Is there a relationship between the expression of β-catenin and Ki-67 in canine melanocytic neoplasms? Existe relação entre a expressão de β-catenina e Ki-67 em neoplasias melanocíticas caninas?

An immunohistochemical evaluation of 26 cutaneous and oral benign and malignant canine melanocytic neoplasms was performed to identify a possible relationship between the expression of the β-catenin molecule with cell proliferation using Ki-67 expression. This molecule is a component of the Wnt/β-catenin signalling pathway, which causes a cascade of intracellular events that activate transduction genes and nuclear transcription. The microscopic evaluation was performed considering the β-catenin labelling site (cytoplasmic, nuclear or mixed). The mitotic index was evaluated by the expression of Ki-67 in 10 high power fields (HPF) (400x). Statistically significant difference was neither detected between the β-catenin labelling sites and the various neoplasms, nor a correlation between the β-catenin molecule and the cell proliferation marker Ki-67 in the oral or cutaneous, benign or malignant neoplasms. Our study brings interesting findings and points to future research on this topic, especially with established variables in the clinical, pathological and immunohistochemical fields

Feline Lymphoplasmacytic Gingivostomatitis: Clinical and Anatomopathological Aspects

Background: Feline lymphoplasmacytic gingivostomatitis (FLPG) is an idiopathic, multifactorial and highly challenging condition, since the results of the available treatments are partial and transitory. A set of lesions triggered by inflammatory reaction is observed, sometimes with ulcerations in the oral mucosa, leading to algia and discomfort. Histopathological examination figures as the definitive diagnostic tool, presenting distinct cellular elements. The present study aims to report three cases of FLPG, firstly addressing the anatomopathological findings, as well as the therapeutic approach used and the results obtained in each case.Cases: Case 1- Occurred in a feline Siamese male 15-year-old, weighing 3.8 kg, which was admitted at a local clinic, under the complaint of prostration, dysphagia, and weight loss, signs that were noticed approximately 5 days before. Clinical evaluation revealed multiple proliferative and ulcerative lesions, extending until the isthmus of the fauces, erythematous areas around the teeth and multifocal gingival reabsorption. Once the clinical signs and lesions were observed, samples were collected for histopathological examination and sent to the Laboratory of Animal Pathology (LAP) of Faculty of Agronomy and Veterinary Medicine of the University of Passo Fundo (FAVM-UPF). Histologically, both fragments presented lymphoplasmacytic infiltration, with large and intensely eosinophilic cytoplasm, often with granular aspect, central to lateralized hyperchromatic nuclei, located predominantly in lamina propria and mucosa, as well as a discrete Mott cell infiltrate. It was also observed the presence of diffuse suppurative chronic inflammatory infiltrate, predominantly in lamina propria and mucosa, as well as foci of edema and hemorrhage, in addition to loss of tissue architecture establishing the definitive diagnosis of FLPG. The tutor went to another veterinarian for a second opinion, but the patient died within four months. Case 2- Occurred in a no defined-breed male feline 7-year-old, weighing 3.9 kg, on complaint of hyporexia, inappetence, progressive thinning and greasy-looking fur. The tutor reported that the patient showed an increasing disinterest for offered feed, for approximately three weeks, but in recent days, consumption had declined dramatically. Clinical evaluation showed the same pattern of lesions in case 1, but with higher intensity, especially in the fauces area, as well as multifocal periodontal lesion and gingival retraction areas in several teeth. After the clinical signs and lesions were observed, samples were collected for histopathological examination and sent to the LAP of the FAVM-UPF, having the same diagnosis of case 1. The patient was submitted to a complete teeth extraction and, up to date, is asymptomatic, with a positive evolution. Case 3- Occurred in a no defined-breed female feline 6-year-old, weighing 4.1 kg, showing bleeding gums, reluctance to eat and mild halitosis, signs noticed around two weeks before. The patient was submitted to clinical evaluation, with lesions that consisted of erythematous areas, more evident in molar teeth, as well as ulcerated foci of the oral mucosa. Samples were collected for histopathological examination and sent to the LAP of the FAVM-UPF, with the same diagnosis as previous cases. The therapeutic approach used consisted of immunodulation and immunosuppression, using cyclosporin and prednisolone, respectively. Up to present, the patient shows control on severity of lesions, maintaining a good life quality. Discussion: The present study observed that clinical and anatomopathological findings corroborate with those cited in the literature, with special emphasis on the presence of Mott cells as well as the marked lymphoplasmacytic infiltrate, common in all three cases. The results of chosen treatments showed variation in results, even with the individualization of the therapeutic approach in the three cases

