Immunohistochemical Expression of Human Epidermal Growth Factor Receptor 2 and Ki67 in Apocrine Gland Anal Sac Adenocarcinoma.

Apocrine gland anal sac adenocarcinoma is an aggressive neoplasm, and surgery remains the treatment of choice, although it is controversial in advanced cases. The prognostic factors are not well established. Human Epidermal Growth Factor Receptor 2 (HER2) is a membrane protein related to tumorigenesis, whereas Ki67 is a nuclear protein related to cell proliferation. Both are potential prognostic markers and therapeutic targets. This study aimed to evaluate the expression of HER2 and Ki67 markers in canine apocrine gland anal sac adenocarcinoma. The tumor samples were divided into four groups: largest tumor diameter less than 2.5 cm, largest tumor diameter greater than 2.5 cm, metastatic lymph nodes, and control group of non-neoplastic anal sacs. Each contained 10 samples. Immunohistochemistry was performed to verify the expression of HER2 and Ki67 markers. Positive HER2 staining was observed in 45% of the neoplastic cases and negative HER2 staining in 100% of the control group. The Ki67 expression had a median of 25% in all groups, except for the control group, which had a median of 8%. The HER2 and Ki67 expression was present in apocrine gland anal sac adenocarcinoma, making them potential therapeutic targets. However, it was not possible to determine the clinical value of either marker.

Retrospective evaluation of canine anal sac carcinoma (260 cases) in Brazil: late detection and failures in lymph node evaluation / Avaliação retrospectiva do carcinoma de saco anal canino (260 casos) no Brasil: detecção tardia e falhas na avaliação dos linfonodos

Anal sac neoplasms are common in companion animals, and the epidemiological profile has been extensively described in international studies; however, national data are still lacking. Data on the Brazilian reality of anal sac carcinoma cases' diagnosis and treatment are also scarce. The purpose of this study was to retrospectively evaluate cases of canine anal sac carcinoma and assess the profile of involvement, tumor size, and lymphatic invasion at the time of diagnosis. Information was obtained from Vetpat laboratory database, from 260 cases spanning a 12-year period (2010-2021). In histopathological evaluation at the time of diagnosis, data on sex, age, and race were described, as well as tumor size and lymphatic invasion. The presence of metastasis was also assessed in cases where lymph nodes were sampled. Simple descriptive statistical analysis was used to evaluate the data. Adult and elderly, female, and mixed-breed animals were more involved, indicating differences from international studies that can be attributed to sociocultural factors. In terms of tumor size, it was observed that 93% of the cases had the largest diameter above 2.5cm. Only 7% of the cases had the largest diameter below 2.5cm, demonstrating the often late diagnosis and the importance of rectal palpation examination during the general physical assessment of canine patients, particularly at an advanced age. Regarding lymphatic invasion and affected lymph nodes, 50% of the cases had lymphatic invasion described in the histopathological examination. However, only 5% of the lymph nodes were sent along with the primary tumor, indicating the disease's aggressive behavior but with possible metastases underdiagnosed.

As neoplasias de saco anal possuem incidência importante nos animais de companhia, tendo o seu perfil epidemiológico de acometimento amplamente descrito em estudos internacionais, entretanto dados nacionais ainda são escassos. De modo semelhante, dados acerca da realidade brasileira, associados ao diagnóstico e conduta desses casos, são inexistentes. O objetivo do presente trabalho foi avaliar, de forma retrospectiva, os casos de carcinoma de saco anal canino, avaliando o perfil de acometimento, o tamanho tumoral e a invasão linfática no momento do diagnóstico. Foi obtido informações de 260 casos, respectivo a um período de 12 anos (2010-2021), proveniente do banco de dados do laboratório Vetpat. Foram descritos os dados acerca do sexo, idade e raça, bem como o tamanho tumoral e presença de invasão linfática em avaliação histopatológica no momento do diagnóstico. Os casos que cursavam com envio dos linfonodos também foram avaliados quanto a presença de metástase. Os dados foram avaliados mediante análise estatística descritiva simples. Foi encontrado um maior acometimento em animais adultos a idosos, do sexo feminino e sem raça definida, evidenciando diferenças em relação a estudos internacionais, que podem ser atribuídas a fatores socioculturais. Em relação ao tamanho tumoral, observou-se que 93% dos casos apresentavam o maior diâmetro acima de 2,5cm e apenas 7% dos casos apresentavam o maior diâmetro abaixo de 2,5cm, evidenciando o diagnostico frequentemente tardio, bem como a importância do exame de palpação retal durante a avaliação física geral de pacientes caninos, principalmente em idade avançada. Quanto a avaliação da invasão linfática e linfonodos acometidos, 50% dos casos cursavam com invasão linfática descrita em exame histopatológico, entretanto em apenas 5% dos casos os linfonodos foram enviados junto ao tumor primário, evidenciando o comportamento agressivo da doença, porém com metástases possivelmente subdiagnosticadas.

