Pathology of severe urolithiasis in a flock of egg-laying hens

Fourteen, 31-week-old Lohmann white layers from a flock of 30,000 chickens had a history of apathy, and a drop in egg production. Clinical signs were observed in approximately 40% of the flock, and lasted for three months. Fourteen hens were euthanized for post-mortem examinations. Macroscopic findings included marked atrophy and loss of renal lobes along with compensatory renal hypertrophy of the contralateral lobe. Ureters were markedly dilated and filled with mucus and/or with molded white to yellow-grey uroliths that obliterated the lumen. At histopathology, the uroliths inside ureters and tubules were composed of concentrically arranged mineralized concretions, as well as urates associated with heterophilic infiltrations and epithelial hyperplasia. Renal parenchyma adjacent to obstructed ureters was compressed with tubules replaced by fibrous tissue. Multifocal interstitial lymphocytic nephritis, proteinuria and membranoproliferative glomerulonephritis were also found. Heterophilic and caseous ureteritis associated with numerous Gram-positive coccoid bacteria occurred in three chickens. Immunohistochemistry for avian coronavirus was negative. This negative result along with the case history indicated that water restriction was the most likely cause of mortality. This condition resulted in significant economic loss for this farmer.(AU)

Pathology of severe urolithiasis in a flock of egg-laying hens

Fourteen, 31-week-old Lohmann white layers from a flock of 30,000 chickens had a history of apathy, and a drop in egg production. Clinical signs were observed in approximately 40% of the flock, and lasted for three months. Fourteen hens were euthanized for post-mortem examinations. Macroscopic findings included marked atrophy and loss of renal lobes along with compensatory renal hypertrophy of the contralateral lobe. Ureters were markedly dilated and filled with mucus and/or with molded white to yellow-grey uroliths that obliterated the lumen. At histopathology, the uroliths inside ureters and tubules were composed of concentrically arranged mineralized concretions, as well as urates associated with heterophilic infiltrations and epithelial hyperplasia. Renal parenchyma adjacent to obstructed ureters was compressed with tubules replaced by fibrous tissue. Multifocal interstitial lymphocytic nephritis, proteinuria and membranoproliferative glomerulonephritis were also found. Heterophilic and caseous ureteritis associated with numerous Gram-positive coccoid bacteria occurred in three chickens. Immunohistochemistry for avian coronavirus was negative. This negative result along with the case history indicated that water restriction was the most likely cause of mortality. This condition resulted in significant economic loss for this farmer.

Differential diagnoses in 83 dogs with icterus / Diagnósticos diferenciais em 83 cães com icterícia

Icterus (jaundice) is a yellowish pigmentation resulting from the depositing of bilirubin in tissues due to its high plasmatic concentration. The pathogenesis of icterus includes metabolic changes or obstructed bilirubin excretion and it is classified as pre-hepatic, hepatic and post-hepatic. This study aimed to evaluate and classify different causes of icterus in dogs during post mortem examination. These dogs were examined from 2014 to 2017, using macroscopic and histologic exams as well as ancillary tests. Eighty-three dogs were examined macroscopically and microscopically. They were separated into groups of icterus types: 24 (28.9%) dogs had pre-hepatic icterus, 45 (54.2%) had hepatic, 13 (15.7%) pre-hepatic and hepatic and one (1.2%) had post-hepatic icterus. Many factors were identified as a cause of icterus, including infectious agents (51/83), neoplasms (13/83), hepatic degeneration (11/83), chronic hepatic diseases (6/83), and obstructive causes (1/87). Among the infectious causes, leptospirosis, ehrlichiosis and disorders suggestive of septicemia were diagnosed. Neoplasms associated with icterus were cholangiocarcinoma, hemangiosarcoma and lymphoma. Other causes of icterus included degenerative diseases, such as lipidosis and glycogen degeneration. Hepatic fibrosis (cirrhosis) as a chronic disease and cholelithiasis also produced icterus. PCR was performed to confirm leptospirosis and ehrlichiosis. Samples of total DNA were used to amplify a fragment of a gene from Leptospira interrogans and Ehrlichia canis. In some dogs, co-infection of these agents was detected. The classification and identification of icterus etiologies in dogs is very important due to the number of diseases with this alteration, where ante mortem diagnosis is not always easily performed when some of these conditions are present.(AU)

