Anal Sac Adenocarcinoma with Vertebromedullary Metastasis in a Cocker Spaniel

Background: Several neoplasms can affect the perianal region, being the hepatic adenoma and the anal sac adenocarcinoma (ASAC), which is considered the most frequent. The ASAC is a malignant neoplasm originating from the secretory epithelium of the perianal apocrine glands and is rarely seen in veterinary medicine. The ASAC occurs mainly in adult to elderly canines with high metastasis rates. Patients may be asymptomatic or manifest discomfort and behavioral changes. In the presence of metastasis, the most frequent clinical signs are inappetence, coughing, dyspnea, and colorectal obstruction. Given this scenario, this paper aims to describe the clinical presentation, diagnostic examination, and necropsy findings of a Cocker Spaniel with ASAC and metastasis in the vertebral body, spinal cord, and cauda equina. Case: A 8-year-old neutered male Cocker Spaniel (12 kg of body mass) with a clinical history of non-ambulatory paraparesis was evaluated. The patient also presented tenesmus, difficulty to defecate, and the presence of nodules in the anal sac area. On the neurological examination, asymmetrical changes compatible with injury between L4-S3 were found. A complete blood count, serum biochemistry, and imaging exams such as plain radiography, abdominal ultrasonography (US), and magnetic resonance imaging (MRI) were requested. Blood count revealed anemia and neutrophilic leukocytosis and hypercalcemia. The liver showed increased echogenicity and thickened pancreas in the abdominal US scan. A slightly heterogeneous, vascularized mass with irregular borders was identified in the topographic region of the sublumbar lymph nodes; MRI images demonstrated an expansile formation in the ventral region of the lumbosacral spine, corresponding to the sublumbar lymph nodes and interruption of the cerebrospinal fluid at L5, suggestive of compression of the spinal cord and cauda equina. A presumptive diagnosis of perianal neoplasm with metastasis was made based on the complementary exams. The dog was referred to necropsy, which revealed a 4 cm tumor in the perianal region that invaded the pelvic canal. Multifocal nodules were present on the lung surface, liver, and kidneys, suggesting metastasis. On the cross-section of the spine, one could note the presence of the tumor in the vertebral bodies, spinal cord, and cauda equina from L5 to S3. Even with histopathological evaluation of the tumor, only the immunohistochemical analysis allowed us to confirm the anal sac adenocarcinoma. Discussion: Adenomas and carcinomas are perianal gland neoplasms common in adult and elderly male dogs; the Cocker Spaniel breed is among the most affected. The clinical signs presented by the patient, such as tenesmus and difficulty in adopting the posture of defecation, are common, although neurological changes are rare. As for metastasis, carcinomas of the perianal region present high chances of metastasis to organs including the liver, kidneys, and lungs, both lymphatically and hematogenously, but few studies have related these factors to neurological alterations  due to metastasis. We concluded that metastases from carcinomas to the spine must be considered a possible differential diagnosis in cases of patients presenting clinical signs that are compatible with spinal cord compression and a history of previous neoplasm. Keywords: canine perianal carcinoma, neoplasm, spinal cord metastasis. Título: Adenocarcinoma de saco anal com metástase vertebro-medular em um Cocker Spaniel Descritores: carcinoma perianal canino, neoplasma, metástase medula espinhal.Introdução: Diversas neoplasias podem acometer a região perianal, sendo o adenoma hepático e o adenocarcinoma do saco anal (ASA), considerados os mais frequentes. O ASAC é uma neoplasia maligna originada do epitélio secretor das glândulas apócrinas perianais e raramente é visto na medicina veterinária. O ASA ocorre principalmente em cães adultos a idosos com altas taxas de metástase. Os pacientes podem ser assintomáticos ou manifestar desconforto e alterações comportamentais. Na presença de metástase, os sinais clínicos mais frequentes são inapetência, tosse, dispneia e obstrução colorretal. Diante desse cenário, este trabalho tem como objetivo descrever a apresentação clínica, exame diagnóstico e achados de necropsia de um Cocker Spaniel com ASAC e metástase no corpo vertebral, medula espinhal e cauda equina.Caso: Foi avaliado um macho castrado da raça Cocker Spaniel (12 kg de massa corporal) de oito anos de idade com história clínica de paraparesia não deambulatória. A paciente