Pylorectomy and Gastroduodenostomy (Billroth I Procedure) for Obstructive Antrum Pyloric Leiomyoma in a Bitch

Background: Gastric neoplasms are uncommon in dogs, especially those affecting smooth muscle layers. Leiomyoma is a smooth muscle benign neoplasm, which requires surgical resection. Pylorectomy and gastroduodenostomy (Billroth I procedure) is the most indicated technique in cases not affecting the biliary and pancreatic tracts. Thus, the purpose of this study was to report a successful case of Billroth I procedure in a bitch presenting antrum pyloric obstructive leiomyoma. Case: A 12-year-old, non-spayed, Cocker Spaniel bitch was admitted presenting depression, hyporexia, postprandial vomiting and sparse episodes of hematemesis, for 30 days. Clinical suspicion on obstructive gastric outflow disease was established. Bloodwork (complete blood count, BUN, albumin, ALP and ALT), abdominal ultrasound and thoracic radiographs were assessed. The patient undergone upper gastrointestinal endoscopy. On endoscopic evaluation, small hemorrhagic mucosa ulcers were visualized on the gastric body, antrum and pylorus. Moreover, a sessile, ulcerated, round-shape and infiltrated antral-pyloric mass was seen. The mass was 1.5-2.0 cm in diameter and apparently involved the smooth muscle layer, causing severe pyloric obstruction. However, endoscopic evaluation of the duodenum was possible. Several biopsy samples were taken from the neoplasm and sent for histopathologic assessment. The result was not conclusive due to low quality samples. The patient had progressive worsening of obstruction episodes and required surgery. A wide-margin pylorectomy and gastroduodenostomy (Billroth I procedure) was carried out. The retrieved specimen was sent to histopathological and immunohistochemistry (IHC) assessment. Positive staining for actin and desmin confirmed smooth muscle origin of the mass and histopathological assessment confirmed leiomyoma. The patient underwent regular periodic postoperative assessments, revealing progressive clinical improvement and normal weight gain. Control upper gastrointestinal endoscopy was performed. Gastric ulcers were completely healed and gastroduodenal anastomosis was functional. The anastomotic scar tissue was sampled and revealed chronic and normal healing process. Complete healing was confirmed and the patient was discharged. Discussion: Gastric neoplasms are not common in dogs. However, severe obstruction of gastric outflow is a potential risk for complications in those cases. Upper gastrointestinal endoscopic assessment is important not only for diagnosis, but also for surgery decision making. In the current study, gastroscopy provided accurate preoperative evaluation of severity of pyloric obstruction and diagnosis of secondary gastric ulcers. Direct visualization of lesions and multiple biopsy sampling were performed. The presence of neoplasms over 2-cm in diameter indicates need for complete laparoscopic or conventional surgical resection. In this case report, open resection was carried out due to prohibitive cost of laparoscopic approach, mass dimensions and probable involvement of deeper tissue layers. In conclusion, pylorectomy and gastroduodenostomy (Billroth I procedure) was curative and provided good prognosis following resection of an antrum pyloric obstructive leiomyoma. Endoscopy was critical for both diagnosis and decision-making towards surgery for gastric outflow obstruction due to an antrum pyloric neoplasm. Histopathological and immunohistochemistry assessment confirmed neoplasm type and assured oncological safety of resection with wide margins. Keywords: gastric neoplasms, smooth muscle tumor, endoscopy, dog

Immunophenotypic characterization of lymphocytic infiltration in canine melanocytic tumors / Caracterização imunofenotípica da infiltração linfocítica em tumores melanocíticos caninos

Melanocytic tumors correspond to approximately for 4 to 7% of tumors in dogs and up to 7% of malignant tumours. Melanomas generally exhibit aggressive biological behavior. In humans, abundant tumor-infiltrating lymphocytes (TIL) can be considered a good prognostic factor. Research on TIL in canine melanomas is scarce, and to date, there are no studies to verify its association with established prognostic factors. Our study aimed to evaluate the lymphocyte population in canine melanocytic tumors using immunohistochemical markers, and to relate this to pre-established clinicopathological prognostic variables and cell proliferation index (Ki-67). An exploratory cross-sectional study was conducted with 21 cases in 19 dogs, of which 71.5% were melanotic melanomas, 19% were melanocytomas and 9.5% were amelanotic melanomas. Ki-67 expression was elevated in amelanotic melanomas, indicating aggressive tumor behavior. We detected lymphocytes T and B through CD3 and CD20 markers, respectively, and found that 86.7% of the melanotic melanomas were positive for CD3, whereas 73.3% were negative for CD20. TIL showed a strong association with malignant tumors, as well as a correlation with other pre-established prognostic factors, such as necrosis, ulceration, and nuclear atypia. TIL need to be further investigated to verify its inclusion as a prognostic factor for canine melanomas