Icterícia é a pigmentação amarelada decorrente da deposição de bilirrubina em tecidos devido à elevada concentração plasmática. A patogênese da icterícia inclui alterações no metabolismo ou na excreção de bilirrubina, sendo classificada em pré-hepática, hepática ou pós-hepática. O objetivo desse estudo foi identificar, avaliar e classificar as causas de icterícia em cães necropsiados de 2014 a 2017, associando as lesões macroscópicas, histológicas e exames complementares. Foram avaliados macro- e microscopicamente 83 cães com diferentes intensidades de icterícia. Os cães foram separados em grupos de acordo com o tipo de icterícia: 24 (28,9%) cães com icterícia pré-hepática, 45 (54,2%) cães com icterícia hepática, 13 (15,7%) com icterícia pré-hepática e hepática e um (1,2%) com icterícia pós-hepática. Foram identificadas várias etiologias associadas à icterícia, dentre elas pode-se destacar, agentes infecciosos (51/83), neoplasmas (13/83), processos degenerativos (11/83), crônicos (6/83) e obstrutivos (1/83). Dentre as causas infecciosas, destacam-se a leptospirose, a erliquiose e as lesões sugestivas de septicemia. Entre os neoplasmas associados com icterícia destacaram-se o colangiocarcinoma, hemangiossarcoma e linfoma. Outras causas de icterícia incluiriam os processos degenerativos como as degenerações gordurosa e glicogênica. Fibrose hepática (cirrose) e colelitíase foram também diagnosticados como causa de icterícia. A PCR foi utilizada para o diagnóstico confirmatório de leptospirose e erliquiose. Amostras de DNA total foram utilizadas para amplificar um fragmento dos genes de Leptospira interrogans e de Ehrlichia canis. Em alguns cães foi detectada co-infecção por estes agentes. A classificação e a identificação das causas de icterícia em cães são relevantes devido ao grande número de doenças que apresentam essa alteração, muitas vezes sem diagnóstico ante mortem.(AU)

Differential diagnoses in 83 dogs with icterus / Diagnósticos diferenciais em 83 cães com icterícia

Icterus (jaundice) is a yellowish pigmentation resulting from the depositing of bilirubin in tissues due to its high plasmatic concentration. The pathogenesis of icterus includes metabolic changes or obstructed bilirubin excretion and it is classified as pre-hepatic, hepatic and post-hepatic. This study aimed to evaluate and classify different causes of icterus in dogs during post mortem examination. These dogs were examined from 2014 to 2017, using macroscopic and histologic exams as well as ancillary tests. Eighty-three dogs were examined macroscopically and microscopically. They were separated into groups of icterus types: 24 (28.9%) dogs had pre-hepatic icterus, 45 (54.2%) had hepatic, 13 (15.7%) pre-hepatic and hepatic and one (1.2%) had post-hepatic icterus. Many factors were identified as a cause of icterus, including infectious agents (51/83), neoplasms (13/83), hepatic degeneration (11/83), chronic hepatic diseases (6/83), and obstructive causes (1/87). Among the infectious causes, leptospirosis, ehrlichiosis and disorders suggestive of septicemia were diagnosed. Neoplasms associated with icterus were cholangiocarcinoma, hemangiosarcoma and lymphoma. Other causes of icterus included degenerative diseases, such as lipidosis and glycogen degeneration. Hepatic fibrosis (cirrhosis) as a chronic disease and cholelithiasis also produced icterus. PCR was performed to confirm leptospirosis and ehrlichiosis. Samples of total DNA were used to amplify a fragment of a gene from Leptospira interrogans and Ehrlichia canis. In some dogs, co-infection of these agents was detected. The classification and identification of icterus etiologies in dogs is very important due to the number of diseases with this alteration, where ante mortem diagnosis is not always easily performed when some of these conditions are present.(AU)

