Mesotelioma pleural em mediastino em uma cadela - remoção com esternotomia mediana / Mediastinal mesothelioma in a bitch - removal with median sternotomy

Background: Malignant pleural mesothelioma (MPM) is a neoplasm with low incidence in small animals, and the possible causes are poorly elucidated but may be related to contact with asbestos. In the thoracic cavity, MMP can be localized or generalized to all cavity structures, and its clinical signs depend on this localization. Although some alternative therapies are being discussed, few studies are conclusive, with surgical intervention as the leading therapeutic option. Given this context, this report aimed to describe a case of MMP located in the mediastinum of a bitch treated with radical excision through mediated sternotomy. Case: A 7-year-old bitch of the Shar-pei breed was referred for care due to progressive weight loss and intense dyspnea. During the physical examination, dyspnea and muffled lung sounds were noted. The patient underwent hemodialysis, which showed neutrophilic leukocytosis. An abdominal ultrasound was also performed and revealed mild abdominal effusion, and chest radiography revealed an extensive tumor covering the entire chest cavity. Thoracocentesis was performed, and the material analyzed was a malignant exudate; the patient was referred to median sternotomy for exploratory purposes, and afterward, total macroscopic extirpation of the tumor was performed. A sample was sent for histopathology, and malignant mesothelioma was confirmed. The patient was discharged after 8 days of hospitalization with home treatment and did not return to the hospital. Upon contacting the guardian, we were informed that the animal had died 154 days after the procedure due to unknown causes. Discussion: Malignant pleural mesothelioma affects humans and animals; it is associated with the risk factor of contact with asbestos and the use of flea antiparasitic drugs. In small animals, its incidence is rare, albeit mesotheliomas have been reported in wild and large animals. The clinical signs are related to the location of the neoplasm. When it is located in the thoracic region, dyspnea, muffled lung sounds, cyanosis, and pleural effusion are observed in most cases. Diagnosis is usually late and incidental, although some tests, such as ultrasonography, magnetic resonance imaging, tomography, radiography, and needle biopsy, can help in the diagnosis. Histopathology is the exam of choice for definitive diagnosis, as it helps one observe the proliferation of neoplastic mesothelial cells, atypical mitosis figures, and marked cellular pleomorphism. Many therapeutic options have been discussed, including chemotherapy, immunotherapy, and anti-tumor immunization, although there is little scientific proof of their efficacy in animals. The current treatment of choice is tumor excision by surgical procedure with a palliative objective since the prognosis of the disease is unfavorable. Minimally invasive video surgery has been gaining more and more space in veterinary medicine and has proven successful in numerous cases of thoracic masses. In the present report, we chose to perform median sternotomy for total excision due to the extension of the mass that occupied the thoracic cavity practically in its entirety. Further research should be conducted to help in palliative treatments and increase the survival of patients with mesotheliomas, given that most studies are done in humans and not animals. We conclude that median sternotomy is still the therapeutic option of choice for the palliative treatment of patients with extensive thoracic pleural mesotheliomas.

Metastatic papillary mesothelioma in a dog: a case report

A six-year-old female Dachshund presented intense abdominal distension caused by hemorrhagic effusion. Cytological examination of the fluid was performed and suggested a carcinoma. The animal was submitted to exploratory laparotomy and histological examination of the substantially altered spleen revealed epithelioid mesothelioma. Owing to a poor prognosis, poor response to chemotherapy, and development of thoracic effusions that required daily drainages, the owners decided for euthanasia. At necropsy, besides a 600 mL of sera‐hemorrhagic abdominal fluid, no abnormal gross finding was identified in the abdominal cavity. The thoracic cavity was also filled with approximately 200 mL of effusion with same features as those detected in the abdominal fluid. A few firm white-to-gray nodules, with sizes ranging from 0.1 to 0.3 cm, were found in the lungs and diaphragm. Samples of the nodules were stained for routine histopathology and submitted to immunohistochemistry (IHC) assays using the antibodies vimentin, PAN Cytokeratin, calretinin, and TTF-1. Histopathology and IHC findings confirmed the diagnosis of metastatic papillary mesothelioma.

