Mutations of the c-KIT gene in canine mast cell tumors and respective nodal metastases classified according to mast cell infiltration / Mutações no gene c-KIT em mastocitomas caninos e respectivas metástases nodais classificados segundo a infiltração de mastócitos

The molecular background of canine mast cell tumors (MCT) has been extensively investigated; however, the dynamic molecular changes that occur during carcinogenesis and metastasis are not fully understood. This study aimed to evaluate the incidence of mutations in the c-KIT proto-oncogene in canine MCTs and relative draining regional lymph nodes. Suspected or confirmed lymph node metastasis was classified accordingly to the HN Weishaar classification. The study included 34 dogs diagnosed with MCT; 19 patients were enrolled prospectively. These dogs had the primary MCT and regional lymph node resected and analyzed simultaneously. The second group was evaluated retrospectively and included fifteen patients resectioning the primary MCT without evaluation of regional lymph node. Analyzes of c-KIT mutation were performed for all primary MCTs and, in the first group, compared between primary MCT and HN-classified metastasis. Internal tandem duplications (ITD) in exon 11 of the c-KIT gene were detected in 20% of patients. Ten of the nineteen patients (52%) in the first group presented mast cell infiltration in the regional lymph node, and ITD in exon 11 of the c-KIT gene was detected in five and two dogs from Groups 1 and 2, respectively. ITD c-KIT mutations are common in canine MCT and may be found in the draining lymph node metastases/mast cell infiltrates in the absence of mutation of the primary tumor. Evaluation of c-KIT mutation in the primary tumor and metastases may be informative for defining both prognosis and therapeutic options in MCT cases.

O perfil molecular do mastocitoma (MCT) tem sido bastante investigado, no entanto as dinâmicas moleculares que ocorrem durante a carcinogênese e metástase desta neoplasia não estão bem esclarecidas. O objetivo desse estudo foi avaliar a incidência de mutações no proto-oncogene c-KIT em MCTs caninos e respectivos linfonodos regionais. Os casos suspeitos ou confirmados de metástase para os linfonodos, foram classificados de acordo com a classificação HN de Weishaar. O estudo incluiu 34 cães diagnosticados com MCT e, desses, 19 pacientes foram avaliados de maneira prospectiva, em que o tumor primário e o linfonodo regional foram ressecados e analisados simultaneamente. O segundo grupo foi avaliado retrospectivamente e incluiu quinze pacientes que tiveram ressecção do MCT primário sem avaliação de linfonodo regional. A análise da mutação c-KIT foi realizada para todos os MCTs primários e, no primeiro grupo, comparados entre MCT primário e metástase classificada pelo sistema HN. Duplicações internas em tandem (DIT), no exon 11 do gene c-KIT, foram detectadas em um total de 20% dos pacientes. Dez dos dezenove pacientes (52%) do primeiro grupo apresentavam infiltração de mastócitos no linfonodo regional, e DIT no exon 11 do gene c-KIT foram identificadas em cinco e dois cães dos Grupos 1 e 2, respectivamente. Mutações do tipo DIT no gene c-KIT são comuns no MCT canino e podem estar presentes nas metástases/infiltrados de mastócitos na ausência de mutação do tumor primário. A avaliação da mutação no gene c-KIT no tumor primário e metástases pode ser informativa para definir tanto o prognóstico quanto as opções terapêuticas em casos de MCT.

Mastocitoma cutâneo canino após mastocitose acidental induzida por opioide: Relato de caso / Canine cutaneous mastocytoma after accidental opioid-induced mastocytosis: Case report

A aproximação entre petse tutores está cada vez mais presente na rotina atual das residências familiares. Essa aproximação aumenta a observação de quaisquer alterações físicas ou comportamentais dos animais levando-o a buscar um médico veterinário quando necessário. O papel do clínico, oncologista e do patologista veterinário vem a ser de extrema importância para detecção das neoplasias em suas fases iniciais. A utilização dos meios de diagnósticos complementares para os casos de neoplasias é de fundamental importância para ter ciência do prognóstico do animal e de qual tratamento será o melhor tratamento para os casos abordados. O mastocitoma é a neoplasia cutânea mais frequente do cão, é uma neoplasia maligna e sua etiologia é pouco compreendida. Independente do sexo, atingem machos e fêmeas, porém se apresentam de forma mais agressiva em machos. O diagnóstico, geralmente é estabelecido por meio de exames complementares, associados aos sinaisclínicos, devendo sempre prezar pelo diagnóstico precoce para que haja maior êxito no tratamento.O exame citológico para o diagnóstico de mastocitoma é um dos métodos mais eficientes e de baixo custo, sendo complementado pelo exame histopatológico para agraduação de malignidade e estadiamento da doença. Preconiza-se a associação da cirurgia com o tratamento quimioterápico com terapia antiblástica e eletroquimioterapia para um melhor prognóstico. O objetivo deste trabalho foi relatar um caso de mastocitoma cutâneo após um erro primário de manejo clinico, em um canino, macho, nove anos, da raça American Pitbull Terrier, trazendo sua complexidade e bases dos meios de diagnóstico(AU)