Iatrogenic Postvaccinal Injection Site Granulomas in Cattle

Background: The Brazilian government has established disease eradication and control programs to protect livestock from pathogens that affect animal health and compromise animal protein production and food safety and quality. Vaccination campaigns against foot-and-mouth disease and other infectious diseases in cattle except brucellosis can be carried out bynon-veterinarian employees. However, vaccination errors can result in the formation of granulomas at injection sites that can affect animal welfare and production. The present study aimed to report two cases of granulomas at injection sites due to the inadvertent administration of vaccines containing saponins and mineral oil as adjuvants.Cases: Case 1. The history was that a 2-year-old Devon steer was down for 7 days and was vaccinated 20 days ago with a vaccine containing saponins and mineral oil as adjuvants. Case 2. A 7-month-old Holstein heifer was examinated due to a 40-day history of ataxia, forelimb paresis progressing to tetraparesis, and vaccination with a vaccine containing saponins and mineral oil as adjuvants 60 days ago. These two animals were admitted in the Veterinary Hospital from the University of Passo Fundo (UPF) with a clinical history of incoordination and permanent decubitus after vaccination. The disease had a similar clinical course in both animals. Clinical signs included the presence of a palpable cervical mass at the site of vaccination, forelimb paresis that progressed to tetraparesis, and decubitus scars. Treatment included intravenousadministration of anti-inflammatory steroids, antibiotic therapy, daily cleansing of the pressure sores, all four limbs were massaged, animals underwent several physiotherapy sessions, slings were used to mantain recumbent patients in a standing position and supportive therapy consisted of fluid therapy and oral supplementation. Animals remained hospitalizedfor approximately 40 days. Pacients experienced temporary improvement during treatment, and would walk with an uncoordinated gait. The clinical picture worsened after treatment was discontinued, necessitating euthanasia. At necropsy, gross lesions were similar in both animals. In case 1, the trapezius was firm and pale and had multiple granulomas whichextended into the cervical vertebral column at C3-C4 and invaded the spinal canal compressing the spinal cord. In case 2, there was extensive damage to the trapezius by granulomatous inflammation; numerous nodular granulomas exuded milky contents. These lesions extended deep into the muscle fibers and infiltrated the vertebral column at C5-C6, with involvement of the medullary canal and spinal cord compression. Microscopically there was severe, diffuse pyogranulomatous myositis. Each pyogranuloma had a central clear space. Nodal architecture was effaced by these inflammatory nodules.Discussion: Some drugs and vaccines contain irritating adjuvants and induce granuloma formation at the inoculation site. In both cattle, vaccines were injected intramuscularly in the cranial third of the neck in close proximity to the cervical vertebrae and surrounding tissues. These vaccines possibly induced an exuberant inflammatory reaction at the inoculationsite. An exacerbated inflammatory response following the administration of adjuvanted vaccines by improperly trained personnel caused substantial tissue damage at the injection site. Severe, locally extensive lesions were found at necropsy affecting adjacent structures including skeletal muscles and spinal cord. The clinical signs of ataxia and forelimb paresis thatprogressed to tetraparesis were due to the marked pyogranulomatous inflammation in C3-C4 in case 1 and in C5-C6 in case 2. The present study reinforces the importance of good farming practices and properly trained personnel working at farms.Keywords: bovine, vaccine, infection site, granuloma, iatrogenic

