Anal sac adenocarcinoma in dogs: what's new?

摘要

Anal sac adenocarcinoma is a malignant neoplasm originating from the apocrine glands of the anal sac. Anal sac adenocarcinoma is a locally invasive cancer, with a high rate of metastasis to the regional sublumbar lymph nodes (~50%), and occasionally to the abdominal organs and lungs. Hypercalcaemia of malignancy may be identified as a paraneoplastic syndrome in up to 50% of cases. Anal sac adenocarcinoma is most commonly diagnosed in older dogs (median age 10 years), with Spaniel breeds predisposed.Anal sac masses may be identified as an incidental finding on rectal examination at routine health check, or a patient may present with clinical signs associated with a space-occupying lesion at the anus or due to enlarged sublumbar lymph nodes (constipation/obstipation, dyschezia, tenesmus or ribbonlike stools). Occasionally the presenting complaint is polyuria/polydipsia, anorexia or lethargy, secondary to hypercalcaemia of malignancy.