The approximation between pets and tutors is increasingly present in the current routine of family homes. This approach increases the observation of physical or behavioral changes in animals, leading them to seek a veterinarian when necessary. The role of the clinician, oncologist and veterinary pathologist is extremely important for the detection of neoplasms in their early stages. The use of complementary diagnostic means for cases of neoplasms is of fundamental importance to be aware of the animal's prognosis and which treatment will be the best treatment for the cases examined. Mastocytoma is the most frequent skin neoplasm in dogs, it is a malignant neoplasm and its etiology is poorly understood. Regardless of gender, they affect males and females, but are more aggressive in males. The diagnosis is usually established through complementary exams, associated with clinical signs. Cytological examination for the diagnosis of mast cell tumor is an inexpensive method and one of the most efficient methods, being complemented by histopathological examination for its evolution of malignancy and disease staging, recommended the association of surgery with chemotherapy treatment with antiblastic therapy and electrochemotherapy for better prognoses. The aim of this study was to report a case of cutaneous mastocytoma after a primary error in clinical management, in a canine, male, nine years old, of the American Pitbull Terrier breed, bringing its complexity and bases of the means of diagnosis(AU)

Metastatic intranasal mastocytoma in a dog

Background: Mast cell tumors (MCTs) are neoplasms originating from mast cells, which can be well or poorly differentiated. They are considered the most commonly diagnosed malignant cutaneous neoplasm in dogs; however, intranasal forms are still little reported. Thus, this study seeks to report a case of unilateral intranasal MCT exhibiting submandibular lymph node metastasis. Case: A 11-year-old-and-4-month-old dog of undefined breed (UB), weighing 41 kg, was referred to the Veterinary Medical Teaching Hospital of the University of Passo Fundo (UPF), in the state of Rio Grande do Sul, Brazil. Presenting a clinical history of bilateral purulent nasal secretion, accompanied by sneezing in the two months prior to admission, in addition to vomiting and diarrhea. Auxiliary tests were requested, including skull X-ray, cytology of the nasal cavity with a swab, and collection of material from the submandibular lymph node directly through cytology with a needle. Cytological findings from the right nasal cavity were consistent with mast cell tumors (MCTs). Cytological analysis of the left nasal cavity was compatible with dysplasia/cellular reactivity. A heterogeneous population of cells was detected on cytology of the right submandibular lymph node. These findings were consistent with MCT lymph node metastasis. Skull radiography showed an increase in both opacity and soft tissue extension, surpassing the palate, from the canine tooth through the caudal region of the maxillary sinuses to the last molar, without bone destruction. The dog was then admitted for an abdominal ultrasound, which showed no changes in the spleen or liver. The leukocyte count showed mild lymphopenia and the presence of reactive lymphocytes. Through the buffy coat, the presence of rare round cells, compatible with circulating mast cells, was detected. Due to the biological behavior of the neoplasm and its anatomical location, the established therapy was based on the use of vinblastine and prednisolone. The patient did not show any clinical improvements. In a joint decision with the patient's guardian, the dog was euthanized. Discussion: Intranasal MCTs commonly present progressive and intermittent unilateral epitaxis, mucopurulent nasal discharge, dyspnea, and ocular discharge. Several anatomical sites were associated with more aggressive neoplastic phenotypes; those with an unfavorable prognosis were mainly those present in the oral and intranasal mucosa. Cytopathological examination is considered a highly sensitive method for the diagnosis of MCTs. Metastases are present in more than 90% of mucosal MCTs, usually affecting regional lymph nodes and associated with a poor prognosis. Radiography is considered a useful test in determining the size and location of tumors in the nasal cavity. Chemotherapy plays an important role in the treatment, especially in cases like the one described in this report, in which surgical excision is not possible due to the anatomical location of the neoplasm. Intranasal MCTs are uncommon in dogs. In this case, he presented aggressive, metastatic behavior and a poor response to antineoplastic therapy. Furthermore, due to the location of these tumors, they may be clinically similar to a number of other upper respiratory tract diseases, posing a diagnostic challenge. Therefore, it is essential that the search for differential diagnoses be carried out through auxiliary tests, such as cytology and imaging.