também apresentava tenesmo, dificuldade para defecar e presença de nódulos na região do saco anal. Ao exame neurológico, foram encontradas alterações assimétricas compatíveis com lesão entre L4-S3. Foram solicitados hemograma completo, bioquímica sérica e exames de imagem como radiografia simples, ultrassonografia (US) abdominal e ressonância magnética (RM). O hemograma revelou anemia e leucocitose neutrofílica e hipercalcemia. O fígado mostrou ecogenicidade aumentada e pâncreas espessado na US abdominal. Identificou-se massa pouco heterogênea, vascularizada e de contornos irregulares na região topográfica dos linfonodos sublombares; As imagens de RM demonstraram formação expansiva na região ventral da coluna lombossacral, correspondendo aos linfonodos sublombares e interrupção do líquido cefalorraquidiano em L5, sugestiva de compressão da medula espinhal e cauda equina. O diagnóstico presuntivo de neoplasia perianal com metástase foi feito com base nos exames complementares. A cadela foi encaminhada para necropsia, que revelou tumoração de 4 cm na região perianal que invadia o canal pélvico. Nódulos multifocais estavam presentes na superfície pulmonar, fígado e rins, sugerindo metástase. No corte transversal da coluna, notou-se a presença do tumor nos corpos vertebrais, medula espinhal e cauda equina de L5 a S3. Mesmo com a avaliação histopatológica do tumor, apenas a análise imuno-histoquímica permitiu confirmar o adenocarcinoma do saco anal.Discussão: Adenomas e carcinomas são neoplasias das glândulas perianais comuns em cães machos adultos e idosos; a raça Cocker Spaniel está entre as mais afetadas. Os sinais clínicos apresentados pelo paciente, como tenesmo e dificuldade em adotar a postura de defecar, são comuns, embora alterações neurológicas sejam raras. Quanto à metástase, os carcinomas da região perianal apresentam grandes chances de metástase para órgãos como fígado, rins e pulmões, tanto por via linfática quanto hematogênica, porém poucos estudos relacionam esses fatores às alterações neurológicas decorrentes da metástase. Concluímos que metástases de carcinomas para a coluna devem ser consideradas um possível diagnóstico diferencial em pacientes que apresentam sinais clínicos compatíveis com compressão medular e história de neoplasia prévia

Intradural Disc Extrusion in a Dog

Background: Intervertebral disc extrusion is an important cause of spinal cord dysfunction in dogs. Intradural localization of the extruded disc material is rare, and is generally associated with a traumatic event or with recurrence of disc extrusion at a previously affected site. We report the clinical presentation, diagnostic workup, and treatment of a dog with intradural intervertebral disc extrusion not preceded by a traumatic event.Case:  A 6-year-old male Dachshund was referred for neurological evaluation due to acute onset of hind-end paralysis preceded by claudication of the left hindlimb. The patient had been receiving conservative treatment to no effect. Neurological examination revealed asymmetric non-ambulatory paraparesis, absence of postural reactions and decreased muscle tone in both hindlimbs, a bilaterally diminished patellar reflex, and a hindlimb withdrawal reflex which was normal on the right and greatly diminished to absent on the left. The lower back was tender to epaxial palpation. Plain radiographs of the lumbar spine in the lateral projection showed calcified material within the spinal canal between the third and fourth lumbar vertebrae. Myelography was suggestively abnormal at the same level, with epidural leakage of contrast at L3-L4. Considering the clinical history, breed, age, neurological signs, and radiographic findings, intervertebral disc disease was suspected despite the inconclusive myelography findings. A dorsolateral lumbar hemilaminectomy was performed. Intraoperatively, the diagnosis was confirmed by visualization of a discolored spinal cord and absence of extradural material. The intradural space was accessed via durotomy. A firm, straw-yellow material was seen compressing the spinal cord and removed. Subsequent histopathological examination confirmed that this material consisted of extruded intervertebral disc contents. Postoperatively, the patient underwent physiotherapy and achieved a satisfactory recovery.Discussion: The most common cause of paraparesis in chondrodystrophic dog breeds is intervertebral disc extrusion. Intradural extrusion of the intervertebral disc is a rare phenomenon, often associated with vigorous exercise that causes laceration of the dura mater, allowing penetration of disc material into the intradural space. Although