Metastatic papillary mesothelioma in a dog: a case report

A six-year-old female Dachshund presented intense abdominal distension caused by hemorrhagic effusion. Cytological examination of the fluid was performed and suggested a carcinoma. The animal was submitted to exploratory laparotomy and histological examination of the substantially altered spleen revealed epithelioid mesothelioma. Owing to a poor prognosis, poor response to chemotherapy, and development of thoracic effusions that required daily drainages, the owners decided for euthanasia. At necropsy, besides a 600 mL of sera‐hemorrhagic abdominal fluid, no abnormal gross finding was identified in the abdominal cavity. The thoracic cavity was also filled with approximately 200 mL of effusion with same features as those detected in the abdominal fluid. A few firm white-to-gray nodules, with sizes ranging from 0.1 to 0.3 cm, were found in the lungs and diaphragm. Samples of the nodules were stained for routine histopathology and submitted to immunohistochemistry (IHC) assays using the antibodies vimentin, PAN Cytokeratin, calretinin, and TTF-1. Histopathology and IHC findings confirmed the diagnosis of metastatic papillary mesothelioma.(AU)

Neoplasmas encefálicos em cães idosos / Brain neoplasms in elderly dogs

Background: The prevalence of intracranial neoplasms in dogs represents 2.1 to 4.0% of the cases. Brain tumors may beprimary or metastatic. The objective of this study was to describe two cases of intra encephalic neoplasia in elderly dogsreceived for necropsy by the Veterinary Oncology Service in the Federal University of Pelotas.Cases: Case 1: A 12-year-old female canine, without breed and medium size, was received for necropsy. The animal hashad behavioral changes. Macroscopic examination of the encephalus revealed asymmetry and congestion. The organs werecollected and fixed in 10% formalin. In the brain cleavage we noticed an extensive brown-gray mass with reddish areas,expansive, moderately demarcated, soft to cut and discrete hydrocephalus. Serial fragments of the brain and fragmentsof the organs were sent for processing. The slides were stained with the hematoxylin and eosin technique for histopathological analysis. At the microscopic examination, cuboidal cells were observed in the encephalus sometimes in acinar arrangements, of extensive and very limited pattern, diagnosed as ependymoma. Case 2: It is a 15-year-old, female Poodledog, with several tumors. During necropsy multiple subcutaneous nodules, mesentery, intestinal serosa, stomach and liverwere noticed. At the cut these were firm and whitish. No macroscopic changes were observed in the other organs. Fragments of organs and brain were collected and a serial section of the encephalus was performed for further processing andhistological analysis. In the histopathological analysis the masses were constituted by proliferation of sometimes roundedcells, elongated, with rounded nuclei and eosinophilic cytoplasm, allowing the diagnosis of mesothelioma. The samecell pattern was observed in other organs. In the frontal cortex of the encephalus there were small foci of cells similar tothose observed in the mesentery, as well as metastatic...(AU)