Icterícia é a pigmentação amarelada decorrente da deposição de bilirrubina em tecidos devido à elevada concentração plasmática. A patogênese da icterícia inclui alterações no metabolismo ou na excreção de bilirrubina, sendo classificada em pré-hepática, hepática ou pós-hepática. O objetivo desse estudo foi identificar, avaliar e classificar as causas de icterícia em cães necropsiados de 2014 a 2017, associando as lesões macroscópicas, histológicas e exames complementares. Foram avaliados macro- e microscopicamente 83 cães com diferentes intensidades de icterícia. Os cães foram separados em grupos de acordo com o tipo de icterícia: 24 (28,9%) cães com icterícia pré-hepática, 45 (54,2%) cães com icterícia hepática, 13 (15,7%) com icterícia pré-hepática e hepática e um (1,2%) com icterícia pós-hepática. Foram identificadas várias etiologias associadas à icterícia, dentre elas pode-se destacar, agentes infecciosos (51/83), neoplasmas (13/83), processos degenerativos (11/83), crônicos (6/83) e obstrutivos (1/83). Dentre as causas infecciosas, destacam-se a leptospirose, a erliquiose e as lesões sugestivas de septicemia. Entre os neoplasmas associados com icterícia destacaram-se o colangiocarcinoma, hemangiossarcoma e linfoma. Outras causas de icterícia incluiriam os processos degenerativos como as degenerações gordurosa e glicogênica. Fibrose hepática (cirrose) e colelitíase foram também diagnosticados como causa de icterícia. A PCR foi utilizada para o diagnóstico confirmatório de leptospirose e erliquiose. Amostras de DNA total foram utilizadas para amplificar um fragmento dos genes de Leptospira interrogans e de Ehrlichia canis. Em alguns cães foi detectada co-infecção por estes agentes. A classificação e a identificação das causas de icterícia em cães são relevantes devido ao grande número de doenças que apresentam essa alteração, muitas vezes sem diagnóstico ante mortem.(AU)

Esophageal squamous cell carcinoma in a backyard rooster

Squamous cell carcinoma, a malignant epithelial neoplasm originating from the epidermis squamous cells or the digestive mucosa epithelium, was diagnosed in an adult rooster. The rooster was lethargic and presented difficulties in swallowing. Physical examination revealed a large deep mass in the cranial cervical region. Due to poor prognosis, the bird was euthanized and then post mortem examined. Grossly, in the oral portion of the esophagus, there was a mass invading and partially occluding the lumen. Microscopically, the mass had neoplastic cells interconnected by evident desmosomes junctions and keratin pearl formations. Microscopic findings confirmed the diagnosis of squamous cell carcinoma. This neoplasia is an important differential diagnosis for esophageal lesions in birds. There are various carcinogens for squamous cell carcinoma such as sunlight, virus, some chemicals and chronic wounds, the last one being a possible cause of the squamous cell carcinoma in this rooster as no evidence of other etiologies were found.

Esophageal squamous cell carcinoma in a backyard rooster

Squamous cell carcinoma, a malignant epithelial neoplasm originating from the epidermis squamous cells or the digestive mucosa epithelium, was diagnosed in an adult rooster. The rooster was lethargic and presented difficulties in swallowing. Physical examination revealed a large deep mass in the cranial cervical region. Due to poor prognosis, the bird was euthanized and then post mortem examined. Grossly, in the oral portion of the esophagus, there was a mass invading and partially occluding the lumen. Microscopically, the mass had neoplastic cells interconnected by evident desmosomes junctions and keratin pearl formations. Microscopic findings confirmed the diagnosis of squamous cell carcinoma. This neoplasia is an important differential diagnosis for esophageal lesions in birds. There are various carcinogens for squamous cell carcinoma such as sunlight, virus, some chemicals and chronic wounds, the last one being a possible cause of the squamous cell carcinoma in this rooster as no evidence of other etiologies were found.(AU)

Prospective study of ocular and periocular diseases in animals: 188 cases / Estudo prospectivo de doenças oculares e perioculares em animais: 188 casos

istopathology of the ocular and periocular tissues submitted for diagnosis and research is still incipient in Brazil, in contrast to veterinary clinical ophthalmology. In this study, ocular and periocular tissues from domestic and wild animal species, mainly from the state of Minas Gerais, Brazil, were evaluated between February 2012 and September 2015. The samples were analyzed grossly and microscopically. Histochemistry and immunohistochemistry were performed on some of the samples. The frequency, type of ocular alteration, affected animal species, and affected ocular or periocular tissues were recorded. One hundred eighty-eight ocular and periocular tissues from domestic and, occasionally, wild animals were examined. Nine animals presented two concurrent alterations, adding up to 197 alterations. Proliferative lesions were the most frequent (92), followed by traumatic (43), inflammatory (37), degenerative (18), developmental (4) and vascular/hemorrhagic diseases (3). The globe was the most affected structure (112), followed by eyelids (52), third eyelid (17), bulbar conjunctiva (14) and retrobulbar region (2). Neoplasms arising from periocular tissues were the most frequent alteration (60), possibly related to a more active surgical service and histopathologic evaluation request. Many animals presented ocular lesions that reflected systemic diseases, which were diagnosed by necropsy and examination of other organs. Particularly in cases of neoplasia, early detection and surgical treatment can prevent systemic involvement. Ocular histopathologic evaluation can provide better characterization and prognosis of the clinical-pathological condition of the patient as well.(AU)