there were no classic signs of intervertebral disc disease on plain radiography, radiopaque material was visible within the spinal canal, which can occur in cases of calcified intervertebral disc extrusion. Myelography was inconclusive, but the decision was made to operate nevertheless, considering that the patient had not responded to conservative treatment and that surgicaltreatment is the most suitable approach for dogs with non-ambulatory paraparesis or paraplegia secondary to intervertebral disc extrusion. The surgical technique consisted of a hemilaminectomy and durotomy. Our diagnostic suspicion was confirmed intraoperatively, as in most cases of intradural disc extrusion in humans. Intradural disc extrusion is anuncommon phenomenon in dogs, and the diagnosis is usually only established intraoperatively. This unusual variant of intravertebral disc disease should be included in the differential diagnosis of spinal cord dysfunction in chondrodystrophic breeds, even in the absence of a history of trauma or preexisting intervertebral disc disease. Clinical treatment appears ineffective in these cases. Conversely, surgical treatment can yield good outcomes, and even functional recovery

Anal Sac Adenocarcinoma with Vertebromedullary Metastasis in a Cocker Spaniel

Background: Several neoplasms can affect the perianal region, being the hepatic adenoma and the anal sac adenocarcinoma (ASAC), which is considered the most frequent. The ASAC is a malignant neoplasm originating from the secretory epithelium of the perianal apocrine glands and is rarely seen in veterinary medicine. The ASAC occurs mainly in adult to elderly canines with high metastasis rates. Patients may be asymptomatic or manifest discomfort and behavioral changes. In the presence of metastasis, the most frequent clinical signs are inappetence, coughing, dyspnea, and colorectal obstruction. Given this scenario, this paper aims to describe the clinical presentation, diagnostic examination, and necropsy findings of a Cocker Spaniel with ASAC and metastasis in the vertebral body, spinal cord, and cauda equina. Case: A 8-year-old neutered male Cocker Spaniel (12 kg of body mass) with a clinical history of non-ambulatory paraparesis was evaluated. The patient also presented tenesmus, difficulty to defecate, and the presence of nodules in the anal sac area. On the neurological examination, asymmetrical changes compatible with injury between L4-S3 were found. A complete blood count, serum biochemistry, and imaging exams such as plain radiography, abdominal ultrasonography (US), and magnetic resonance imaging (MRI) were requested. Blood count revealed anemia and neutrophilic leukocytosis and hypercalcemia. The liver showed increased echogenicity and thickened pancreas in the abdominal US scan. A slightly heterogeneous, vascularized mass with irregular borders was identified in the topographic region of the sublumbar lymph nodes; MRI images demonstrated an expansile formation in the ventral region of the lumbosacral spine, corresponding to the sublumbar lymph nodes and interruption of the cerebrospinal fluid at L5, suggestive of compression of the spinal cord and cauda equina. A presumptive diagnosis of perianal neoplasm with metastasis was made based on the complementary exams. The dog was referred to necropsy, which revealed a 4 cm tumor in the perianal region that invaded the pelvic canal. Multifocal nodules were present on the lung surface, liver, and kidneys, suggesting metastasis. On the cross-section of the spine, one could note the presence of the tumor in the vertebral bodies, spinal cord, and cauda equina from L5 to S3. Even with histopathological evaluation of the tumor, only the immunohistochemical analysis allowed us to confirm the anal sac adenocarcinoma. Discussion: Adenomas and carcinomas are perianal gland neoplasms common in adult and elderly male dogs; the Cocker Spaniel breed is among the most affected. The clinical signs presented by the patient, such as tenesmus and difficulty in adopting the posture of defecation, are common, although neurological changes are rare. As for metastasis, carcinomas of the perianal region present high chances of metastasis to organs including the liver, kidneys, and lungs, both lymphatically and hematogenously, but few studies have related these factors to neurological alterations  due to metastasis. We concluded that metastases from carcinomas to the spine must be considered a possible differential diagnosis in cases of patients presenting clinical signs that are compatible with spinal cord compression and a history of previous neoplasm. Keywords: canine perianal