Neoplasmas encefálicos em cães idosos / Brain neoplasms in elderly dogs

Background: The prevalence of intracranial neoplasms in dogs represents 2.1 to 4.0% of the cases. Brain tumors may beprimary or metastatic. The objective of this study was to describe two cases of intra encephalic neoplasia in elderly dogsreceived for necropsy by the Veterinary Oncology Service in the Federal University of Pelotas.Cases: Case 1: A 12-year-old female canine, without breed and medium size, was received for necropsy. The animal hashad behavioral changes. Macroscopic examination of the encephalus revealed asymmetry and congestion. The organs werecollected and fixed in 10% formalin. In the brain cleavage we noticed an extensive brown-gray mass with reddish areas,expansive, moderately demarcated, soft to cut and discrete hydrocephalus. Serial fragments of the brain and fragmentsof the organs were sent for processing. The slides were stained with the hematoxylin and eosin technique for histopathological analysis. At the microscopic examination, cuboidal cells were observed in the encephalus sometimes in acinar arrangements, of extensive and very limited pattern, diagnosed as ependymoma. Case 2: It is a 15-year-old, female Poodledog, with several tumors. During necropsy multiple subcutaneous nodules, mesentery, intestinal serosa, stomach and liverwere noticed. At the cut these were firm and whitish. No macroscopic changes were observed in the other organs. Fragments of organs and brain were collected and a serial section of the encephalus was performed for further processing andhistological analysis. In the histopathological analysis the masses were constituted by proliferation of sometimes roundedcells, elongated, with rounded nuclei and eosinophilic cytoplasm, allowing the diagnosis of mesothelioma. The samecell pattern was observed in other organs. In the frontal cortex of the encephalus there were small foci of cells similar tothose observed in the mesentery, as well as metastatic...

Fatal hemothorax caused by pleural mesothelioma in a lion / Hemotórax fatal causado por mesotelioma pleural em um leão

Mesothelioma is considered a malignant neoplasm caused by the proliferation of mesothelial cells mostly from the pleura, peritoneum and pericardium. Here we described a case of fatal hemothorax caused by pleural mesothelioma in a lion by means of necropsy, histopathology and immunohistochemistry. Gross inspection of the thoracic cavity showed hemothorax with about 4 liters of blood. Microscopically, numerous, randomly distributed, soft, red-pink, irregular masses with up to 1cm in diameter were observed in both visceral and parietal pleurae. Microscopically, a papillary structure pattern was observed in the thoracic masses, composed mainly by one layer of cubic mesothelial cells, which presented eosinophilic cytoplasm, central nucleus and evident nucleolus, supported by a low cellular fibrovascularstroma. Neoplastic cells were positive for both cytokeratin and vimentin by immunohistochemistry. This seems to be the first report of fatal hemothorax caused by pleural mesothelioma in a lion.(AU)

O mesotelioma é considerado um neoplasma maligna causada pela proliferação de células mesoteliais, principalmente da pleura, peritôneo e pericárdio. O presente caso descreve os achados macroscópicos, microscópicos e imuno-histoquímicos do hemotórax fatal causado por um mesotelioma pleural em um leão. Macroscopicamente, na cavidade torácica, foi observado cerca de 4 litros de sangue. Além disso, foram observadas numerosas massas macias, vermelho-rosa, irregulares, com até 1cm de diâmetro e distribuídas aleatoriamente pelas pleuras parietal e visceral. Microscopicamente, as massas torácicas apresentavam estruturas papilares, compostas por uma camada de células mesoteliais, que apresentavam citoplasma eosinofílico, núcleo central e nucléolo evidente, suportada por um estroma fibrovascular pouco celular. A imuno-histoquímica foi positiva para ambas citoqueratina e vimentina nas células neoplásicas. Este trabalho descreve o que parece ser o primeiro relato de um hemotórax fatal causado por um mesotelioma pleural em um leão.(AU)

Fatal hemothorax caused by pleural mesothelioma in a lion / Hemotórax fatal causado por mesotelioma pleural em um leão

Mesothelioma is considered a malignant neoplasm caused by the proliferation of mesothelial cells mostly from the pleura, peritoneum and pericardium. Here we described a case of fatal hemothorax caused by pleural mesothelioma in a lion by means of necropsy, histopathology and immunohistochemistry. Gross inspection of the thoracic cavity showed hemothorax with about 4 liters of blood. Microscopically, numerous, randomly distributed, soft, red-pink, irregular masses with up to 1cm in diameter were observed in both visceral and parietal pleurae. Microscopically, a papillary structure pattern was observed in the thoracic masses, composed mainly by one layer of cubic mesothelial cells, which presented eosinophilic cytoplasm, central nucleus and evident nucleolus, supported by a low cellular fibrovascularstroma. Neoplastic cells were positive for both cytokeratin and vimentin by immunohistochemistry. This seems to be the first report of fatal hemothorax caused by pleural mesothelioma in a lion.(AU)

