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Neurofibromas are neoplasms derived from nerve bundles and are frequent in humans but not common in animals. This report described the macroscopic, histologic, and immunohistochemistry findings of an orbitofacial neurofibroma in a sow. The sow presented left eyelids with marked expansion, associated with severe ectropion and reddening of both conjunctival mucosae. The mass on the cutting surface was homogeneous, with a light tan, and shiny, measuring 9.0 x 7.0 x 7.0 cm in width, compressing the eyeball. Microscopically, there was paucicellular neoplastic proliferation of elongated cells amid the accentuated myxoid matrix. There were multifocal areas where well-differentiated nervous fascicles and skeletal musculature were seen. Neoplastic cells were immunostained positive for GFAP, neurofilament, S-100, Sox-10, and vimentin. Cytokeratin showed immunolabeling around primitive nerve bundles and desmin around neoformed vessels and muscle bundles within the tumor. Orbitopalpebral and orbitofacial neurofibroma, despite being common in humans, have not been described in domestic pigs and should be considered as a differential diagnosis in eyelid tumors in pigs.

Neurofibromas são neoplasias derivadas dos feixes nervosos e são frequentes em humanos, mas incomuns em espécies animais domésticos. Esse relato tem como objetivo descrever os achados macroscópicos, histológicos e imuno-histoquímicos de um neurofibroma orbitofacial em uma matriz suína. O animal apresentava as pálpebras esquerdas acentuadamente expandidas, associada a severo ectrópio e avermelhamento de ambas as mucosas conjuntivais. A tumoração palpebral, na superfície de corte, era homogênea, levemente acastanhada e brilhante, medindo 9,0 x 7,0 x 7,0 cm, e comprimia o globo ocular. Microscopicamente foi observada uma proliferação neoplásica pobremente celular de células alongadas no meio de uma acentuada quantidade de matriz mixoide. Havia áreas intratumorias multifocais onde fascículos nervosos bem diferenciados e musculatura esquelética foram observados. As células neoplásicas foram positivas na imuno-histoquímica para GFAP, neurofilamento, S-100, Sox-10 e vimentina. Citoqueratina mostrou uma imunomarcação ao redor de feixes nervosos primitivos e desmina ao redor de vasos neoformados e feixes musculares dentro do tumor. O neurofibroma orbitofacial, apesar de comum em humanos, nunca foi descrito em suínos domésticos e deve ser considerado um diagnóstico diferencial para neoplasias palpebrais em suínos.

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Background: Hemangiosarcoma (HSA) is a malignant neoplasm arising from the endothelial cells of blood vessels. It has fast growth, and severe local infiltration and metastasis power, in addition to risk of hemorrhage due to the fragility of its vessels. HSA develops in dogs aged 8 to 13 years but can affect younger animals too. Ocular involvement in HSA is rare, but when identified, the third eyelid and bulbar conjunctiva close to the limbus are the most affected sites by this neoplasm. This study aimed to report the clinicopathological aspects of a case of HSA in the third eyelid of an American Pit Bull Terrier breed. Case: A 10-year-old male American Pit Bull Terrier with a history of a red hemorrhagic mass on the third eyelid of the left eye was examined at a veterinary clinic. On physical examination, the animal showed signs of ocular discomfort and bleeding. On ophthalmologic examination, a raised red mass, approximately 2 cm in diameter, was identified on the anterior surface of the third eyelid. The mass was surgically excised. The excised tissue fragment was fixed in 10% buffered formalin solution for 24 h and sent for histopathological examination. Macroscopically, the fragment was irregular, soft, and brownish and measured 2.0 × 1.0 × 0.5 cm. Histologically, proliferation of non-delimited and non-encapsulated atypical endothelial cells, which were organized in vascular arrangements forming small lakes filled with red blood cells, was observed. The cells exhibited elongated and basophilic cytoplasm, oval nuclei with coarse chromatin, and evident nucleoli. Moderate anisocytosis and anisocariosis were observed, with no mitotic figures. Epithelial hyperplasia with mild mixed inflammatory infiltrate was noted. Surgical margins were compromised. Sections of neoplastic tissue were processed...