carcinoma, neoplasm, spinal cord metastasis. Título: Adenocarcinoma de saco anal com metástase vertebro-medular em um Cocker Spaniel Descritores: carcinoma perianal canino, neoplasma, metástase medula espinhal.Introdução: Diversas neoplasias podem acometer a região perianal, sendo o adenoma hepático e o adenocarcinoma do saco anal (ASA), considerados os mais frequentes. O ASAC é uma neoplasia maligna originada do epitélio secretor das glândulas apócrinas perianais e raramente é visto na medicina veterinária. O ASA ocorre principalmente em cães adultos a idosos com altas taxas de metástase. Os pacientes podem ser assintomáticos ou manifestar desconforto e alterações comportamentais. Na presença de metástase, os sinais clínicos mais frequentes são inapetência, tosse, dispneia e obstrução colorretal. Diante desse cenário, este trabalho tem como objetivo descrever a apresentação clínica, exame diagnóstico e achados de necropsia de um Cocker Spaniel com ASAC e metástase no corpo vertebral, medula espinhal e cauda equina.Caso: Foi avaliado um macho castrado da raça Cocker Spaniel (12 kg de massa corporal) de oito anos de idade com história clínica de paraparesia não deambulatória. A paciente também apresentava tenesmo, dificuldade para defecar e presença de nódulos na região do saco anal. Ao exame neurológico, foram encontradas alterações assimétricas compatíveis com lesão entre L4-S3. Foram solicitados hemograma completo, bioquímica sérica e exames de imagem como radiografia simples, ultrassonografia (US) abdominal e ressonância magnética (RM). O hemograma revelou anemia e leucocitose neutrofílica e hipercalcemia. O fígado mostrou ecogenicidade aumentada e pâncreas espessado na US abdominal. Identificou-se massa pouco heterogênea, vascularizada e de contornos irregulares na região topográfica dos linfonodos sublombares; As imagens de RM demonstraram formação expansiva na região ventral da coluna lombossacral, correspondendo aos linfonodos sublombares e interrupção do líquido cefalorraquidiano em L5, sugestiva de compressão da medula espinhal e cauda equina. O diagnóstico presuntivo de neoplasia perianal com metástase foi feito com base nos exames complementares. A cadela foi encaminhada para necropsia, que revelou tumoração de 4 cm na região perianal que invadia o canal pélvico. Nódulos multifocais estavam presentes na superfície pulmonar, fígado e rins, sugerindo metástase. No corte transversal da coluna, notou-se a presença do tumor nos corpos vertebrais, medula espinhal e cauda equina de L5 a S3. Mesmo com a avaliação histopatológica do tumor, apenas a análise imuno-histoquímica permitiu confirmar o adenocarcinoma do saco anal.Discussão: Adenomas e carcinomas são neoplasias das glândulas perianais comuns em cães machos adultos e idosos; a raça Cocker Spaniel está entre as mais afetadas. Os sinais clínicos apresentados pelo paciente, como tenesmo e dificuldade em adotar a postura de defecar, são comuns, embora alterações neurológicas sejam raras. Quanto à metástase, os carcinomas da região perianal apresentam grandes chances de metástase para órgãos como fígado, rins e pulmões, tanto por via linfática quanto hematogênica, porém poucos estudos relacionam esses fatores às alterações neurológicas decorrentes da metástase. Concluímos que metástases de carcinomas para a coluna devem ser consideradas um possível diagnóstico diferencial em pacientes que apresentam sinais clínicos compatíveis com compressão medular e história de neoplasia prévia

Intradural Disc Extrusion in a Dog

Background: Intervertebral disc extrusion is an important cause of spinal cord dysfunction in dogs. Intradural localization of the extruded disc material is rare, and is generally associated with a traumatic event or with recurrence of disc extrusion at a previously affected site. We report the clinical presentation, diagnostic workup, and treatment of a dog with intradural intervertebral disc extrusion not preceded by a traumatic event.Case:  A 6-year-old male Dachshund was referred for neurological evaluation due to acute onset of hind-end paralysis preceded by claudication of the left hindlimb. The patient had been receiving conservative treatment to no effect. Neurological examination revealed asymmetric non-ambulatory paraparesis, absence of postural reactions and decreased muscle tone in both hindlimbs, a bilaterally diminished patellar reflex, and a hindlimb withdrawal reflex which was normal on the right and greatly diminished to absent on the left. The lower back was tender to epaxial palpation. Plain radiographs of the lumbar spine in the lateral projection showed calcified material within the