Epididymal primary mast cell tumor in a dog

Background: In the literature, there are a few descriptions of epididymis neoplasia in domestic animals, especially considering primary tumors. In the few reports found in literature, the lesions were a consequence of the invasion of testicular or paratesticular neoplasia, as a papillar carcinoma in a dog's and a bull's epididymis, and mesenchymal tumors - fibrome/ fibrosarcoma, leiomyoma/leiosarcome. On the other hand, mast cell tumors are the second most prevalent neoplasia in dogs in Brazil, affecting especially the skin. The aim of this report is to describe for the first time a low malignancy mast cell tumor in a mixed-breed dog's epididymis, without metastasis or recurrence in a 2-year follow-up period. Case: A 10-year-old male mixed-breed dog was presented for pre-surgical evaluation for elective orchiectomy. In the physical examination, an increase in the volume of approximately 2 cm with an irregular appearance was identified on palpation in the cranial pole of the left testis. In the trans surgical period, an increase in testicular volume (4 cm long x 2 cm wide) was observed, with a firm consistency in the region of the vas deferens with macroscopic changes in the region. The testis was sectioned, and the fragments were sent for histopathological evaluation in 10% buffered formaldehyde. There was a fairly cellular circumscribed neoplastic infiltrate, distributed in a sheet and separated by fibrovascular stroma, and rounded neoplastic cells with a moderate amount of basophilic cytoplasmic granulation, and discrete anisocytosis and anisokaryosis. The nuclei were rounded with vesicular chromatin with 1 or 2 distinct nucleoli. No mitosis figures were observed in 10 high power fields (400x). Few eosinophils were distributed throughout the neoplastic cell population. Immunohistochemistry demonstrated immunostaining for KIT protein with perimembranous staining in 95% of neoplastic mast cells, giving a KIT 1 pattern. There was no positive nuclear staining for Ki67 in any cell of the histological sections examined. A grade II mast cell tumor (low grade of malignancy) was diagnosed. After diagnosis, the animal underwent radiographic evaluation of the chest and abdominal ultrasound, and a new physical inspection in search of nodules, plaques, skin lesions, or subcutaneous masses. There were no metastases in the thorax and abdominal cavity, nor physical alterations, and it can be inferred that the epididymis was the primary site of the mast cell tumor. After 2 years of orchiectomy, there were no recurrences, and no chemotherapy treatment was performed. Discussion: Extracutaneous mast cell tumors are uncommon in animals, but have been reported in oral and nasal mucosa, nasopharynx, larynx, trachea, intestine, visceral lymph nodes, spleen, liver, spinal cord, intestine, ureter, conjunctiva, lung and more recently in tear gland of the third eyelid. However, in the authors' assessment, this is the first description of mast cell tumor in the epididymis in dogs. The diagnosis was established by histopathological examination, which revealed a grade II epididymal mast cell tumor and immunohistochemical evaluation (KIT and Ki-67) as being of low aggressiveness. The diagnosis of a primary tumor was confirmed since the staging was established after the histopathological diagnosis, involving chest radiography, abdominal ultrasound, cutaneous evaluation in search of nodules, plaques, cutaneous and subcutaneous lesions, and did not reveal other abnormalities or metastases not identified in the preoperative evaluation. In addition, immunostaining with KIT and Ki-67 reaffirmed the low degree of malignancy and the potential for metastases, which can be observed by the asymptomatic follow-up of the patient 2 years after the surgical excision.

Mastocitoma cutâneo em uma cadela / Cutaneous mast cell tumor in a bitch

Background: The diagnostic of neoplasia in dogs has risen significantly in the last years and this fact is mostly attributed to the longer life expectancy of these animals, which contributes to a greater chance of exposure to carcinogenic agents. In between the diverse tumors that could compromise skin, the mastocytoma is the third most commonly diagnosed neoplasia. It is characterized by being a form of neoplasia with round cells, these being the mast cells. The objective of the present study consisted in relating a case of cutaneous mastocytoma in a 7-year-old bitch mixed-breed treated at the Veterinary Medical Teaching Hospital of the University of Uberaba (UNIUBE) - Uberaba, MG, Brazil. Case: The bitch initially presented a localized nodule external to the right ear pinna with cytology test suggesting a mastocytoma. The nodule was surgically removed and, posteriorly, an histopatholgy was not requested. After 5 months since the emergence of the nodule and a month after its surgical resection, the tutor noticed the presence of a new growth in the ipsilateral cervical region to the previous nodule. At this moment, the responsible veterinarian decided to refer the animal to an oncologist. During the appointment with the oncologist, alterations such as hyporexia and anemia were related, and the presence of a nodule in the right cervical region measuring 4.5 to 4 cm of diameter was verified. Material for cytologic evaluation of the neoplasia was collected and again the result suggested a mastocytoma. The new tumor was also surgically removed but was then referred to histopathological evaluation for diagnostic confirmation, grading and evaluation of surgical margins. The tumor was classified as an infiltrative subcutaneous mastocytoma presenting, additionally, compromised surgical margins. After its excision, the association with a chemotherapy treatment using a protocol of Vimblastina 2 mg/m², i.v. in unique dosage per section, associated with Predinisona 1 mg/kg, v.o, SID was indicated. Each section was realized with an interval of 7 days in between. Only 2 chemotherapy sessions took place. Because of the worsening of the clinical condition associated with a very weakened animal the veterinarian opted for the euthanasia of the animal. Discussion: The diagnostic of mastocytoma must be realized through the association of cytology and histopathology, in case histopathological evaluation is needed to confirm the obtained cytology result, to grade the tumor and to evaluate the compromising of surgical margins. In this sense, it was observed that the bitch was submitted only to cytology diagnostic when it presented the nodule in the ear pavilion. Yet, at the second approach realized by the oncologist, it was possible to realize adequate diagnose methods. However, the animal was not submitted to clinical staging of the mastocytoma due to the non-authorization of the exam by the tutor. Such measure is very important, as it reflects directly in the treatment and prognostic of the animal. Thus, image exams such as abdominal ultrasonography and chest X-ray should have been realized, as well as cytological and histopathological evaluation of the regional lymph nodes, in order to search for metastasis points in these places. As the data suggests, the importance of clinical staging of animals affected by this neoplasia and the importance of cytological evaluation associated with histopathology for a correct diagnosis, prognosis and mastocytoma treatment is noted. It is emphasized that many times veterinarians face impediment related to requesting all necessary exams coming from tutors, which compromises treatment success.

