioria dos casos ocorreram em cães de raças definidas, fêmeas e com idade >8 anos. American Pit Bull Terrier e Poodle foram as raças mais encontradas. As neoplasias acometeram principalmente regiões de membros e cabeça. Pela análise de correspondência múltipla, associou-se os grupos de neoplasias com diferentes características epidemiológicas e o tamanho da neoplasia com o comportamento biológico. A comparação dos resultados com pesquisas prévias possibilitou confirmar predisposições previamente descritas e verificar a importância dos diferentes tipos de neoplasias cutâneas em cães na região estudada.(AU)

Canine cutaneous neoplasms in the metropolitan region of Goiânia, Goiás state, Brazil / Neoplasias cutâneas caninas na região metropolitana de Goiânia, Goiás, Brasil

ABSTRACT: The present study aimed to describe the occurrence and epidemiological features of skin neoplasms diagnosed in dogs in the metropolitan region of Goiânia, Goiás state, Brazil. Diagnoses from dog biopsies from 2011 to 2016 provided by a private veterinary pathology laboratory were analyzed. The main diagnoses were mast cell tumor, hemangiosarcoma, squamous cell carcinoma, malignant melanoma, and hemangioma. Highest frequency of neoplasms was found in female dogs, dogs aged > 8 years, and purebred dogs, particularly the American Pit Bull Terriers and the Poodles. Most common sites affected by the neoplasms were the limb and the head. Using multiple correspondence analysis, groups of neoplasms were found to be associated with different epidemiological features and the size of the neoplasms was associated with the biological behavior. The results of this study described predispositions and verified the importance of different types of skin neoplasms in dogs in the region being studied.(AU)

O objetivo deste estudo foi determinar a prevalência e as características epidemiológicas das neoplasias cutâneas em cães na região metropolitana de Goiânia, Goiás. Foram analisados os diagnósticos de um laboratório do setor privado de 2011 a 2016. Mastocitoma, hemangiossarcoma, carcinoma de células escamosas, melanoma maligno e hemangioma representaram os principais diagnósticos. A maioria dos casos ocorreram em cães de raças definidas, fêmeas e com idade >8 anos. American Pit Bull Terrier e Poodle foram as raças mais encontradas. As neoplasias acometeram principalmente regiões de membros e cabeça. Pela análise de correspondência múltipla, associou-se os grupos de neoplasias com diferentes características epidemiológicas e o tamanho da neoplasia com o comportamento biológico. A comparação dos resultados com pesquisas prévias possibilitou confirmar predisposições previamente descritas e verificar a importância dos diferentes tipos de neoplasias cutâneas em cães na região estudada.(AU)

Cutaneous metastatic melanoma in a Siberian tiger (Panthera tigris altaica) - case report / Melanoma cutâneo metastático em um tigre-siberiano (Panthera tigris altaica) - relato de caso

A male 15-year-old captive Siberian tiger (Panthera tigris altaica) developed pelvic limb hypermetry over the past 10 years. Recently, an ulcerated black nodule located caudally to the right ear was observed. The animal was submitted to surgery for removing the tumor, but died during anesthetic recovery. At necropsy, another infiltrative nodule was observed caudally to the right ear. Histologically, both nodules corresponded to melanocytic neoplasia, varying from heavily pigmented to amelanotic, with metastasis to mediastinal lymph nodes, spleen and lung. Lipofuscinosis and corpora amylacea were histologically observed in the central nervous system. Macroscopic and histologic findings confirmed the diagnosis of skin metastatic melanoma in a captive adult Siberian tiger.(AU)

Um tigre-siberiano (Panthera tigris altaica) de cativeiro, macho, de 15 anos de idade, apresentou hipermetria dos membros pélvicos nos últimos 10 anos, e recentemente, foi observado um nódulo preto e ulcerado caudalmente à orelha direita. O animal foi submetido à cirurgia para remoção do nódulo e morreu durante a recuperação anestésica. À necropsia, outro nódulo infiltrativo, foi detectado caudalmente a orelha direita. Histologicamente, ambos os nódulos correspondiam à neoplasia melanocítica, com células variando de fortemente pigmentadas a amelanóticas, com metástase para linfonodos mediastinais, baço e pulmão. Havia lipofucsinose e corpora amilácea no sistema nervoso central. Os achados macroscópicos e histológicos confirmam o diagnóstico de melanoma cutâneo metastático em um tigre-siberiano adulto de cativeiro.(AU)

Cutaneous metastatic melanoma in a Siberian tiger (Panthera tigris altaica) - case report / Melanoma cutâneo metastático em um tigre-siberiano (Panthera tigris altaica) - relato de caso

A male 15-year-old captive Siberian tiger (Panthera tigris altaica) developed pelvic limb hypermetry over the past 10 years. Recently, an ulcerated black nodule located caudally to the right ear was observed. The animal was submitted to surgery for removing the tumor, but died during anesthetic recovery. At necropsy, another infiltrative nodule was observed caudally to the right ear. Histologically, both nodules corresponded to melanocytic neoplasia, varying from heavily pigmented to amelanotic, with metastasis to mediastinal lymph nodes, spleen and lung. Lipofuscinosis and corpora amylacea were histologically observed in the central nervous system. Macroscopic and histologic findings confirmed the diagnosis of skin metastatic melanoma in a captive adult Siberian tiger.(AU)

Um tigre-siberiano (Panthera tigris altaica) de cativeiro, macho, de 15 anos de idade, apresentou hipermetria dos membros pélvicos nos últimos 10 anos, e recentemente, foi observado um nódulo preto e ulcerado caudalmente à orelha direita. O animal foi submetido à cirurgia para remoção do nódulo e morreu durante a recuperação anestésica. À necropsia, outro nódulo infiltrativo, foi detectado caudalmente a orelha direita. Histologicamente, ambos os nódulos correspondiam à neoplasia melanocítica, com células variando de fortemente pigmentadas a amelanóticas, com metástase para linfonodos mediastinais, baço e pulmão. Havia lipofucsinose e corpora amilácea no sistema nervoso central. Os achados macroscópicos e histológicos confirmam o diagnóstico de melanoma cutâneo metastático em um tigre-siberiano adulto de cativeiro.(AU)