O envio de bulbos oculares e tecidos perioculares para histopatologia na rotina diagnóstica e pesquisa ainda é incipiente no Brasil, diferentemente da área de oftalmologia clínica veterinária. Neste estudo, olhos e tecidos perioculares de animais domésticos e silvestres, especialmente provenientes do estado de Minas Gerais, Brasil, foram avaliados entre fevereiro de 2012 e setembro de 2015. As amostras foram analisadas macro e microscopicamente. Em algumas amostras, histoquímica e imuno-histoquímica também foram realizadas. Frequência, tipo de alteração ocular, espécie animal e estrutura ocular e/ou periocular acometidas foram registrados. Foram examinados 188 bulbos oculares e tecidos perioculares de animais domésticos e, ocasionalmente, silvestres. Nove animais apresentaram duas alterações concomitantes, totalizando 197 alterações. Doenças neoplásicas foram as mais frequentes (92), seguidas pelas traumáticas (43), inflamatórias (37), degenerativas (18), de desenvolvimento (4) e vasculares/hemorrágicas (3). O bulbo ocular foi a estrutura mais acometida (112), seguida pelas pálpebras (52), terceira pálpebra (17), conjuntiva bulbar (14) e região retrobulbar (2). Neoplasmas com origem em tecido periocular foram a alteração mais frequente (60), possivelmente relacionado a uma rotina cirúrgica mais ativa e consequente solicitação de avaliação histopatológica. Muitos animais apresentaram lesões oculares como reflexo de doença sistêmica, as quais foram diagnosticadas por necropsia e análise de outros órgãos. Particularmente em casos de neoplasia, detecção precoce e tratamento cirúrgico podem evitar envolvimento sistêmico. Ademais, a avaliação histopatológica ocular é capaz de oferecer melhor caracterização e prognóstico de condições clínico-patológicas do paciente animal.(AU)

Prospective study of ocular and periocular diseases in animals: 188 cases / Estudo prospectivo de doenças oculares e perioculares em animais: 188 casos

Histopathology of the ocular and periocular tissues submitted for diagnosis and research is still incipient in Brazil, in contrast to veterinary clinical ophthalmology. In this study, ocular and periocular tissues from domestic and wild animal species, mainly from the state of Minas Gerais, Brazil, were evaluated between February 2012 and September 2015. The samples were analyzed grossly and microscopically. Histochemistry and immunohistochemistry were performed on some of the samples. The frequency, type of ocular alteration, affected animal species, and affected ocular or periocular tissues were recorded. One hundred eighty-eight ocular and periocular tissues from domestic and, occasionally, wild animals were examined. Nine animals presented two concurrent alterations, adding up to 197 alterations. Proliferative lesions were the most frequent (92), followed by traumatic (43), inflammatory (37), degenerative (18), developmental (4) and vascular/hemorrhagic diseases (3). The globe was the most affected structure (112), followed by eyelids (52), third eyelid (17), bulbar conjunctiva (14) and retrobulbar region (2). Neoplasms arising from periocular tissues were the most frequent alteration (60), possibly related to a more active surgical service and histopathologic evaluation request. Many animals presented ocular lesions that reflected systemic diseases, which were diagnosed by necropsy and examination of other organs. Particularly in cases of neoplasia, early detection and surgical treatment can prevent systemic involvement. Ocular histopathologic evaluation can provide better characterization and prognosis of the clinical-pathological condition of the patient as well.(AU)

O envio de bulbos oculares e tecidos perioculares para histopatologia na rotina diagnóstica e pesquisa ainda é incipiente no Brasil, diferentemente da área de oftalmologia clínica veterinária. Neste estudo, olhos e tecidos perioculares de animais domésticos e silvestres, especialmente provenientes do estado de Minas Gerais, Brasil, foram avaliados entre fevereiro de 2012 e setembro de 2015. As amostras foram analisadas macro e microscopicamente. Em algumas amostras, histoquímica e imuno-histoquímica também foram realizadas. Frequência, tipo de alteração ocular, espécie animal e estrutura ocular e/ou periocular acometidas foram registrados. Foram examinados 188 bulbos oculares e tecidos perioculares de animais domésticos e, ocasionalmente, silvestres. Nove animais apresentaram duas alterações concomitantes, totalizando 197 alterações. Doenças neoplásicas foram as mais frequentes (92), seguidas pelas traumáticas (43), inflamatórias (37), degenerativas (18), de desenvolvimento (4) e vasculares/hemorrágicas (3). O bulbo ocular foi a estrutura mais acometida (112), seguida pelas pálpebras (52), terceira pálpebra (17), conjuntiva bulbar (14) e região retrobulbar (2). Neoplasmas com origem em tecido periocular foram a alteração mais frequente (60), possivelmente relacionado a uma rotina cirúrgica mais ativa e consequente solicitação de avaliação histopatológica. Muitos animais apresentaram lesões oculares como reflexo de doença sistêmica, as quais foram diagnosticadas por necropsia e análise de outros órgãos. Particularmente em casos de neoplasia, detecção precoce e tratamento cirúrgico podem evitar envolvimento sistêmico. Ademais, a avaliação histopatológica ocular é capaz de oferecer melhor caracterização e prognóstico de condições clínico-patológicas do paciente animal.(AU)