Abordagem diagnóstica de mastocitoma cutâneo metastático em canino / Diagnostic approach of metastatic cutaneous mastocytoma in dog

O mastocitoma é uma das neoplasias cutâneas mais comuns que acometem cães. O diagnóstico da doença é baseado em aspectos clínicos e laboratoriais, sendo a citologia e a histopatologia os métodos de eleição. Diante disso, o objetivo deste estudo é relatar a importância da ampla abordagem diagnóstica de mastocitoma cutâneo metastático em uma fêmea canina castrada, atendida no Hospital Veterinário da Universidade Estadual do Ceará, com uma neoformação em membro compatível com mastocitoma. O estadiamento da paciente foi feito através de exames laboratoriais de hemograma completo, e citologia aspirativa de linfonodo regional e medula óssea, que evidenciaram a presença de focos de metástase; bem como do exame de ultrassom abdominal, que evidenciou alterações no parênquima hepático e linfoadenomegalia ilíaco medial direita. Diante das suspeitas, optou-se pela eutanásia da paciente, cujo corpo foi enviado para os exames de necropsia e histopatologia, os quais confirmaram o diagnóstico de mastocitoma cutâneo de alto grau, com metástase em fígado, pulmão, medula e linfonodos. Desta forma pode-se concluir que o mastocitoma cutâneo metastático é uma neoplasia de diagnóstico multifatorial, em que a realização de exames hematológicos associados às análises citológicas, histopatológicas e de imagem são indispensáveis para estabelecer o diagnóstico definitivo para que seja determinada uma melhor conduta terapêutica e prognóstico de pacientes caninos.

Mast cell tumors are one of the most common skin neoplasms that affect dogs. The diagnosis is based on clinical and laboratory aspects, with cytology and histopathology being the preferred methods. Therefore, this study aims to report the importance of the broad diagnostic approach of metastatic cutaneous mastocytoma in a castrated a female dog attended at the Veterinary Hospital of the State University of Ceará, with a neoformation in a member compatible with mast cell tumor. The patient's staging was performed through laboratory tests of complete blood count, aspiration cytology of regional lymph nodes and bone marrow, which showed the presence of focus of metastasis, as well as the abdominal ultrasound examination, which showed changes in the liver parenchymas and right medial iliac lymphadenopathy. Given the suspicions, the patient was euthanized and the body was sent for necropsy and histopathological examination, which confirmed the diagnosis of high-grade cutaneous mast cell tumor, with metastasis in the liver, lung, bone marrow, and lymph nodes. Thus, it can be is concluded that mast cell tumor is a neoplasm of multifactorial diagnosis, where hematological tests associated with cytology, histopathological, and imaging analyses are essential to establish the definitive diagnosis to determine a better therapeutic behavior and prognosis of canine patients.

Canine mast cell tumour lomustine's sensitization by tyrosine kinase inhibitors

Background: Tyrosine kinase inhibitors (TKIs) may sensitize neoplasms to conventional antineoplastic agents, however such studies are scarse in the veterinary literature and there is no in vivo study about this subject. Although the literature recommend consensual about the use of masitinib for unresectable or metastatic MCTs, the potential of tumour sensitization to chemotherapeutic agents exerted by the drug is poorly explored in veterinary medicine. The objective of this paper was to report, for the first time, the sensitization of 2 canine mast cell tumours (MCTs) to lomustine, with the use of 2 tyrosine kinase inhibitors: masitinib and toceranib. Cases: Two dogs were referred due tumour recurrence in the left pelvic limb (dog 1), and unilateral mass in the right nasal mucocutaneous region (dog 2). The first case was a 8-year-old female Pinscher, and the second case refers to a 8-year-old male mixed-breed dog. Fine needle aspiration of both lesions was performed, and the cytological analysis were compatible with high grade canine MCT. In the first case, it was started a chemotherapeutic treatment with intravenous vinblastine (2 mg/m² ), associated with prednisolone (40 mg/m2 , every 24 h for 7 days), followed by 25 mg/m2 every 24 h, for more 30 days, tramadol (4 mg/kg every 8 h, until new recommendations) and gabapentin (3 mg/kg every 12 h, until new recommendations). However, there was no objective response, and vinblastine was substituted by lomustine (60 mg/m2 every 21 days), however there was also no response after 2 doses. After masitinib importation, the same was started at 12.5 mg/kg orally every 24 h, but there was also no objective response. However, after new lomustine administration the lesion showed complete remission. The second dog initiated its treatment with toceranib, recently licensed in Brazil, at a dosage of 2.7 mg/kg every 48 h, and after 30 days, there was partial remission. However, the remaining lesion still deemed unresectable, and systemic chemotherapy with lomustine (50 mg/m2 ) was initiated along with continuous toceranib. After 3 weeks of the first chemotherapy complete remission was noted and a second dose was administered. Once the patient remained in complete clinical remission, only toceranib was maintained at the same dose. After 11 months using the toceranib, there was sign of disease recurrence and lomustine was re-initiated resulting in complete remission. Discussion: The TKIs masitinib and toceranib might be considered the first-line therapy for unresectable and/or metastatic canine MCT, but also for those cases with confirmed internal tandem duplications in the exon 11 of the c-KIT protooncogene. Masitinib appears to be more selective than others TKI, such as toceranib, imatinib, dasatinib and sunitinib, because it causes weak inhibition of BCR/ABL (breakpoint cluster region-Abelson), Fms (macrophage colony-stimulating factor receptor), Flt-3 (FMS-like tyrosine kinase-3) and VEGFR (vascular endothelial growth factor receptor), which may partially explains its increased safety and lower risk of cardiotoxicity. In the first case, the animal has been treated with lomustine associated to masitinib and showed a progression-free interval of 33 days, however, the response reported may have been lower, due previously exposition to chemotherapeutic agents, which might compromise the response to TKI. The second case, with the association of lomustine and toceranib, was followed up for 365 days, presenting only one recurrence in the final third of the follow-up, however, with subsequent new complete remission. Sensitization of canine MCT to lomustine with TKIs increases the therapeutic possibilities for this neoplasm, mainly in patients with advanced stage and high-grade tumours.