O mesotelioma é considerado um neoplasma maligna causada pela proliferação de células mesoteliais, principalmente da pleura, peritôneo e pericárdio. O presente caso descreve os achados macroscópicos, microscópicos e imuno-histoquímicos do hemotórax fatal causado por um mesotelioma pleural em um leão. Macroscopicamente, na cavidade torácica, foi observado cerca de 4 litros de sangue. Além disso, foram observadas numerosas massas macias, vermelho-rosa, irregulares, com até 1cm de diâmetro e distribuídas aleatoriamente pelas pleuras parietal e visceral. Microscopicamente, as massas torácicas apresentavam estruturas papilares, compostas por uma camada de células mesoteliais, que apresentavam citoplasma eosinofílico, núcleo central e nucléolo evidente, suportada por um estroma fibrovascular pouco celular. A imuno-histoquímica foi positiva para ambas citoqueratina e vimentina nas células neoplásicas. Este trabalho descreve o que parece ser o primeiro relato de um hemotórax fatal causado por um mesotelioma pleural em um leão.(AU)

Mesotelioma pleural em um cão da raça rottweiler / Pleural mesothelioma in a rottweiler dog breed

O mesotelioma é uma neoplasia difusa das membranas serosas da pleura, peritônio, pericárdio e túnica vaginal. É rara em todas as espécies animais. Os sinais clínicos apresentados são secundários ao acúmulo de efusão intracavitária característico deste tipo de tumor. Observam-se dispneia, aumento de volume abdominal, sinais de insuficiência cardíaca congestiva direita, entre outros. O diagnóstico definitivo é obtido através do exame histopatológico. Não existe tratamento efetivo. A cisplatina é a droga de escolha para a terapia paliativa. Neste trabalho é relatado um caso de mesotelioma pleural, diagnosticado na necropsia, em um cão macho da raça rottweiler. A doença apresentou-se rapidamente progressiva, havendo um curto intervalo desde o primeiro atendimento até o óbito do paciente. Clinicamente apresentava muita dispneia em função do acúmulo de efusão hemorrágica intrapleural, sendo a terapia adotada baseada nos sinais clínicos e exames complementares. É, sem dúvida, uma neoplasia com prognóstico bastante desfavorável.

Mesothelioma is a diffuse neoplasia of the membranes serous pleura, pericardium, peritoneum and tunica vaginalis. It is rare in all animal species. The clinical signs are secondary to the intracavitary increase of effusion, characteristic of this type of tumor. It is also observed dyspnea, increase of abdominal volume, signs of direct congestive cardiac insufficient, among others. The final diagnosis is achieved with histopathological test. There is no effective treatment. Cisplatin is the drug of choice for palliative therapy. This paper reports a case of pleural mesothelioma, diagnosable in necropsy of a Rottweiler male dog. The disease was progressive, with a brief interval since the first treatment, until the death of the patient. Clinically, the dog appeared to suffer great dyspnea due the increase of intrapleural hemorrhagic effusion. The adopted therapy was based in clinical signs and complementary clinical tests. This neoplasia has, indubitably, an unfavorable prognosis.