Adenocarcinoma de saco anal com metástase vertebro-medular em um Cocker Spaniel / 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.

Diferencia en la población de células cebadas de glándulas apocrinas de sacos anales de perros adultos y seniles / Difference in the population of mast cells of anal sac apocrine glands of adult and senile dogs

Se estudió la población de células cebadas (CC) presentes en sacos anales de perros adultos y seniles mediante su conteo en cortes de tejido procesado con la técnica de inclusión en parafina y teñidos con azul de toluidina. El promedio de CC obtenido para el grupo de perros adultos jóvenes fue de 18,16 +/- 7,58 (n=12 perros) y para el grupos de adultos maduros fue de 73,75 +/- 16,29 (n=12 perros). Al comparar el número de células de ambos grupos con la prueba de U Mann-Withney se encontró que son significativamente diferentes (P< 0,0001), siendo mayor en el grupo de perros seniles. Esta mayor población de CC puede estar relacionada con una mayor susceptibilidad de los perros seniles a reacciones inflamatorias del tejido de los sacos anales causadas por cambios en la dieta, obesidad y diarrea crónica.

We studied the population of mast cells (CC) present in anal sacs of adult and senile dogs by its count in tissue processed with the technique of embedding in paraffin and stained with toluidine blue. The average CC obtained for the group of adult dogs (n=12) was 18.16 +/- 7.58 and for group of senile dogs (n=12) was 73.75 +/- 16.29. When comparing the number of cells in both groups with Mann-Whitney U test were found to be significantly different (P0.0001), being higher in the group of senile dogs. The largest population of CC may be related to an increased susceptibility of senile dogs to inflammatory reactions in the tissue of the anal sacs caused by changes in diet, obesity and chronic diarrhea.

Estudios macro y microscópico del saco anal del coipo: myocastor coypus / Macro and microscopic studies of the anal sac of the coypus: myocastor coypus

Fue realizada la disección del saco anal de 44 coipos, de ambos sexos, de distintas edades y procedencias, observándose algunas características similares a los sacos anales del perro y gato, aunque es impar y está ubicado en ventral del ano. Es ovoídeo o piriforme, siendo más grande en los adultos y, entre éstos, más aún en los machos que en las hembras; posee un conducto que desemboca en el canal anal a un centímetro del ano y que se exterioriza en el momento de secretar el producto glandular. Se encuentra rodeado de una cápsula de tejido fibroso e insertado en ella se observa tejido muscular estriado, correspondiente a fibras de los músculos del diafragma pelviano. Microscópicamente está constituido por un tejido glandular tubuloalveolar, con células globosas de núcleo laxo, con uno o más nucleolos. Desde la cápsula hacia el interior se forman tabiques de tejido conectivo que dividen al tejido glandular en lóbulos y lobulillos. Mediante coloraciones especiales se constató la presencia de fibras que contienen colágeno de los tipos I y III, de fibras eleunínicas y oxitalánicas

[Natural infection of the anal glands of the opossum (Didelphis albiventris) by Trypanosoma cruzi in the municipality of Bambuí--MG, Brazil]. / Infecção natural das glãndulas anais de gambãs (Didelphis albiventris) pelo Trypanosoma cruzi no municipio de bambui--mg.

Out of 87 opossums, Didelphis albiventris, captured in the Bambuí area (Minas Gerais State), 32 (36.7%) were found infected by Trypanosoma cruzi; the rates varied according to whether the specimens originated from sylvan, rural peridomiciliar or urban surroundings, being 34.9, 81.8 and 7.7 respectively. From 20 of the infected opossums the anal glands were repeatedly examined and found positive in only one (5%) specimen (GA 9), with 7 positive examinations out of 17 performed through an 18-months periods. Material from these glands produced patent parasitemia in opossums and sub-patent infections in mice. Isolates from the opossum GA 9, obtained through xenodiagnoses and hemocultures and from cultures of the infected anal glands fitted into zymodeme Z1.

Trypanosoma cruzi: vertebrate and invertebrate cycles in the same mammal host, the opossum Didelphis marsupialis.

Epimastigotes multiplying extracellularly and metacyclic trypomastigotes, stages that correspond to the cycle of Trypanosoma cruzi in the intestinal lumen of its insect vector, were consistently found in the lumen of the anal glands of opossums Didelphis marsupialis inoculated subcutaneously with infective feces of triatomid bugs.

Trypanosoma cruzi: vertebrate and invertebrate cycles in the same mammal host, the opossum Didelphis marsupialis.

No gamba (Didelphis marsupialis) foi observado um ciclo extracelular do Trypanosoma cruzi: o parasita crescia abundantemente no material de secrecao acumulado no lumen das glandulas anais de animais criados em cativeiro e infectados por via subcutanea com fezes de triatomineos