Cutaneous mast cell tumor in a captive Bush dog (Speothos venaticus): pathological and immunophenotypical aspects - case report / Mastocitoma cutâneo em um cachorro-do-mato vinagre (Speothos venaticus) de cativeiro: aspectos patológicos e imunofenotípicos - relato de caso

A senile male captive bush dog (Speothos venaticus) presented a small perianal cutaneous nodule. Histologically, there was an ulcerated round cell tumor composed of well differentiated mast cells with abundant intracytoplasmic purple Giemsa-positive granules, with a diffuse eosinophilic infiltrate. Immunohistochemistry revealed that 30% of the neoplastic cells were positive for Kit in the cytoplasm and cell membrane, and all neoplastic cells were negative for MAC and CD3. Less than 10% of the neoplastic cells were positive for Ki67. At necropsy other primary tumors were identified in this animal, including an intestinal adenoma, an adrenal cortex adenoma and a testicular interstitial cell tumor.(AU)

Um cachorro-vinagre (Speothos venaticus) apresentou um nódulo cutâneo pequeno na região perianal. Histologicamente havia neoplasia cutânea de células redondas e ulcerada, constituída por mastócitos bem diferenciados, com abundantes grânulos citoplasmáticos metacromáticos na coloração de Giemsa e infiltrado eosinofílico difuso. A imuno-histoquímica demonstrou que 30% das células neoplásicas eram positivas para a proteína Kit no citoplasma e na membrana celular. As células foram negativas para MAC e CD3. Menos de 10% das células neoplásicas foram positivas para Ki67. Durante a necropsia, foram identificados outros tumores primários, como adenoma intestinal, adenoma cortical da adrenal e tumor de células intersticiais do testículo.(AU)

Peripheral nerve sheath tumor in the upper eyelid in a dog

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)

Ampliação de margens em cão com mastocitoma cutâneo: relato de caso / Margins enlargement in dog for cutaneous mastocytoma: case report

Objetiva-se relatar a reintervenção cirúrgica para ampliação de margens em um paciente diagnosticado com mastocitoma cutâneo. Um canino, macho, Bulldog Francês, com 7 anos foi atendido com histórico de retirada de nódulo cutâneo em região abdominal há 15 dias, com diagnóstico histopatológico compatível com mastocitoma grau I e margens cirúrgicas comprometidas. Optou-se então pela realização de um segundo procedimento cirúrgico para ampliação das margens de segurança, o qual foi precedido por planejamento de 5 cm de margens cutâneas e uma camada de fáscia e um plano muscular como margem profunda, juntamente com a linfadenectomia inguinal. Durante o procedimento, foi possível a síntese sem a necessidade do uso de técnicas reconstrutivas, a partir da divulsão do subcutâneo e da utilização do padrão Walking Suture. Não houve intercorrências transoperatórias, e a formação de hematoma foi a única complicação pósoperatória observada. O material foi enviado para análise histopatológica, confirmando mastocitoma cutâneo baixo grau/grau I com margens livres, sem evidências de metástase em linfonodo. Dessa forma, não foram instituídas terapias adjuvantes, e após 320 dias pós-operatórios, o paciente apresentava-se em ótimo estado geral, sem evidências de recidiva ou metástases à distância na radiografia torácica e ultrassonografia abdominal. Conclui-se que a reintervenção cirúrgica pode ser uma alternativa para o tratamento do mastocitoma baixo grau/grau I com margens comprometidas, sendo o diagnóstico histopatológico e o planejamento cirúrgico essenciais para redução de complicações trans e pósoperatórias, aumentando as chances de sucesso e cura do paciente.

The objective is to report the surgical reintervention for enlarging margins in a patient diagnosed with cutaneous mast cell tumor. A canine, male, French Bulldog, 7 years old, was seen with a history of skin nodule removal in the abdominal region 15 days ago, with a histopathological diagnosis compatible with grade I mastocytoma and compromised surgical margins. Then, it was decided to perform a second surgical procedure to expand the safety margins, which was preceded by planning 5 cm of cutaneous margins and a layer of fascia and a muscular plane as a deep margin, in addition to inguinal lymphadenectomy. During the procedure, synthesis was possible without the use of reconstructive techniques, from the subcutaneous divulsion and the use of the Walking Suture pattern. There were no transoperative complications, and hematoma formation was the only postoperative complication observed. The material was sent for histopathological analysis, confirming low-grade cutaneous mastocytoma with free margins and no evidence of lymph node metastasis. Thus, adjuvant therapies were not instituted, and after 320 postoperative days, the patient was in excellent general condition, with no evidence of recurrence or distant metastases on chest radiography and abdominal ultrasound. It is concluded that surgical reintervention can be an alternative for the treatment of low-grade mastocytoma with compromised margins, and that histopathological diagnosis and surgical planning are essential to reduce trans and postoperative complications, increasing the chances of success and cure of the patient.