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Background: Eye neoplasms are infrequent in felines and usually affect the eyelids. Squamous cell carcinoma (SCC) is a neoplasm that occurs owing to recurrent lesions caused by solar radiation and affects the margins of the ears, eyelids, nose and lips of animals with light-colored coat. The clinical signs consist of ulcerated, crusty lesions that may form masses. The diagnosis is established by means of histopathological analysis, and the prognosis depends on the area affected and tumor infiltration. This work aimed to describe a case of SCC in the eyelid with invasion of the eye and its adnexa in a cat, highlighting clinical aspects and the importance of the anatomopathological examination. Case: A female mixed breed senile cat that had been rescued from the streets was brought in for examination. Dehydration and a low body condition score were observed at the general clinical examination. A physical inspection revealed the presence of an ulcerated periocular lesion on the eyelid; the right eye exhibited increased size and loss of definition of its internal structures. The presence of malodorous cerumen in the right ear canal, a tilted head, and walking in circles to the right were also noted. A dysplastic epithelium along with neutrophilic inflammation was observed at the cytopathological analysis. The treatment instituted consisted of administration of antibacterial and anti-inflammatory drugs, and cleaning of the ear. On the follow-up appointment, 2 days later, the patient's condition had worsened and in spite of the supportive therapy administered, the animal died. An anatomopathological study of the body identified, in addition to the alterations in the eyelid and the eye mentioned above, a traumatic lesion with perforation of the mandibular bone, and presence of a brownish content with caseous consistency in the right ear canal. After visualization of the microscopic alterations, the diagnosis established was squamous cell carcinoma of the eyelid with metastases in the optical nerve and choroid blood vessels. Discussion: Squamous cell carcinoma is one of the most common epithelial neoplasms in felines, and can occur in any region of the face; however, the eyelids and the eyes are less frequently affected, which confirms that the case reported here is uncommon. SCC has a higher incidence in female cats older than 10 years of age with light-colored coat and highly exposed to ultraviolet radiation. The case reported here exhibited these characteristics, as the patient had been rescued from the streets where exposition to sunlight is intense. The clinical presentation was consistent with that described in other works, with ulcerated crusty lesions on the eyelid and the nose. Vestibular syndrome, as inferred from the tilted head and circular gait (walking in circles to the right), could be explained by internal otitis, which was observed at necropsy. The cytological analysis of the eye lesion demonstrated the presence of a neutrophilic inflammatory process along with a dysplastic or immature squamous epithelium, which prompted for therapy using antimicrobial and anti-inflammatory drugs. The definitive diagnosis was established with basis on the histopathological analysis, which revealed a pattern of neoplastic cells arranged in clusters or strands connected to the epidermal surface, and the presence of "keratin pearls" consistent with SCC affecting not only the eyelid and the eye, but also invading the optical nerve and the choroid blood vessels. The prognosis was unfavorable owing to the advanced stage of the tumor and concomitant diseases. Even though the development of SCC in the eyelid is relatively common, the occurrence of metastasis in the eye adnexa is rare in felines. An anatomopathological study was required to establish the diagnosis of SCC as the patient's clinical history data were scarce.