Mesotelioma pleural em um cão da raça rottweiler / Pleural mesothelioma in a rottweiler dog breed

O mesotelioma é uma neoplasia difusa das membranas serosas da pleura, peritônio, pericárdio e túnica vaginal. É rara em todas as espécies animais. Os sinais clínicos apresentados são secundários ao acúmulo de efusão intracavitária característico deste tipo de tumor. Observam-se dispneia, aumento de volume abdominal, sinais de insuficiência cardíaca congestiva direita, entre outros. O diagnóstico definitivo é obtido através do exame histopatológico. Não existe tratamento efetivo. A cisplatina é a droga de escolha para a terapia paliativa. Neste trabalho é relatado um caso de mesotelioma pleural, diagnosticado na necropsia, em um cão macho da raça rottweiler. A doença apresentou-se rapidamente progressiva, havendo um curto intervalo desde o primeiro atendimento até o óbito do paciente. Clinicamente apresentava muita dispneia em função do acúmulo de efusão hemorrágica intrapleural, sendo a terapia adotada baseada nos sinais clínicos e exames complementares. É, sem dúvida, uma neoplasia com prognóstico bastante desfavorável.(AU)

Mesothelioma is a diffuse neoplasia of the membranes serous pleura, pericardium, peritoneum and tunica vaginalis. It is rare in all animal species. The clinical signs are secondary to the intracavitary increase of effusion, characteristic of this type of tumor. It is also observed dyspnea, increase of abdominal volume, signs of direct congestive cardiac insufficient, among others. The final diagnosis is achieved with histopathological test. There is no effective treatment. Cisplatin is the drug of choice for palliative therapy. This paper reports a case of pleural mesothelioma, diagnosable in necropsy of a Rottweiler male dog. The disease was progressive, with a brief interval since the first treatment, until the death of the patient. Clinically, the dog appeared to suffer great dyspnea due the increase of intrapleural hemorrhagic effusion. The adopted therapy was based in clinical signs and complementary clinical tests. This neoplasia has, indubitably, an unfavorable prognosis.(AU)

Mesotelioma pleural com metástase renal em gato / Pleural mesothelioma with renal metastasis in a cat

It has been described the anatomopathological and immunohistochemical characteristics of a multinodular neoplasm distributed in the parietal and visceral pleurae, pericardium, thoracic portion of the diaphragm and renal cortex of an eight year-old, female, mixed breed, cat. Based on the anatomopathological and immunohistochemical findings it was firmed the diagnosis of biphasic pleural mesotelioma with renal metastasis.(AU)

Mesotelioma peritoneal em cão: relato de caso / Peritoneal mesothelioma in dog: a case report

Este estudo descreve os achados anatomopatológicos e imuno-histoquímicos do mesotelioma peritoneal em um cão de raça Setter, de nove anos de idade e sem histórico clínico. A necropsia, foram observados vários nódulos que variavam de alguns milímetros a 2cm de diâmetro, de superfície lisa, esbranquiçados, firmes e distribuídos amplamente pelos peritônios parietal e visceral dos órgaos abdominais e pelo funículo espermático. Histologicamente foram evidenciados ninhos de células mesoteliais neoplásicas envoltos por grande quantidade de tecido conjuntivo fibroso. Essas células apresentavam-se fusiformes ou epitelióides com citoplasma vacuolizado e núcleo oval com cromatina frouxa e nucléolo evidente. Havia também algumas formações císticas revestidas por uma ou mais camadas de células neoplásicas achatadas ou colunares e com o lúmen ocupado por debris celulares e material eosinofílico, PAS-positivo. Areas de metaplasia cartilaginosa e de necrose também forma visualizadas. O resultado das reações imumo-histoquímicas revelou a presença de células neoplásicas com imunomarcações fortes e difusas para proteína S100 e para citoqueratina (AE/AE3) e ausência de marcação para vimentina e para o antígeno carcinoembrionário (CEA). A imunomarcação das células neoplásicas com a utilização do anticorpo contra célula mesotelial humana (HBME-1) foi forte e multifocal. Com base nos achados anatomopatalógicos e imuno-histoquímico, firmou-se o diagnóstico de mesotelioma peritoneal esclerosante