Linfoma cutâneo em equino Quarto de Milha

Background: Lymphoma, although rare, is the most common hematopoietic neoplasia in horses. The overall incidence of lymphoma is between 1.3-2.8% of all equine neoplasia and it has a prevalence of 0.002-0.5% in the equine population. Lymphoma can be classified as multicentric, alimentary, mediastinal, cutaneous and solitary. The cutaneous is the rarest form and it usually presents with multifocal skin lesions, with no other clinical signs. The diagnoses is accomplished by histopathological examination of a biopsy or cytological examination of a fine needle aspirate. The aim of the current study is to report a case of the rarest form of equine lymphoma, the cutaneous.Case: An 8-year-old equine female, Quarter Mile, was evaluated due to volume’s increase and subcutaneous nodules disseminated along the body. These lesions developed gradually during 2 years. The mare was used for ridding, it was kept in the field with 10 other equines and was the only one affected. The mare was vaccinated for influenza and was negative for glanders and equine infectious anemia. During clinical exam, all vital parameters were within limits and body condition score was classified as 6 (Henneke Chart). It was observed bilateral nasal secretion and depigmentation in ocular and vulvar mucous. It was observed multiple delimited areas with size ranging from few cm up to 7 cm, hard, mobile, painless, located in the subcutaneous and disseminated in the body (including head, neck, thorax, limbs and perineum). Red blood cell, leucocytes, fibrinogen, total plasmatic protein were within normal limits. Due to clinical signs and the potential risk of a zoonosis, the glanders test was repeated (complement fixation test) and the result was negative. Differential diagnoses also included insect hypersensitive, which was discarded since the female did not presented pruritus nor alopecia, lesions gradually increased in size and no seasonality was observed. It was performed excisional biopsy for tissue culture, which revealed no growth of aerobic mesophile bacteria. Histopathological evaluation revealed rounded cell proliferation similar to lymphocytes situated in the deep derma and subcutaneous. After evaluation of history, clinical exam and complementary exams the mare was diagnosed with cutaneous lymphoma. The owner was instructed that there was no available specific treatment with good efficacy and viable for equines at this stage. Besides, it is important to evaluated the mare constantly due the possibility of future lesions in organs or intern lymph nodes.Discussion: Cutaneous lymphoma is an uncommon disease, especially in horses, that can present with variable clinical signs, immunosuppression, rapid systemic disease progression or none at all. In the present case report, during clinical examination lesions were observed in areas of lymphatic drainage. Identification of neoplastic lymphocytes during cytological examination or histopathological evaluation of biopsy tissue can confirm the presence of lymphoma, as performed in the present case. Treatment is palliative and occasionally results in complete cure, mainly in equine with single lesions. The mare had cutaneous lymphoma disseminated all long the body and no clinical signs that could suggest gastrointestinal neoplastic lesions, even though the owner was advised that this animal should be monitored regularly in the future, specially due the possibility of metastatic lesions in any other organ. In equine, lymphoma has low incidence and the cutaneous form is the rarest one. Clinical signs are typically non specific and develop insidiously, so it is important to perform complementary exams for accurate diagnoses and for differential diagnoses of tegumental and infectious diseases

Poisoning by Senecio brasiliensis in Horses in Northern Rio Grande do Sul

Background: In various regions of Brazil, horses and cattle are considered the most susceptible animals to plant poisoning. The plants of the genus Senecio are the most important in Rio Grande do Sul because they have the active principle known as the pyrrolizidine alkaloid. Its diagnosis is made through epidemiology, clinical signs and histopathological analysis, either of the tissues obtained by biopsy or necropsy. The objective of this study was to report and characterize the epidemiological, clinical and anatomopathological findings of three cases of natural poisoning by Senecio brasiliensis in horses assisted at the Hospital Veterinário (HV) of the Universidade de Passo Fundo (UPF).Cases: Three traction horses, two males and one female, were admitted at the HV-UPF for clinical care. The animals were presenting anorexia, weight loss, dysmetria, proprioceptive deficit and signs suggestive of colic. The epidemiological study revealed that the sites where these animals were located were infested by Senecio brasiliensis. The support therapy used for equine colic in all three cases was unsuccessful. One of the animals died and the other two were euthanized, all three of them being reffered for necropsy. The post-mortem findings were mainly found in the liver, which showed accentuation of the lobular pattern and the appearance of nutmeg. During necropsy, fragments of organs from thoracic and abdominal cavities and central nervous system were collected and fixed in 10% buffered formalin. Subsequently, the samples were processed chemically, submitted to cuts of five micrometers of thickness and stained with hematoxylin and eosin for microscopic analysis. Microscopically, the liver of all three horses presented megalocytosis, fibrosis and bile ducts hyperplasia. In the central nervous system, spongiosis and the presence of Alzheimer type II astrocytes were observed. Thus, through the association of information, the diagnosis of poisoning by Senecio brasiliensis was achieved.Discussion: The diagnosis of natural poisoning by Senecio brasiliensis was obtained through the epidemiological survey that showed S. brasiliensis in pastures where all three horses were allocated.  Cases of intoxication by S. brasieliensis in cattle are more frequent than in equines, although both species are considered the most susceptible. In horses, the main clinical manifestations observed include neurological disorders, apathy, anorexia, dysphagia, weight loss, subcutaneous edema and icterus. The clinical signs presented by the equines suggested initial signs of colic syndrome, although anorexia, weight loss, dysmetria and proprioceptive deficit are commonly observed in pyrrolizidine alkaloid poisoning in the liver, both in cattle and horses. The pyrrolizidine alkaloids present in the genus Senecio that become toxic when biotransformed in the liver into a pyrrholic form highly reactive that inhibits cell mitosis and leads to the onset of megalocytosis, cell death and liver fibrosis. The necropsy findings and histopathology were characteristic of poisoning in equines, since the predominant macroscopic lesions in the liver were hepatomegaly and accentuation of lobular pattern, whereas microscopically, there was a predominance of hepatic fibrosis, megalocytosis, spongiosis and the incidence of Alzheimer's type II astrocytes in the brain. These lesions are observed both in natural and in experimental cases of poisoning in horses. Thus, through the ante-mortem and complete post-mortem evaluation of the three equines, it was possible to establish the occurrence of natural poisoning by Senecio brasiliensis in Northern Rio Grande do Sul, as well as to characterize the epidemiological, clinical and anatomopathological findings of poisoning in this species