Ampliação de margens em cão com mastocitoma cutâneo: relato de caso / Margins enlargement in dog for cutaneous mastocytoma: case report

Objetiva-se relatar a reintervenção cirúrgica para ampliação de margens em um paciente diagnosticado com mastocitoma cutâneo. Um canino, macho, Bulldog Francês, com 7 anos foi atendido com histórico de retirada de nódulo cutâneo em região abdominal há 15 dias, com diagnóstico histopatológico compatível com mastocitoma grau I e margens cirúrgicas comprometidas. Optou-se então pela realização de um segundo procedimento cirúrgico para ampliação das margens de segurança, o qual foi precedido por planejamento de 5 cm de margens cutâneas e uma camada de fáscia e um plano muscular como margem profunda, juntamente com a linfadenectomia inguinal. Durante o procedimento, foi possível a síntese sem a necessidade do uso de técnicas reconstrutivas, a partir da divulsão do subcutâneo e da utilização do padrão Walking Suture. Não houve intercorrências transoperatórias, e a formação de hematoma foi a única complicação pósoperatória observada. O material foi enviado para análise histopatológica, confirmando mastocitoma cutâneo baixo grau/grau I com margens livres, sem evidências de metástase em linfonodo. Dessa forma, não foram instituídas terapias adjuvantes, e após 320 dias pós-operatórios, o paciente apresentava-se em ótimo estado geral, sem evidências de recidiva ou metástases à distância na radiografia torácica e ultrassonografia abdominal. Conclui-se que a reintervenção cirúrgica pode ser uma alternativa para o tratamento do mastocitoma baixo grau/grau I com margens comprometidas, sendo o diagnóstico histopatológico e o planejamento cirúrgico essenciais para redução de complicações trans e pósoperatórias, aumentando as chances de sucesso e cura do paciente.(AU)

The objective is to report the surgical reintervention for enlarging margins in a patient diagnosed with cutaneous mast cell tumor. A canine, male, French Bulldog, 7 years old, was seen with a history of skin nodule removal in the abdominal region 15 days ago, with a histopathological diagnosis compatible with grade I mastocytoma and compromised surgical margins. Then, it was decided to perform a second surgical procedure to expand the safety margins, which was preceded by planning 5 cm of cutaneous margins and a layer of fascia and a muscular plane as a deep margin, in addition to inguinal lymphadenectomy. During the procedure, synthesis was possible without the use of reconstructive techniques, from the subcutaneous divulsion and the use of the Walking Suture pattern. There were no transoperative complications, and hematoma formation was the only postoperative complication observed. The material was sent for histopathological analysis, confirming low-grade cutaneous mastocytoma with free margins and no evidence of lymph node metastasis. Thus, adjuvant therapies were not instituted, and after 320 postoperative days, the patient was in excellent general condition, with no evidence of recurrence or distant metastases on chest radiography and abdominal ultrasound. It is concluded that surgical reintervention can be an alternative for the treatment of low-grade mastocytoma with compromised margins, and that histopathological diagnosis and surgical planning are essential to reduce trans and postoperative complications, increasing the chances of success and cure of the patient.(AU)

Comparison of two different vinblastine dosages for treatment of cutaneous mast cell tumor in dogs

Background: Mast cell tumors (MCT) are among the most common malignant cutaneous neoplasm in dogs with variable biologic behavior and remain a therapeutic challenge in high-grade cases. Surgery remains the primary treatment for canine MCT; however, chemotherapy and radiation therapy are commonly used to treat aggressive cases. The combination of vinblastine (VBL) at a dose of 2 mg/m² and prednisone is the classically described protocol for MCT treatment. Studies have shown the safety of higher VBL doses for dogs with MCT, but there is a lack of information regarding dose intensity and outcome as a goal after chemotherapy. This study aimed to evaluate the impact of a higher dose of VBL on MCT treatment outcome. Materials, Methods & Results: This was an observational and comparative study conducted in two different Veterinary Teaching Hospitals. Client-owned dogs with histopathological diagnosis of grade II or III MCT were selected and underwent at least four chemotherapy sessions with VBL and prednisone. The experimental group (EG) consisted of 18 dogs that received a dose of 3 mg/m² VBL treated in one institution. The control group (CG) included 31 dogs that received a dose of 2 mg/m² VBL treated at the other institution. All dogs treated in both groups had a clinical and complete blood count (CBC) evaluation performed previous the start of chemotherapy (T0) and before each weekly treatment (T1, T2, T3, and T4). After treatment, dogs in both groups were followed-up for the recurrence rate and overall survival time after diagnosis. There was no significant difference in clinical variables between EG and CG. During treatment, dogs of EG showed a significant reduction in erythrocyte, hemoglobin, and hematocrit values between T0 and T1, T2, T3, and T4 (P < 0.001). Comparatively, the CG showed significant reduction in hemoglobin (P = 0.02) and total leucocytes (P = 0.001) values in the same period. Despite these findings, these hematological...

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)

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)

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...