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Background: Peripheral nerve sheath tumors are most commonly found on the head and neck regions of both dogs and people. Schwannomas are rarely observed in ophthalmic areas. When they occur, ocular Schwannomas are usually located in the orbit, uveal tract and conjunctiva. The occurrence of uveal schwannoma, a subset of PNST has been well documented in the veterinary literature. PNST has never been observed in the eyelids of dogs. Therefore, the present report aimed to describe the surgical treatment and outcome of a PNST located in the upper eyelid of a dog. Case: A 9-year-old, spayed female mixed-breed dog was referred for evaluation of a large mass involving the right upper eyelid for a duration of approximately one month. The inspection revealed sero-sanguinolent discharge and an oval-shaped mass occupying more than 70% of the right upper eyelid. A presumptive diagnosis of eyelid neoplasia was considered most likely. Excision of the entire mass with a 2 cm margin was performed. The third eyelid and dorso-medial bulbar conjunctiva were also removed. Upper eyelid reconstruction was performed based on a similar technique previously described in cats (lip-to-lid flap). As a result, neoplastic spindle cells exhibited immunoreactivity for S100 and intense cytoplasmic staining for vimentin, supporting the diagnosis of schwannoma. Fifteen days later, the margins of the subdermal pattern flap were healed and skin sutures were removed. On the last follow-up, 9 months post-surgery, the dog was visual, and the flap was well incorporated and covered the ocular surface. Ten months later, another large mass arising from the right inferior palpebral conjunctiva was observed. Once ultrasound revealed orbital invasion exenteration combined with orbitectomy were performed, and the defect was covered with an auricular axial pattern flap. The second tumor had the same histological and immunohistochemical characteristics of the first mass. Both tumors expressed Ki67; however, the PI in the second mass was higher (7.9%) than the first (3.4%). Discussion: Reported eyelid neoplasms in dogs include adenomas and adenocarcinomas of the meibomian glands, melanomas, fibroma, fibrosarcoma, histiocytoma, mastocytoma, lipomas, papillomas, and squamous cell carcinomas. To the author's knowledge, however, this is the first case description of a PNST affecting the eyelid in a dog. The histologic distinction between PNSTs and other spindle cell tumors, including myxosarcoma, fibrosarcoma, leiomyosarcoma, hemangiopericytoma, and melanoma can be challenging and requires immunohistochemical stainin. S100 is an acidic protein that identifies various nervous tissue cells, including Schwann cells, and the majority of canine PNSTs diffusely express this molecule. As in the case presented here, neoplastic cells of different ocular and adnexal structures were also positive for S100 and vimentin in all PNSTs previously reported in the veterinary literature. This is the first report of PNST affecting the eyelid in a dog. The lip-to-lid flap is a feasible technique to reconstruct the upper eyelid following wide surgical removal of a tumor in dogs. However, the authors suggest radical surgery combining orbitectomy, exenteration and a miocutaneous flap if PNST is diagnosed in the eyelids of dogs. They also caution once recurrence is possible and can be more aggressive.(AU)

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O melanoma é uma neoplasia maligna de melanócitos, os quais produzem a melanina responsável pela pigmentação da pele, descrito em várias espécies animais e em seres humanos. Em equinos, esse tipo tumoral representa grande parte dos comprometimentos cutâneos, principalmente em animais de pelagem tordilha; porém não se observa predileção racial e sexual, sendo a idade considerada um agravante na malignidade. Esta afecção acomete principalmente as regiões de cauda, períneo, orelhas e olhos, e ocasionalmente se desenvolvem em órgãos genitais; sendo que o curso clínico varia desde a invasão de órgãos até a disseminação metastática. Caracterizam-se por lesões firmes, nodulares, únicas ou múltiplas, de tamanhos e coloração variados, infiltrativas, podendo ocorrer ulcerações. Os sinais clínicos demonstrados pelos pacientes acometidos são variáveis, dependendo da localização tumoral. Em animais, o diagnóstico de melanoma está relacionado a um prognóstico desfavorável, pois, em geral, o tumor é detectado tardiamente, quando já houve infiltração local ou formação de metástases. Este trabalho tem como objetivo relatar um caso relacionado a melanoma de terceira pálpebra em um equino macho, com 13 anos de idade, raça Puro Sangue Lusitano (PSL), pelagem tordilha. O animal apresentava nódulos de tamanhos consideráveis na terceira pálpebra do olho direito, de coloração enegrecida, sendo submetido a procedimento cirúrgico para a remoção total do mesmo. O animal foi submetido a um protocolo pós-cirúrgico com antibioticoterapia local na forma de colírio (Ciprofloxacina 0,3mg ou 02 gotas), quatro vezes ao dia, durante dez dias e também sistêmica (Benzilpenicilina G Procaína 4000UI/Kg/PV) por via intramuscular, uma vez ao dia, durante cinco dias...