This study describes the anatomopathological and immunohistochemical findings of a canine peritoneal mesothelioma. A nine-year-old male Setter with no clinical history was submitted to necropsy. Macroscopically, many whitish firm nodules ranging from a few milimeters to 2cm in diameter were found in the abdominal cavity. These nodules had a smooth surface and were scattered throughout the parietal and visceral peritoneum and also on the spermatic cord. Histologically, neoplastic mesothelial cell groups surrounded by a large amount of fibrous connective tissue were observed. These cells were either spindle shaped or epithelioid with a vacuolated cytoplasm and oval nuclei with granular chromatin and prominent nucleoli. Many cystic spaces lined by a single or many layers of flat or columnar neoplastic cells were observed. These cysts were filled with PAS-positive eosinophilic material. Cartilaginous metaplasia and necrosis were also detected. The mesothelial cells showed intense and diffuse immunoreactivity for protein S100 and cytokeratin (AE1/AE3), however there were no reactivity for vimentin and CEA and the reactivity for human mesothelial anti-cell (HBME-1) was strong and multifocal. Based on the histopathological and immunohistochemical findings the diagnosis of sclerosing peritoneal mesothelioma was made.

Mesotelioma peritoneal em cão: relato de caso / Peritoneal mesothelioma in dog: a case report

Este estudo descreve os achados anatomopatológicos e imuno-histoquímicos do mesotelioma peritoneal em um cão de raça Setter, de nove anos de idade e sem histórico clínico. A necropsia, foram observados vários nódulos que variavam de alguns milímetros a 2cm de diâmetro, de superfície lisa, esbranquiçados, firmes e distribuídos amplamente pelos peritônios parietal e visceral dos órgaos abdominais e pelo funículo espermático. Histologicamente foram evidenciados ninhos de células mesoteliais neoplásicas envoltos por grande quantidade de tecido conjuntivo fibroso. Essas células apresentavam-se fusiformes ou epitelióides com citoplasma vacuolizado e núcleo oval com cromatina frouxa e nucléolo evidente. Havia também algumas formações císticas revestidas por uma ou mais camadas de células neoplásicas achatadas ou colunares e com o lúmen ocupado por debris celulares e material eosinofílico, PAS-positivo. Areas de metaplasia cartilaginosa e de necrose também forma visualizadas. O resultado das reações imumo-histoquímicas revelou a presença de células neoplásicas com imunomarcações fortes e difusas para proteína S100 e para citoqueratina (AE/AE3) e ausência de marcação para vimentina e para o antígeno carcinoembrionário (CEA). A imunomarcação das células neoplásicas com a utilização do anticorpo contra célula mesotelial humana (HBME-1) foi forte e multifocal. Com base nos achados anatomopatalógicos e imuno-histoquímico, firmou-se o diagnóstico de mesotelioma peritoneal esclerosante (AU)

This study describes the anatomopathological and immunohistochemical findings of a canine peritoneal mesothelioma. A nine-year-old male Setter with no clinical history was submitted to necropsy. Macroscopically, many whitish firm nodules ranging from a few milimeters to 2cm in diameter were found in the abdominal cavity. These nodules had a smooth surface and were scattered throughout the parietal and visceral peritoneum and also on the spermatic cord. Histologically, neoplastic mesothelial cell groups surrounded by a large amount of fibrous connective tissue were observed. These cells were either spindle shaped or epithelioid with a vacuolated cytoplasm and oval nuclei with granular chromatin and prominent nucleoli. Many cystic spaces lined by a single or many layers of flat or columnar neoplastic cells were observed. These cysts were filled with PAS-positive eosinophilic material. Cartilaginous metaplasia and necrosis were also detected. The mesothelial cells showed intense and diffuse immunoreactivity for protein S100 and cytokeratin (AE1/AE3), however there were no reactivity for vimentin and CEA and the reactivity for human mesothelial anti-cell (HBME-1) was strong and multifocal. Based on the histopathological and immunohistochemical findings the diagnosis of sclerosing peritoneal mesothelioma was made. (AU)