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)

Use of different fixation times and application of two immunohistochemical methods for detection of KIT and Ki67 proteins in canine cutaneous mast cell tumors / Utilização de diferentes tempos de fixação e métodos imuno-histoquímicos na detecção das proteínas KIT e Ki67 em mastocitomas cutâneos caninos

Due to the high prevalence of mast cell tumors (MCTs) in the diagnostic routine, several factors, especially prognostic, have been sought to determine the biological behavior of these neoplasms. Immunohistochemistry (IHC) is one of the main tools utilized to biologically differentiate more aggressive tumors from less aggressive ones. However, some immunostainings are influenced by formalin fixation, interfering with the results. This is both a retrospective and prospective study of MCTs diagnosed in laboratory routine. A total of 25 samples, without knowledge about fixation time, were analyzed in the retrospective study, whereas 12 samples, with known fixation times, were assessed in the prospective study. Two histologic grading systems (Patnaik and Kiupel), special staining of toluidine blue, and IHC for KIT and Ki67 proteins were applied in both studies. Additionally, two amplification systems (biotinylated and non-biotinylated) for Ki67 protein and counting of the argyrophilic nucleolar organizing regions (AgNOR method) were tested in the prospective study. In the retrospective study, greater agreement between the evaluating pathologists was observed when the Kiupel system was used. IHC staining for KIT protein was effective in both studies, regardless of fixation time. IHC staining for Ki67 protein was highly sensitive to formaldehyde, and staining failure was observed in 56% of the cases in the retrospective study. In the prospective study, samples fixed for longer than 24 hours showed a reduction in the number of stained cells (altering the determination of the cell growth fraction) or showed absence of IHC staining in both amplification systems. The use of the AgNOR method to evaluate the rate of cell proliferation may be an alternative when the fixation time of the neoplasm is unknown or longer than 24 hours.(AU)

Devido a alta prevalência dos mastocitomas cutâneos caninos (MCCs) na rotina diagnóstica, vários fatores, especialmente fatores prognósticos, têm sido buscados para auxiliar na determinação do comportamento biológico desse neoplasma. A imuno-histoquímica é uma das principais ferramentas empregadas para diferenciar tumores biologicamente mais agressivos de tumores menos agressivos. Entretanto, algumas imunomarcações sofrem influência pela fixação em formol, interferindo nos resultados. Este estudo compreendeu avaliar através de uma etapa retrospectiva e uma etapa prospectiva casos de MCCs diagnosticados na rotina laboratorial. Um total de 25 amostras, sem conhecimento do tempo de fixação, foi analisado no estudo retrospectivo e 12 amostras, com tempos de fixação conhecidos, no estudo prospectivo. Foram aplicados nos dois estudos, dois sistemas de graduação histológica (Patnaik e Kiupel), a coloração especial de azul de toluidina e a imuno-histoquímica para as proteínas KIT e Ki67. Adicionalmente, no estudo prospectivo, foram testados dois sistemas de amplificação (biotinilado e não biotinilado) para a proteína Ki67 e a técnica de AgNOR (contagem das regiões organizadoras nucleolares argirofílicas). Na etapa retrospectiva, observou-se uma maior concordância entre os patologistas avaliadores quando o sistema Kiupel foi utilizado. A imunomarcação para KIT se manteve eficaz em ambos os estudos, independentemente do tempo de fixação. A imunomarcação para o Ki67 mostrou-se altamente sensível ao tempo de fixação em formol, sendo observada falha na imunomarcação em 56% dos casos do estudo retrospectivo. No estudo prospectivo, constatou-se que amostras fixadas por mais de 24 horas em formol apresentaram redução na quantidade de células imunomarcadas (alterando a determinação da fração de crescimento celular) ou apresentaram ausência de imunomarcação em ambos os sistemas de amplificação. A utilização do método AgNOR, para avaliar a taxa de proliferação celular, pode ser uma alternativa quando o tempo de fixação do neoplasma for desconhecido ou superior a 24 horas.(AU)

Use of different fixation times and application of two immunohistochemical methods for detection of KIT and Ki67 proteins in canine cutaneous mast cell tumors / Utilização de diferentes tempos de fixação e métodos imuno-histoquímicos na detecção das proteínas KIT e Ki67 em mastocitomas cutâneos caninos

Due to the high prevalence of mast cell tumors (MCTs) in the diagnostic routine, several factors, especially prognostic, have been sought to determine the biological behavior of these neoplasms. Immunohistochemistry (IHC) is one of the main tools utilized to biologically differentiate more aggressive tumors from less aggressive ones. However, some immunostainings are influenced by formalin fixation, interfering with the results. This is both a retrospective and prospective study of MCTs diagnosed in laboratory routine. A total of 25 samples, without knowledge about fixation time, were analyzed in the retrospective study, whereas 12 samples, with known fixation times, were assessed in the prospective study. Two histologic grading systems (Patnaik and Kiupel), special staining of toluidine blue, and IHC for KIT and Ki67 proteins were applied in both studies. Additionally, two amplification systems (biotinylated and non-biotinylated) for Ki67 protein and counting of the argyrophilic nucleolar organizing regions (AgNOR method) were tested in the prospective study. In the retrospective study, greater agreement between the evaluating pathologists was observed when the Kiupel system was used. IHC staining for KIT protein was effective in both studies, regardless of fixation time. IHC staining for Ki67 protein was highly sensitive to formaldehyde, and staining failure was observed in 56% of the cases in the retrospective study. In the prospective study, samples fixed for longer than 24 hours showed a reduction in the number of stained cells (altering the determination of the cell growth fraction) or showed absence of IHC staining in both amplification systems. The use of the AgNOR method to evaluate the rate of cell proliferation may be an alternative when the fixation time of the neoplasm is unknown or longer than 24 hours.(AU)