Testicular Teratoma in a Unilateral Right-Sided Abdominal Cryptorchid Horse

Background: Cryptorchidism is characterized by the incomplete descent of one or both testicles to the scrotum, being a hereditary alteration and frequently an unilateral condition. Besides the sexual and aggressive behaviour, the retained testicle is commonly located in abdominal cavity, being considered a risk factor for neoplasm development. The most common testicular neoplasm reported in mammalian species are Sertoli cell tumors, Leydig cell tumors, seminomas and teratomas. A presumptive diagnosis of testicular tumor can be achieved by ultrasonography, although the definitive diagnosis is obtained only by histopathology. In this report, we are presenting a of testicular teratoma in an unilateral abdominal cryptorchid horse. Case: A stallion, American Quarter Horse, 3 year-old, was attended and presented right testicle retained and a left testicle in the scrotum. Transrectal palpation was used to identify a round and firm structure, presumably the right testicle, lateral to the urinary bladder and located in the right side of the abdomen.  Further, a transrectal ultrasound examination showed a complex, round mass with irregular edges containing both cystic and solid structures, hypoechoic fluid-filled cavities separated by linear hyperechoic septa. After a clinical examination, the animal was diagnosed with cryptorchidism and was submitted to orchiectomy and cryptorchidectomy by inguinal approach. Surgery was performed under general anesthesia and postoperative care included cold shower, anti-inflammatory and antibiotic therapy. Testicles were surgically removed and further sent for histopathological examination. The visual appearance of the right undescended testicle showed multiple round, cystic, and solid structures on outer surface, while the left descended testicle was apparently normal. The macroscopic evaluation showed that the affected testicle consisted of a firm to soft solid mass with multiple fluid-filled cystic areas. Microscopically, the testicular architecture was replaced by cysts, fibrous tissue, adipose tissue, glandular structures, and foci of calcification. The histology revealed that the retained testicle had a testicular teratoma. Discussion: Reproductive disorders are common in horses and represent a significant part of the equine practitioner routine. Equine cryptorchidism is the most common non-lethal developmental defect of stallions; Surgery is the best treatment, since this alteration is hereditary. Teratomas have been reported more often in cryptorchid testicles, being usually just diagnosed as an incidental finding during surgical procedure. Under field conditions, usually the testicles are not sent for histopathological evaluation and this fact can contribute to underdiagnoses. Ultrasonography allows clinicians to determine testis location as well as morphological changes in the testes, as well as to elaborate a presumptive diagnose of testicular neoplasm. Histopathology is the best exam to achieve definitive diagnoses in the presence of testicular alterations. In our report, diagnosis of testicular neoplasia was not made before surgery and testicular mass was an incidental finding during the pre-surgical examination. Before testicular enlargement or presence of testicular mass, neoplasia should be included in the differential diagnosis. In conclusion, although rare, teratoma should be included in differential diagnoses of retained testicles, especially those with morphological alterations