Melanoma is a malignant neoplasm of melanocytes which produce melanin, responsible for skin pigmentation, described in various animal species and in humans. In equines, this tumor type represents a large part of the mainly in fur animals; but there is no racial and sexual predilection, and age is considered an aggravating factor in malignancy. This condition mainly affects the tail, perineum, auricular and ocular regions and occasionally develops in the genital organs; and the clinical course varies from invasion of organs to metastatic dissemination. It is characterized by firm, nodular, single or multiple lesions of varying infiltrative sizes and staining, and ulcerations may occur. The clinical signs demonstrated by the affected patients are variable, depending on the tumor location. In animals, the diagnosis of melanoma is related to an unfavorable prognosis, since, in general, the tumor is detected late, when there has been local infiltration or formation of metastases. The aim of this study is to report a case related to third eyelid melanoma in a 13 year - old male Purebred Lusitano (PSL) equine breed. The animal presented nodules of considerable size in the third eyelid of the right eye, of blackened color, being submitted to surgical procedure for the total removal of the same one. The animal was submitted to a post-surgical protocol with local antibiotic therapy in the form of eye drops (Ciprofloxacin 0.3mg or 2 drops), four times a day for ten days and also systemic (Benzylpenicillin G Procaine 4000UI/Kg/PV) intramuscularly once daily for five days. As an anti-inflammatory protocol, it was used topically, eye drops (Flurbiprofen Sodium 0.03mg or 2 drops), four times a day for ten days and intravenously (Fenilbutazone 4.0mg/Kg/PV), once a day during five days, responding satisfactorily to the treatment.

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O melanoma é uma neoplasia maligna de melanócitos, os quais produzem a melanina responsável pela pigmentação da pele, descrito em várias espécies animais e em seres humanos. Em equinos, esse tipo tumoral representa grande parte dos comprometimentos cutâneos, principalmente em animais de pelagem tordilha; porém não se observa predileção racial e sexual, sendo a idade considerada um agravante na malignidade. Esta afecção acomete principalmente as regiões de cauda, períneo, orelhas e olhos, e ocasionalmente se desenvolvem em órgãos genitais; sendo que o curso clínico varia desde a invasão de órgãos até a disseminação metastática. Caracterizam-se por lesões firmes, nodulares, únicas ou múltiplas, de tamanhos e coloração variados, infiltrativas, podendo ocorrer ulcerações. Os sinais clínicos demonstrados pelos pacientes acometidos são variáveis, dependendo da localização tumoral. Em animais, o diagnóstico de melanoma está relacionado a um prognóstico desfavorável, pois, em geral, o tumor é detectado tardiamente, quando já houve infiltração local ou formação de metástases. Este trabalho tem como objetivo relatar um caso relacionado a melanoma de terceira pálpebra em um equino macho, com 13 anos de idade, raça Puro Sangue Lusitano (PSL), pelagem tordilha. O animal apresentava nódulos de tamanhos consideráveis na terceira pálpebra do olho direito, de coloração enegrecida, sendo submetido a procedimento cirúrgico para a remoção total do mesmo. O animal foi submetido a um protocolo pós-cirúrgico com antibioticoterapia local na forma de colírio (Ciprofloxacina 0,3mg ou 02 gotas), quatro vezes ao dia, durante dez dias e também sistêmica (Benzilpenicilina G Procaína 4000UI/Kg/PV) por via intramuscular, uma vez ao dia, durante cinco dias...(AU)