Devido a alta prevalência dos mastocitomas cutâneos caninos (MCCs) na rotina diagnóstica, vários fatores, especialmente fatores prognósticos, têm sido buscados para auxiliar na determinação do comportamento biológico desse neoplasma. A imuno-histoquímica é uma das principais ferramentas empregadas para diferenciar tumores biologicamente mais agressivos de tumores menos agressivos. Entretanto, algumas imunomarcações sofrem influência pela fixação em formol, interferindo nos resultados. Este estudo compreendeu avaliar através de uma etapa retrospectiva e uma etapa prospectiva casos de MCCs diagnosticados na rotina laboratorial. Um total de 25 amostras, sem conhecimento do tempo de fixação, foi analisado no estudo retrospectivo e 12 amostras, com tempos de fixação conhecidos, no estudo prospectivo. Foram aplicados nos dois estudos, dois sistemas de graduação histológica (Patnaik e Kiupel), a coloração especial de azul de toluidina e a imuno-histoquímica para as proteínas KIT e Ki67. Adicionalmente, no estudo prospectivo, foram testados dois sistemas de amplificação (biotinilado e não biotinilado) para a proteína Ki67 e a técnica de AgNOR (contagem das regiões organizadoras nucleolares argirofílicas). Na etapa retrospectiva, observou-se uma maior concordância entre os patologistas avaliadores quando o sistema Kiupel foi utilizado. A imunomarcação para KIT se manteve eficaz em ambos os estudos, independentemente do tempo de fixação. A imunomarcação para o Ki67 mostrou-se altamente sensível ao tempo de fixação em formol, sendo observada falha na imunomarcação em 56% dos casos do estudo retrospectivo. No estudo prospectivo, constatou-se que amostras fixadas por mais de 24 horas em formol apresentaram redução na quantidade de células imunomarcadas (alterando a determinação da fração de crescimento celular) ou apresentaram ausência de imunomarcação em ambos os sistemas de amplificação. A utilização do método AgNOR, para avaliar a taxa de proliferação celular, pode ser uma alternativa quando o tempo de fixação do neoplasma for desconhecido ou superior a 24 horas.(AU)

H-Plastia com flap de avanço para reconstrução de região nasal após exérese de nódulo em cão / H-Plasty with advancement flap for reconstruction of nasal region after nodule excision in a dog

O uso da cirurgia reconstrutiva no campo da Medicina Veterinária vem crescendo cada vez mais, principalmente quando associado a ressecções tumorais. Este relatório descreve a reconstrução cirúrgica com o uso de retalhos de avanço nasais pela técnica da plastia H, após ressecção tumoral sugestiva de mastocitoma em um cão. O animal foi tratado no Hospital Veterinário do Departamento de Medicina Veterinária da Universidade Federal Rural de Pernambuco, onde foi realizada a avaliação física e solicitados exames complementares para posterior encaminhamento à cirurgia. O tutor relatou que o nódulo começou a crescer 15 dias antes do procedimento. A massa neoplásica estava localizada na porção dorsal do plano nasal, com diagnóstico citológico sugestivo de mastocitoma.

The use of reconstructive surgery in the field of Veterinary Medicine has been growing increasingly, specially when associated with tumor resections. This report describes the surgical reconstruction with the use of advancement flaps in the nasal using the H-plasty technique, after tumor resection suggestive of mastocytoma in a dog. The animal was treated at the Veterinary Hospital of the Department of Veterinary Medicine of the Federal Rural University of Pernambuco, where the physical evaluation was made and complementary exams were requested for subsequent referral to surgery. The tutor reported that the nodule started growing 15 days before the procedure. The neoplastic mass was located in the dorsal portion of the nasal plane, with a cytological diagnosis suggestive of mastocytoma.

H-plastia com flap de avanço para reconstrução de região nasal após exérese de nódulo em cão / H-plasty with advancement flap for reconstruction of nasal region after nodule excision in a dog

O uso da cirurgia reconstrutiva no campo da Medicina Veterinária vem crescendo cada vez mais, principalmente quando associado a ressecções tumorais. Este relatório descreve a reconstrução cirúrgica com o uso de retalhos de avanço nasais pela técnica da plastia H, após ressecção tumoral sugestiva de mastocitoma em um cão. O animal foi tratado no Hospital Veterinário do Departamento de Medicina Veterinária da Universidade Federal Rural de Pernambuco, onde foi realizada a avaliação física e solicitados exames complementares para posterior encaminhamento à cirurgia. O tutor relatou que o nódulo começou a crescer 15 dias antes do procedimento. A massa neoplásica estava localizada na porção dorsal do plano nasal, com diagnóstico citológico sugestivo de mastocitoma.(AU)

The use of reconstructive surgery in the field of Veterinary Medicine has been growing increasingly, specially when associated with tumor resections. This report describes the surgical reconstruction with the use of advancement flaps in the nasal using the H-plasty technique, after tumor resection suggestive of mastocytoma in a dog. The animal was treated at the Veterinary Hospital of the Department of Veterinary Medicine of the Federal Rural University of Pernambuco, where the physical evaluation was made and complementary exams were requested for subsequent referral to surgery. The tutor reported that the nodule started growing 15 days before the procedure. The neoplastic mass was located in the dorsal portion of the nasal plane, with a cytological diagnosis suggestive of mastocytoma.(AU)