spinal canal between the third and fourth lumbar vertebrae. Myelography was suggestively abnormal at the same level, with epidural leakage of contrast at L3-L4. Considering the clinical history, breed, age, neurological signs, and radiographic findings, intervertebral disc disease was suspected despite the inconclusive myelography findings. A dorsolateral lumbar hemilaminectomy was performed. Intraoperatively, the diagnosis was confirmed by visualization of a discolored spinal cord and absence of extradural material. The intradural space was accessed via durotomy. A firm, straw-yellow material was seen compressing the spinal cord and removed. Subsequent histopathological examination confirmed that this material consisted of extruded intervertebral disc contents. Postoperatively, the patient underwent physiotherapy and achieved a satisfactory recovery.Discussion: The most common cause of paraparesis in chondrodystrophic dog breeds is intervertebral disc extrusion. Intradural extrusion of the intervertebral disc is a rare phenomenon, often associated with vigorous exercise that causes laceration of the dura mater, allowing penetration of disc material into the intradural space. Although there were no classic signs of intervertebral disc disease on plain radiography, radiopaque material was visible within the spinal canal, which can occur in cases of calcified intervertebral disc extrusion. Myelography was inconclusive, but the decision was made to operate nevertheless, considering that the patient had not responded to conservative treatment and that surgicaltreatment is the most suitable approach for dogs with non-ambulatory paraparesis or paraplegia secondary to intervertebral disc extrusion. The surgical technique consisted of a hemilaminectomy and durotomy. Our diagnostic suspicion was confirmed intraoperatively, as in most cases of intradural disc extrusion in humans. Intradural disc extrusion is anuncommon phenomenon in dogs, and the diagnosis is usually only established intraoperatively. This unusual variant of intravertebral disc disease should be included in the differential diagnosis of spinal cord dysfunction in chondrodystrophic breeds, even in the absence of a history of trauma or preexisting intervertebral disc disease. Clinical treatment appears ineffective in these cases. Conversely, surgical treatment can yield good outcomes, and even functional recovery

Spinal epidural empyema in a cat with neurological, laboratorial and imaging findings similar to spinal canal lymphoma: Spinal epidural empyema in a cat

Background: Spinal epidural empyema (SEE) is a rare disease in cats that has been described as a cause of severe compressive myelopathy. It is characterized by accumulation of purulent exudate in the form of an abscess in the epidural space. Neurological signs range from spinal hyperesthesia to rapidly progressive paraplegia and may be associated with systemic signs. Spinal lymphoma is the most common neoplasm affecting the central nervous system of cats and can mimic different neoplasms and non-neoplastic diseases, such as SEE. The aim of this study is to report a case of SEE in a cat and highlight the similarities in neurological, laboratory, and imaging findings between this disease and spinal lymphoma.Case: A 8-month-old male neutered mixed-breed cat was referred to the Veterinary Medical Teaching Hospital (HVU) of the UFSM with acute, non-progressive paraplegia. On neurological examination, the patient was paraplegic with no nociception, normal spinal reflexes, increased muscle tone in the pelvic limbs, absence of cutaneous trunci reflex, and spinal hyperesthesia between T13-L1, demonstrating injury in the T3-L3 spinal cord segment. The differential diagnoses included acute spinal cord trauma, neoplasm (lymphoma), and infectious diseases. Hemogram showed lymphocytosis (8062/μL); the biochemical examinations were unremarkable. Tests for antibodies against feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) antigens were negative. Simple radiography, abdominal ultrasonography, and cerebrospinal fluid findings were also normal. Myelography showed left dorsolateral extradural spinal cord compression from T12 to L1. Based on these findings, the presumptive diagnosis was spinal lymphoma and chemotherapy was initiated. After 2 days, the animal began to show hyporexia, adipsia, vomiting, and diarrhea, in addition to an increase in subcutaneous volume in the thoracolumbar region. Antibiotic therapy was initiated; however, the patient died. Necropsy revealed an abscess in the left dorsolateral extradural space at T12-T13 and T13-L1. Bacterial cultures