Melanoma is a malignant neoplasm of melanocytes which produce melanin, responsible for skin pigmentation, described in various animal species and in humans. In equines, this tumor type represents a large part of the mainly in fur animals; but there is no racial and sexual predilection, and age is considered an aggravating factor in malignancy. This condition mainly affects the tail, perineum, auricular and ocular regions and occasionally develops in the genital organs; and the clinical course varies from invasion of organs to metastatic dissemination. It is characterized by firm, nodular, single or multiple lesions of varying infiltrative sizes and staining, and ulcerations may occur. The clinical signs demonstrated by the affected patients are variable, depending on the tumor location. In animals, the diagnosis of melanoma is related to an unfavorable prognosis, since, in general, the tumor is detected late, when there has been local infiltration or formation of metastases. The aim of this study is to report a case related to third eyelid melanoma in a 13 year - old male Purebred Lusitano (PSL) equine breed. The animal presented nodules of considerable size in the third eyelid of the right eye, of blackened color, being submitted to surgical procedure for the total removal of the same one. The animal was submitted to a post-surgical protocol with local antibiotic therapy in the form of eye drops (Ciprofloxacin 0.3mg or 2 drops), four times a day for ten days and also systemic (Benzylpenicillin G Procaine 4000UI/Kg/PV) intramuscularly once daily for five days. As an anti-inflammatory protocol, it was used topically, eye drops (Flurbiprofen Sodium 0.03mg or 2 drops), four times a day for ten days and intravenously (Fenilbutazone 4.0mg/Kg/PV), once a day during five days, responding satisfactorily to the treatment.(AU)

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Palpebral neoformations are very common in dogs, and may have different etiological origins, such as melanoma and squamous papilloma, localization generally directly affects ocular physiology, the treatment of choice is radical surgical excision, with a lower chance of recurrence, of the ideal surgical techniques is H-plasty, as this promotes a good margin of safety and reduces tension by tissue loss.

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Palpebral neoformations are very common in dogs, and may have different etiological origins, such as melanoma and squamous papilloma, localization generally directly affects ocular physiology, the treatment of choice is radical surgical excision, with a lower chance of recurrence, of the ideal surgical techniques is H-plasty, as this promotes a good margin of safety and reduces tension by tissue loss.(AU)

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The aim of this work was to describe an eyelid neoplasm in wild birds, since the veterinary literature has little information concerning the aspects of the oncologic clinic in wild species. In the clinical exam, it was observed a single mass in the upper right eyelid of the Pheugopedius genibarbis a, with rough surface, cauliflower aspect, of dark-red coloration . For the histopathological diagnosis, an incisional biopsy of the lesion was done , with the fragment fixed in 10% buffered neutral formalin, processed by the method of inclusion in paraffin , cut to 4µm sections and stained with H&E . The histopathological findings revealed elongated dermal papillae covered by acanthotic epidermis, as well as thickness of the stratum spinosum . In the stratum spinosum, it was observed the presence of cells with vacuolated cytoplasm and nucleus slightly dislocated to the center of the cell, which increases in proportion when closer to the granular layer, an indication of hydropic degeneration , there were In the basal layer it is possible to notice the presence of the normal mitotic figures.. Based on the macro and microscopic characteristics, that neoplasm was diagnosed as an eyelid papilloma.

