Anal sac adenocarcinoma is an uncommon condition affecting older dogs that can cause tumors to grow on the anal sacs. Tumors of the anal sac are uncommon and represent a small percentage of all skin tumors in dogs ( 2). The most common malignant tumor of the perianal region is the anal sac (gland) carcinoma, accounting for 15 to 20 of all perianal tumors. These tumors are locally invasive and metastasize early in the course of disease. Anal glands are located on either side of the anus and normally produce secretions that are pushed when feces is evacuated from the rectum. An anal sac tumor is a tumor of made up of cells originating from the glands of the anal sac. These tumors can spread and therefore staging is recommended prior to surgery. To diagnose these tumors, a fine needle aspirate can be placed from the outside and. Canine apocrine gland anal sac adenocarcinoma (agasaca) apocrine gland anal sac adenocarcinomas (agasaca) are malignant tumors of the anal glands. These are paired glands located on either side of the rectal opening. Anal glands are sweat glands that contain a brown, malodorous liquid that is eliminated upon defecation. Anal sac tumours (carcinoma of the apocrine glands of the anal sac) what are anal sac tumours? The anal sacs are two small glands that sit either side of the anus (back passage) under the tail. They produce a strong-smelling secretion which is emptied onto the faeces (stools). Tumours (growths) may develop from the lining cells of these glands. Anal gland adenocarcinoma (aga) (also known as apocrine gland anal sac carcinoma adenocarcinoma or anal sac adenocarcinoma) is an uncommon cancer that arises from the apocrine glands in the walls of the anal sacs. Anal sac mass may be small and hypercalcemia or metastasis may be detected prior to anal sac mass paraneoplastic hypercalcemia. The anal sacs are a pair of scent glands located along each side of the anus. The secretion from the glands is foul-smelling and excreted in small amounts on the feces during bowel movements to mark a pets territory.