Retrospective evaluation of canine anal sac carcinoma (260 cases) in Brazil: late detection and failures in lymph node evaluation

Abstract

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.

Exérese de adenocarcinoma de cólon retal e reconstrução do ânus

“…Um estudo retrospectivo brasileiro realizado num período de 12 anos (2010-2021), constatou que apenas 7% dos tumores são diagnosticados com tamanho menor que 2,5 cm e que a média do tamanho do tumor ao diagnóstico foi de 5.4 cm. Paiva et al (2023), destacaram também que metástases foram encontradas em 48.57% dos casos, condizente com o que foi encontrado no caso.…”

“…O uso de doxorrubicina também é bem relatado e, apesar de não ser uma neoplasia responsiva, esse tratamento aumenta as chances de sucesso na associação com a remoção cirúrgica (Cápua et al, 2011;Daleck et al, 2016). Infelizmente seus sintomas só são percebidos em casos mais avançados e podem incluir inapetência, vômitos, apatia, anorexia, diarreia, perda de peso, hematoquesia, tenesmo, dor abdominal (Chaves et al, 2020;Mesquita et al, 2024;Paiva et al, 2023;Requicha et al, 2015) O objetivo desse relato é mostrar a cirurgia de retirada de um grande tumor de saco anal muito infiltrado e com dois focos de metástase nos linfonodos ilíacos.…”