Anatomopathological and immunohistochemical characterization of a case of granulomatous meningoencephalitis in a bovine with systemic tuberculosis / Caracterização anatomopatológica e imuno-histoquímica de um caso de meningite granulomatosa em bovino com tuberculose sistêmica

A two-year-old male bovine of Aberdeen Angus breed with anorexia, weight loss, and apathy was reported for necropsy, being diagnosed with systemic tuberculosis and tuberculoid meningitis lesions. Bovine tuberculosis was observed and confirmed through the necropsy of granulomatous lesions, mainly in the lungs and regional lymph nodes; specific staining for alcohol-acid resistant bacilli and immunohistochemistry were also performed. It should be noted that bovine tuberculosis is a zoonotic disease, with mandatory notification, caused by Mycobacterium bovis. In most cases, it has nonspecific clinical symptoms, such as respiratory signs, weight loss, and lymphadenopathy. In rare cases, alterations in the central nervous system occur. Therefore, this study aimed to report a case of granulomatous meningitis in a bovine with systemic tuberculosis through the characterization of its anatomicopathological and immunohistochemical aspects

Osteoblastic Nasal Osteosarcoma in a Wagyu Bovine

Background: Osteosarcoma is a malignant mesenchymal tumor with a wide variety of histological patterns. It is the primary bone neoplasia diagnosed in most domestic animal clinic, but rare in farm animals. The tumor develops both the appendicular skeleton as the axial skeleton, the latter being less affected. Generally it has a fast, painful and infiltrative grow, being observed metastasis. This study aims to report a case of metastatic osteoblastic osteosarcoma in the nasal bone of a bovine, diagnosed at the Animal Pathology Laboratory at the University of Passo Fundo (UPF), featuring its pathological and immunohistochemical aspects.Case: A 5 year old Wagyu female beef cattle, was treated at the Veterinary Hospital of the University of Passo Fundo. The animal had swelling in the left nasal plan, dyspnoea and anorexia. It was held cytology and biopsy which revealed malignant mesenchymal neoplasm compatible with osteosarcoma. The clinical picture has worsened and the animal died. At necropsy, the left nasal plane, had ulcerated tumor mass measuring 15x12.5x7.5 cm, hard and firm consistency with whitish color that seeped up to the turbinates and sinuses. In the lung, there were numerous nodules of tumor appearance, adhered to the parietal pleura, similar to bone tissue. In the histopathological analysis, proliferation of neoplastic cells located in the deep dermis was observed, cell thick, well-defined and infiltrative, arranged in bundles, loosely grouped with rounded shape, sometimes oval, with distinct boundaries. There were areas with formation of osteoid matrix calcification and tumor necrosis. It was observed lung and regional lymph nodes metastasis. Tissue samples were subjected to immunohistochemistry (IHC), was performed using the polymer method with horseradish peroxidase (HRP), with positive control, using a panel of antibodies. Neoplastic cells were immunoreactive for vimentin and negative for other antibodies. Thus, confirmed the case of mesenchymal origin and bone tumor.Discussion: Osteosarcoma developing in the axial skeleton, more precisely in the nasal bone, in animals of this age group, is not found frequently in the literature. However, when they occur, they have unilateral injury, remarkable facial deformities, dyspnea and infiltration of adjacent tissues. During necropsy there was observed a mass of hard consistency suggesting bone tissue in the nasal plane, there was also observed whitish spots on the lung and lymph nodes. Through microscopic analysis was obtained the classification of osteoblastic osteosarcoma. Being a malignant tumor it has a fast and infiltrative growth, there was visualized metastasis in lung and mediastinal lymph nodes. The samples submitted to immunohistochemistry were positive for vimentin and negative for other antibodies. No treatment with chemotherapy, radiation therapy or surgical intervention to remove the tumor was possible to be performed. Due to the severity of the clinical condition, the mass location, which couldn’t be obtained a safe surgical margin and it was financially unviable. The presumptive diagnosis of osteosarcoma was based on clinical history, anamnesis and cytological examination. However, the histopathological examination was essential to confirm the diagnosis. Through immunohistochemical examination, it was found the histogenesis, allowing to exclude other neoplasias. This technic was essential to characterize osteosarcoma due to the shortage reports of this neoplasia in farm animals, therefore, very important in veterinary medicine diagnosis.Keywords: neoplasia, bone, axial skeleton, ruminant, immunohistochemical and anatomopathological aspects