revealed the presence of Neisseria spp. that was resistant to various antibiotics. On the basis of these findings, the animal was diagnosed with SEE.Discussion: This case report aims to inform veterinarians about the diagnosis of SEE. SEE is a rare condition in cats compared to spinal lymphoma; however, their presentation is similar. Even in imaging examinations, such as magnetic resonance imaging, it is not possible to differentiate between these 2 conditions. The evolution of clinical signs made the diagnosis of the present case difficult since it was acute and not progressive. All cases of SEE reported in the literature were progressive, acute, or chronic. Although testing for FeLV was negative, only 56% of cats with spinal lymphoma test positive for this virus. Clinical signs reported by the owner after the start of chemotherapy may be related to adverse effects, such as immunosuppression, which led to worsening of the condition, culminating in the appearance of a subcutaneous abscess. Subsequently, SEE was suspected; however, surgical decompression was not performed as the animal died soon after. The authors of this report reinforce the need for a definitive and non-presumptive diagnosis of spinal lymphoma to initiate chemotherapy because it mimics different neoplasms and non-neoplastic diseases, such as SEE. Surgical removal of the compressive mass in the spinal cord and histopathological analyses are necessary. Keywords: SEE, feline, compressive myelopathy, spinal cord, neoplasm, neurological signs. Título: Empiema epidural espinhal em gato com suspeita de linfoma em canal vertebral Descritores: EEE, felino, mielopatia compressiva, canal vertebral, neoplasma, sinais neurológicos.O empiema epidural espinhal (EEE) é uma doença rara em gatos que tem sido descrita como causa de mielopatia compressiva grave. Caracteriza-se pelo acúmulo de exsudato purulento na forma de abscesso no espaço epidural. Os sinais neurológicos variam de hiperestesia espinhal a paraplegia rapidamente progressiva e podem estar associados a sinais sistêmicos. O linfoma espinhal é a neoplasia mais comum que acomete o sistema nervoso central de gatos e pode mimetizar diversas neoplasias e doenças não neoplásicas, como a EEE. O objetivo deste estudo é relatar um caso de SEE em um gato e destacar as semelhanças nos achados neurológicos, laboratoriais e de imagem entre esta doença e o linfoma espinhal. Um gato mestiço de 8 meses de idade, castrado, apresentou paraplegia aguda não progressiva. Ao exame neurológico, o paciente estava paraplégico, sem nocicepção, reflexos espinhais normais, tônus muscular aumentado nos membros pélvicos, ausência de reflexo cutâneo do tronco e hiperestesia espinhal entre T13-L1, demonstrando lesão no segmento medular T3-L3. Os diagnósticos diferenciais incluíram trauma agudo da medula espinhal, neoplasia (linfoma) e doenças infecciosas. O hemograma mostrou linfocitose (8062/μL); os exames bioquímicos foram normais. Os testes de anticorpos contra os antígenos do vírus da imunodeficiência felina (FIV) e do vírus da leucemia felina (FeLV) foram negativos. Radiografia simples, ultrassonografia abdominal e achados de líquido cefalorraquidiano também foram normais. A mielografia mostrou compressão medular extradural dorsolateral esquerda de T12 a L1. Com base nesses achados, o diagnóstico presuntivo foi de linfoma espinhal e foi iniciada quimioterapia. Após dois dias, o animal começou a apresentar hiporexia, adipsia, vômitos e diarreia, além de aumento do volume subcutâneo na região toracolombar. A antibioticoterapia foi iniciada; no entanto, o paciente morreu. A necropsia revelou um abscesso no espaço extradural dorsolateral esquerdo em T12-T13 e T13-L1. As culturas bacterianas revelaram a presença de Neisseria spp. que era resistente a vários antibióticos. Com base nesses achados, o animal foi diagnosticado com EEE. Este relato de caso tem como objetivo informar os médicos veterinários sobre o diagnóstico de SEE. SEE é uma condição rara em gatos em comparação com o linfoma espinhal; no entanto, sua apresentação é semelhante. Mesmo em exames de imagem, como a ressonância magnética, não é possível diferenciar essas duas condições. A evolução dos sinais clínicos dificultou o diagnóstico do presente caso por ser agudo e não progressivo. Todos os casos de EEE relatados na literatura foram progressivos, agudos ou crônicos. Embora o teste para FeLV tenha sido negativo, apenas 56% dos gatos com linfoma espinhal testam positivo para este vírus. Os sinais clínicos relatados pelo proprietário após o início da quimioterapia podem estar relacionados a efeitos adversos, como imunossupressão, o