Hemosuccus = pancreaticus in a dog: A rare case of gastrointestinal hemorrhage

A 9-year-old, 5.5-kg (12.12-lb) spayed female Poodle was evaluated due to recurrent seizures and possible diabetes. The dog also had a history of anorexia, polyuria and polydipsia. Serum biochemistry results revealed increases in pancreatic amylase and glucose associated with decreased protein levels. Abdominal ultrasound suggested acute pancreatitis and/or a pancreatic tumor with intense peripancreatic vascularization. The clinical condition of the dog worsened despite medical treatment, and death occurred shortly thereafter. At necropsy, blood clots were found in the stomach and in the intestinal lumen, which was filled with undigested blood. The pancreas was moderately increased in size with an irregular surface and multifocal yellow firm areas. In the cranial portion of the pancreas, a single nodule, approximately 2 cm in diameter, was found. Histologic evaluation of the pancreas revealed chronic and acute lesions characterized by lymphohistiocytic pancreatitis, periductal fibrosis, degeneration of pancreatic islets and necrotizing and fibrinopurulent pancreatitis. The nodule was diagnosed as pancreatic adenocarcinoma. These clinical, imaging, and histopathologic findings were compatible with Hemosuccus pancreaticus. To the authors’ knowledge, this is the first report of Hemosuccus pancreaticusin a dog and it should be considered as a differential diagnosis for dogs with pancreatic disease and gastrointestinal bleeding.

Hemosuccus = pancreaticus in a dog: A rare case of gastrointestinal hemorrhage

A 9-year-old, 5.5-kg (12.12-lb) spayed female Poodle was evaluated due to recurrent seizures and possible diabetes. The dog also had a history of anorexia, polyuria and polydipsia. Serum biochemistry results revealed increases in pancreatic amylase and glucose associated with decreased protein levels. Abdominal ultrasound suggested acute pancreatitis and/or a pancreatic tumor with intense peripancreatic vascularization. The clinical condition of the dog worsened despite medical treatment, and death occurred shortly thereafter. At necropsy, blood clots were found in the stomach and in the intestinal lumen, which was filled with undigested blood. The pancreas was moderately increased in size with an irregular surface and multifocal yellow firm areas. In the cranial portion of the pancreas, a single nodule, approximately 2 cm in diameter, was found. Histologic evaluation of the pancreas revealed chronic and acute lesions characterized by lymphohistiocytic pancreatitis, periductal fibrosis, degeneration of pancreatic islets and necrotizing and fibrinopurulent pancreatitis. The nodule was diagnosed as pancreatic adenocarcinoma. These clinical, imaging, and histopathologic findings were compatible with Hemosuccus pancreaticus. To the authors knowledge, this is the first report of Hemosuccus pancreaticusin a dog and it should be considered as a differential diagnosis for dogs with pancreatic disease and gastrointestinal bleeding.(AU)

Congenital Cerebellar Vermis Aplasia Associated with Hydrocephalus in a Foal

A 2-day-old Mangalarga Marchador colt was presented with clinical signs of severe mental depression, unable to stand, and lacking a suckling reflex. Despite intensive medical care, there was no improvement and the colt died 30 hours later. Gross lesions were characterized by aplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, communicant hydrocephalus involving all ventricles and villous hyperplasia of the choroid plexus in the fourth ventricle. The cerebral parenchyma adjacent to lateral ventricles was markedly reduced. In addition, there was aspiration pneumonia. Aplasia of the cerebellar vermis and cystic dilatation of the fourth ventricle could be compared to the Dandy-Walker-syndrome (DWS). Nevertheless, congenital cerebellar anomalies combined with villous hyperplasia of the choroid plexus in the fourth ventricle and hydrocephalus are describing for the first time in animals, alerting clinicians and pathologists for future investigations about the incidence and etiology of the condition.