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The aim of this work was to describe an eyelid neoplasm in wild birds, since the veterinary literature has little information concerning the aspects of the oncologic clinic in wild species. In the clinical exam, it was observed a single mass in the upper right eyelid of the Pheugopedius genibarbis a, with rough surface, cauliflower aspect, of dark-red coloration . For the histopathological diagnosis, an incisional biopsy of the lesion was done , with the fragment fixed in 10% buffered neutral formalin, processed by the method of inclusion in paraffin , cut to 4µm sections and stained with H&E . The histopathological findings revealed elongated dermal papillae covered by acanthotic epidermis, as well as thickness of the stratum spinosum . In the stratum spinosum, it was observed the presence of cells with vacuolated cytoplasm and nucleus slightly dislocated to the center of the cell, which increases in proportion when closer to the granular layer, an indication of hydropic degeneration , there were In the basal layer it is possible to notice the presence of the normal mitotic figures.. Based on the macro and microscopic characteristics, that neoplasm was diagnosed as an eyelid papilloma.(AU)

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Fibropapillomatosis (FP) is a multifactorial disease that affects all species of marine turtles, including green turtles Chelonia mydas (Linnaeus, 1758). It is characterised by the development of internal or external tumours that, depending on their locations and sizes, may intensely impact the health condition of sea turtles. The goal of this study was to characterise the disease in C. mydas found in a foraging area in southeastern Brazil, evaluate the prevalence in this region, and correlate presence and absence, size, body distribution, number of tumours, and disease severity with biometric variables of the captured green turtles. Between 2008 and 2014, the prevalence rate of FP was 43.09%, out of 246 green turtles. The size of the animals with FP was relatively greater than animals without tumours, and the prevalence of FP increased with animal size, peaking in the 60-80 cm size class. From 2013 to 2014, gross evaluation of fibropapillomas was performed. The number of tumours per turtle ranged from 1 to 158. The size of tumours ranged from <1 cm (Size A) to >10 cm (Size D); Size A tumours and turtles slightly affected by the disease (Score 1) predominated. Tumour progression (72.1%) and regression (32.8%) were seen in some recaptured individuals (n = 61). Moreover, 24.6% of these turtles showed both progressions and regressions of tumours.

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Neoplasias oculares causam desconforto, problemas de visão e podem refletir doenças sistêmicas. Um estudo retrospectivo foi realizado para identificar e analisar neoplasmas oculares e de anexos obtidos por biópsias enviadas ao Setor de Patologia Veterinária (SPV) da Universidade Federal do Rio Grande do Sul (UFRGS). Durante o período de janeiro de 2009 a dezembro de 2014 realizou-se 265 diagnósticos de neoplasmas oculares e de anexos, destes 87,5% na espécie canina e em 12,5% na espécie felina. As neoplasias ocorreram mais em animais com idade superior a 12 meses e idosos, e os cães (52/232) e gatos (21/33) sem raça definida foram os mais acometidos. A pálpebra foi o local mais acometido na espécie canina (164/232) e felina (20/33), seguida pela terceira pálpebra em cães (20/232) e órbita nos felinos (5/33). O tumor mais diagnosticado nos cães foi o adenoma meibomiano (82/232) e nos gatos o carcinoma de células escamosas (10/33), ambos em pálpebras. Foram identificados nos cães 24 tipos tumorais e nos gatos 16. Em caninos as neoplasias benignas representaram o maior número de diagnósticos (56%) sendo que em felinos o maior número de casos foi de neoplasias malignas (75,8%)...

Ocular neoplasms cause discomfort, loss of vision or may also reflect systemic diseases. A retrospective study has been performed to identify and analyze ocular and annexes neoplasms obtained by biopsies sent to the Sector of Veterinary Pathology at the Federal University of Rio Grande do Sul (SPV/ UFRGS). 265 diagnoses of ocular and annexes neoplasms, 87.5% in canine species and 12.5% in feline species, were made from January 2009 to December 2014. Neoplasms occurred more in animals over the age of 12 months and animals of old age, dogs (52/232) and cats (21/33) mixed breed were the most affected. The eyelid was most commonly affected in dogs (164/232) and feline (20/33), followed by the third eyelid in dogs (20/232) and eye orbit in cats (5/33). The most common tumor diagnosed was meibomian adenoma in dogs (82/232) and squamous cell carcinoma in cats (10/33) both in the eyelids. Twenty four tumor types have been identified in dogs and 16 in cats. Benign neoplasms in dogs represented the largest number of diagnosis (56%) whereas in cats, there were more cases of malignant neoplasms (75.8%)...