que levou ao agravamento do quadro, culminando com o aparecimento de um abscesso subcutâneo. Posteriormente, houve suspeita de SEE; no entanto, a descompressão cirúrgica não foi realizada, pois o animal veio a falecer logo em seguida. Os autores deste relato reforçam a necessidade de um diagnóstico definitivo e não presuntivo de linfoma espinhal para iniciar a quimioterapia, pois mimetiza diferentes neoplasias e doenças não neoplásicas, como o EEE. A remoção cirúrgica da massa compressiva na medula espinhal e análises histopatológicas são necessárias. Os autores deste relato reforçam a necessidade de um diagnóstico definitivo e não presuntivo de linfoma espinhal para iniciar a quimioterapia, pois mimetiza diferentes neoplasias e doenças não neoplásicas, como o EEE. A remoção cirúrgica da massa compressiva na medula espinhal e análises histopatológicas são necessárias. Os autores deste relato reforçam a necessidade de um diagnóstico definitivo e não presuntivo de linfoma espinhal para iniciar a quimioterapia, pois mimetiza diferentes neoplasias e doenças não neoplásicas, como o EEE. A remoção cirúrgica da massa compressiva na medula espinhal e análises histopatológicas são necessária

Spinal epidural empyema in a cat with neurological, laboratorial and imaging findings similar to spinal canal lymphoma: Spinal epidural empyema in a cat

Background: Spinal epidural empyema (SEE) is a rare disease in cats that has been described as a cause of severe compressive myelopathy. It is characterized by accumulation of purulent exudate in the form of an abscess in the epidural space. Neurological signs range from spinal hyperesthesia to rapidly progressive paraplegia and may be associated with systemic signs. Spinal lymphoma is the most common neoplasm affecting the central nervous system of cats and can mimic different neoplasms and non-neoplastic diseases, such as SEE. The aim of this study is to report a case of SEE in a cat and highlight the similarities in neurological, laboratory, and imaging findings between this disease and spinal lymphoma.Case: A 8-month-old male neutered mixed-breed cat was referred to the Veterinary Medical Teaching Hospital (HVU) of the UFSM with acute, non-progressive paraplegia. On neurological examination, the patient was paraplegic with no nociception, normal spinal reflexes, increased muscle tone in the pelvic limbs, absence of cutaneous trunci reflex, and spinal hyperesthesia between T13-L1, demonstrating injury in the T3-L3 spinal cord segment. The differential diagnoses included acute spinal cord trauma, neoplasm (lymphoma), and infectious diseases. Hemogram showed lymphocytosis (8062/μL); the biochemical examinations were unremarkable. Tests for antibodies against feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) antigens were negative. Simple radiography, abdominal ultrasonography, and cerebrospinal fluid findings were also normal. Myelography showed left dorsolateral extradural spinal cord compression from T12 to L1. Based on these findings, the presumptive diagnosis was spinal lymphoma and chemotherapy was initiated. After 2 days, the animal began to show hyporexia, adipsia, vomiting, and diarrhea, in addition to an increase in subcutaneous volume in the thoracolumbar region. Antibiotic therapy was initiated; however, the patient died. Necropsy revealed an abscess in the left dorsolateral extradural space at T12-T13 and T13-L1. Bacterial cultures revealed the presence of Neisseria spp. that was resistant to various antibiotics. On the basis of these findings, the animal was diagnosed with SEE.Discussion: This case report aims to inform veterinarians about the diagnosis of SEE. SEE is a rare condition in cats compared to spinal lymphoma; however, their presentation is similar. Even in imaging examinations, such as magnetic resonance imaging, it is not possible to differentiate between these 2 conditions. The evolution of clinical signs made the diagnosis of the present case difficult since it was acute and not progressive. All cases of SEE reported in the literature were progressive, acute, or chronic. Although testing for FeLV was negative, only 56% of cats with spinal lymphoma test positive for this virus. Clinical signs reported by the owner after the start of chemotherapy may be related to adverse effects, such as immunosuppression, which led to worsening of the condition, culminating in the appearance of a subcutaneous abscess. Subsequently, SEE was suspected; however, surgical decompression was not performed as the animal died soon after. The authors of this report reinforce the need for a definitive and non-presumptive diagnosis