Congenital Cerebellar Vermis Aplasia Associated with Hydrocephalus in a Foal

A 2-day-old Mangalarga Marchador colt was presented with clinical signs of severe mental depression, unable to stand, and lacking a suckling reflex. Despite intensive medical care, there was no improvement and the colt died 30 hours later. Gross lesions were characterized by aplasia of the cerebellar vermis, cystic dilatation of the fourth ventricle, communicant hydrocephalus involving all ventricles and villous hyperplasia of the choroid plexus in the fourth ventricle. The cerebral parenchyma adjacent to lateral ventricles was markedly reduced. In addition, there was aspiration pneumonia. Aplasia of the cerebellar vermis and cystic dilatation of the fourth ventricle could be compared to the Dandy-Walker-syndrome (DWS). Nevertheless, congenital cerebellar anomalies combined with villous hyperplasia of the choroid plexus in the fourth ventricle and hydrocephalus are describing for the first time in animals, alerting clinicians and pathologists for future investigations about the incidence and etiology of the condition.(AU)

Asteroid Bodies Associated with Granulomatous Meningoencephalitis in a Female Dog

A case of asteroid bodies associated with granulomatous meningoencephalitis is reported in a 4-year-old female dachshund that showed intermittent tremors and blindness. Necropsy revealed leptomeninges moderately hyperemic and from the parietal cortex extending into the temporal and frontal cortex, thalamus and midbrain flattening of the gyri and a grayish and friable focally extensive area. Microscopically intense and extensive perivascular inflammatory infiltrates of lymphocytes, plasma cells, macrophages and giant cells were observed. In the cytoplasm of the giant cells, neuropil stellate structures ranging from 20 to 80 m in diameter with a central dense and homogenous zone and with amphophilic and vacuolated cytoplasm consistent with asteroid bodies were present. Special staining and transmission electron microscopy permitted the diagnosis of asteroid bodies associated with granulomatous meningoencephalitis.

Asteroid Bodies Associated with Granulomatous Meningoencephalitis in a Female Dog

A case of asteroid bodies associated with granulomatous meningoencephalitis is reported in a 4-year-old female dachshund that showed intermittent tremors and blindness. Necropsy revealed leptomeninges moderately hyperemic and from the parietal cortex extending into the temporal and frontal cortex, thalamus and midbrain flattening of the gyri and a grayish and friable focally extensive area. Microscopically intense and extensive perivascular inflammatory infiltrates of lymphocytes, plasma cells, macrophages and giant cells were observed. In the cytoplasm of the giant cells, neuropil stellate structures ranging from 20 to 80 m in diameter with a central dense and homogenous zone and with amphophilic and vacuolated cytoplasm consistent with asteroid bodies were present. Special staining and transmission electron microscopy permitted the diagnosis of asteroid bodies associated with granulomatous meningoencephalitis.(AU)

Synchronous Multicentric Osteosarcoma in the Canine Axial Skeleton: a Report of Two Cases

Two cases of axial synchronous multicentric osteosarcoma are described in male dogs 11 and 13 years of age. In both cases, the necropsy revealed multiple tumor nodules or masses in the thoracic vertebrae and ribs. The microscopic features indicated that the masses were osteoblastic osteosarcoma for all bone sites with immunohistochemical expression of vimentin and osteocalcin and the absence of cytokeratin. In both cases, multicentric osteosarcoma was considered to be present simultaneously in various bone sites of the axial skeleton, to be of the same histological type and to exhibit the same immunohistochemical characteristics in all bone sites, with no macroscopic or microscopic metastases to the lungs or any other soft tissue.

Synchronous Multicentric Osteosarcoma in the Canine Axial Skeleton: a Report of Two Cases

Two cases of axial synchronous multicentric osteosarcoma are described in male dogs 11 and 13 years of age. In both cases, the necropsy revealed multiple tumor nodules or masses in the thoracic vertebrae and ribs. The microscopic features indicated that the masses were osteoblastic osteosarcoma for all bone sites with immunohistochemical expression of vimentin and osteocalcin and the absence of cytokeratin. In both cases, multicentric osteosarcoma was considered to be present simultaneously in various bone sites of the axial skeleton, to be of the same histological type and to exhibit the same immunohistochemical characteristics in all bone sites, with no macroscopic or microscopic metastases to the lungs or any other soft tissue.(AU)