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Neoplasias oculares causam desconforto, problemas de visão e podem refletir doenças sistêmicas. Um estudo retrospectivo foi realizado para identificar e analisar neoplasmas oculares e de anexos obtidos por biópsias enviadas ao Setor de Patologia Veterinária (SPV) da Universidade Federal do Rio Grande do Sul (UFRGS). Durante o período de janeiro de 2009 a dezembro de 2014 realizou-se 265 diagnósticos de neoplasmas oculares e de anexos, destes 87,5% na espécie canina e em 12,5% na espécie felina. As neoplasias ocorreram mais em animais com idade superior a 12 meses e idosos, e os cães (52/232) e gatos (21/33) sem raça definida foram os mais acometidos. A pálpebra foi o local mais acometido na espécie canina (164/232) e felina (20/33), seguida pela terceira pálpebra em cães (20/232) e órbita nos felinos (5/33). O tumor mais diagnosticado nos cães foi o adenoma meibomiano (82/232) e nos gatos o carcinoma de células escamosas (10/33), ambos em pálpebras. Foram identificados nos cães 24 tipos tumorais e nos gatos 16. Em caninos as neoplasias benignas representaram o maior número de diagnósticos (56%) sendo que em felinos o maior número de casos foi de neoplasias malignas (75,8%).(AU)

Ocular neoplasms cause discomfort, loss of vision or may also reflect systemic diseases. A retrospective study has been performed to identify and analyze ocular and annexes neoplasms obtained by biopsies sent to the Sector of Veterinary Pathology at the Federal University of Rio Grande do Sul (SPV/ UFRGS). 265 diagnoses of ocular and annexes neoplasms, 87.5% in canine species and 12.5% in feline species, were made from January 2009 to December 2014. Neoplasms occurred more in animals over the age of 12 months and animals of old age, dogs (52/232) and cats (21/33) mixed breed were the most affected. The eyelid was most commonly affected in dogs (164/232) and feline (20/33), followed by the third eyelid in dogs (20/232) and eye orbit in cats (5/33). The most common tumor diagnosed was meibomian adenoma in dogs (82/232) and squamous cell carcinoma in cats (10/33) both in the eyelids. Twenty four tumor types have been identified in dogs and 16 in cats. Benign neoplasms in dogs represented the largest number of diagnosis (56%) whereas in cats, there were more cases of malignant neoplasms (75.8%).(AU)

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PURPOSE: To detect the occurrence and expression of the suppressor gene p53 and of the oncogene c-Myc in eyelid tumors of dogs using the PCR, RT-PCR, PCR-ELISA and RT-PCR-ELISA techniques. These genes have not been described in dog eyelid tumors before. METHODS: Nine samples of eyelid or third eyelid epithelial tumors were obtained from the archives of the Department of Veterinary Pathology. Tumor diagnosis was confirmed by evaluation of hematoxylin-eosin stained sections, and immunohistochemistry for cytokeratin AE1/AE3 and vimentin V9. A canine mammary tumor was used for positive control. Agarose gel electrophoresis, PCR-ELISA and RT-PCR-ELISA were used to detect p53 and c-Myc genes. RESULTS: The occurrence of p53 was detected in most of the eyelid tumors and third eyelid tumors studied (88.8%, n = 8) and was expressed in 75% of the positive samples, as indicated by ELISA. The c-Myc gene was found in 77.7% (n = 7) of the samples and was expressed in eight samples. CONCLUSIONS: Eyelid and third eyelid tumors of dogs express both the p53 and the c-Myc genes as shown by PCR and RT-PCR. However, PCR ELISA and RT-PCR ELISA were more efficient in assessing occurrence and expression of these genes because they identified amplified products that were not detected by agarose gel electrophoresis.

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