of spinal lymphoma to initiate chemotherapy because it mimics different neoplasms and non-neoplastic diseases, such as SEE. Surgical removal of the compressive mass in the spinal cord and histopathological analyses are necessary. Keywords: SEE, feline, compressive myelopathy, spinal cord, neoplasm, neurological signs. Título: Empiema epidural espinhal em gato com suspeita de linfoma em canal vertebral Descritores: EEE, felino, mielopatia compressiva, canal vertebral, neoplasma, sinais neurológicos.O empiema epidural espinhal (EEE) é uma doença rara em gatos que tem sido descrita como causa de mielopatia compressiva grave. Caracteriza-se pelo acúmulo de exsudato purulento na forma de abscesso no espaço epidural. Os sinais neurológicos variam de hiperestesia espinhal a paraplegia rapidamente progressiva e podem estar associados a sinais sistêmicos. O linfoma espinhal é a neoplasia mais comum que acomete o sistema nervoso central de gatos e pode mimetizar diversas neoplasias e doenças não neoplásicas, como a EEE. O objetivo deste estudo é relatar um caso de SEE em um gato e destacar as semelhanças nos achados neurológicos, laboratoriais e de imagem entre esta doença e o linfoma espinhal. Um gato mestiço de 8 meses de idade, castrado, apresentou paraplegia aguda não progressiva. Ao exame neurológico, o paciente estava paraplégico, sem nocicepção, reflexos espinhais normais, tônus muscular aumentado nos membros pélvicos, ausência de reflexo cutâneo do tronco e hiperestesia espinhal entre T13-L1, demonstrando lesão no segmento medular T3-L3. Os diagnósticos diferenciais incluíram trauma agudo da medula espinhal, neoplasia (linfoma) e doenças infecciosas. O hemograma mostrou linfocitose (8062/μL); os exames bioquímicos foram normais. Os testes de anticorpos contra os antígenos do vírus da imunodeficiência felina (FIV) e do vírus da leucemia felina (FeLV) foram negativos. Radiografia simples, ultrassonografia abdominal e achados de líquido cefalorraquidiano também foram normais. A mielografia mostrou compressão medular extradural dorsolateral esquerda de T12 a L1. Com base nesses achados, o diagnóstico presuntivo foi de linfoma espinhal e foi iniciada quimioterapia. Após dois dias, o animal começou a apresentar hiporexia, adipsia, vômitos e diarreia, além de aumento do volume subcutâneo na região toracolombar. A antibioticoterapia foi iniciada; no entanto, o paciente morreu. A necropsia revelou um abscesso no espaço extradural dorsolateral esquerdo em T12-T13 e T13-L1. As culturas bacterianas revelaram a presença de Neisseria spp. que era resistente a vários antibióticos. Com base nesses achados, o animal foi diagnosticado com EEE. Este relato de caso tem como objetivo informar os médicos veterinários sobre o diagnóstico de SEE. SEE é uma condição rara em gatos em comparação com o linfoma espinhal; no entanto, sua apresentação é semelhante. Mesmo em exames de imagem, como a ressonância magnética, não é possível diferenciar essas duas condições. A evolução dos sinais clínicos dificultou o diagnóstico do presente caso por ser agudo e não progressivo. Todos os casos de EEE relatados na literatura foram progressivos, agudos ou crônicos. Embora o teste para FeLV tenha sido negativo, apenas 56% dos gatos com linfoma espinhal testam positivo para este vírus. Os sinais clínicos relatados pelo proprietário após o início da quimioterapia podem estar relacionados a efeitos adversos, como imunossupressão, o que levou ao agravamento do quadro, culminando com o aparecimento de um abscesso subcutâneo. Posteriormente, houve suspeita de SEE; no entanto, a descompressão cirúrgica não foi realizada, pois o animal veio a falecer logo em seguida. Os autores deste relato reforçam a necessidade de um diagnóstico definitivo e não presuntivo de linfoma espinhal para iniciar a quimioterapia, pois mimetiza diferentes neoplasias e doenças não neoplásicas, como o EEE. A remoção cirúrgica da massa compressiva na medula espinhal e análises histopatológicas são necessárias. Os autores deste relato reforçam a necessidade de um diagnóstico definitivo e não presuntivo de linfoma espinhal para iniciar a quimioterapia, pois mimetiza diferentes neoplasias e doenças não neoplásicas, como o EEE. A remoção cirúrgica da massa compressiva na medula espinhal e análises histopatológicas são necessárias. Os autores deste relato reforçam a necessidade de um diagnóstico definitivo e não presuntivo de linfoma espinhal para iniciar a quimioterapia, pois mimetiza diferentes neoplasias e doenças não neoplásicas, como o EEE. A remoção cirúrgica da massa compressiva na medula espinhal e análises histopatológicas são necessária