An anal sac adenocarcinoma is an unusual and aggressive malignant tumor found in dogs that emerge from the apocrine gland tissue of the anal sac. This disease is present in cats as well, but much more rarely in that species. They are the second most common cause of cancer hypercalcemia (high serum calcium) in dogs, after T cell lymphoma.
Video Anal sac adenocarcinoma
Signs and symptoms
The anal adenocarcinoma sac of the Apocrine gland gland first appears as a small lump associated with one of the rectal sacs (rarely bilateral), but can grow into a large size. Smaller tumors are undetectable without rectal examination, while larger tumors can cause pain and attempt to defecate. Between 25 and 40 percent of dogs with these tumors will also develop hypercalcaemia through secretion of parathyroid hormone-related proteins by tumors. Symptoms of hypercalcaemia include increased drinking and urination, vomiting, loss of appetite, weight loss, and bradycardia (slow heartbeat). The adenocarcinoma sac of the apocrine gland sac also has a tendency to metastasize to regional lymph nodes, spleen, and ultimately the lungs and, more rarely, bone. The sublumbar lymph nodes (iliac) are the most common metastatic sites and can become larger than the original tumor.
Maps Anal sac adenocarcinoma
Diagnosis
Rectal adenocarcinoma pouches are often suspected due to location (palpable mass in the rectal sac) and behavior, but biopsy and histopathology are required for definitive diagnosis. The aspiration of fine needles and cytology is a common first step. Cytopathology reveals a group of cells with a uniform spherical nucleus. These cells do not have many features that are usually associated with malignancy, such as the ratio of the nucleus to the high cytoplasm or prominent nucleolus. Ultrasonography and radiography are performed to look for metastasis.
Treatment and prognosis
Aggressive surgical removal surgery and enlarged sublumbar lymph nodes are essential for the treatment of tumors and associated hypercalcemia. There is a high rate of recurrence, although removal of lymph nodes by metastasis can improve survival time. Radiation therapy and chemotherapy may be helpful in the treatment. Severe hypercalcaemia is treated with aggressive IV fluid therapy using sodium chloride and drugs such as loop diuretics (increased calcium renal excretion) and aminobisfosphonate (decreased calcium release from bone). The worse prognosis is associated with large tumor size (greater than 10 cm), hypercalcaemia, and distan metastasis. Initially, the incidental diagnosis of a small anal pocket mass may lead to better prognosis by surgery alone (ongoing studies).
Breeds that are usually affected
Breeds that may be more commonly affected include British Cocker Spaniel, German Shepherd Dog, Alaskan Malamute, Dachshund, and Springer Spaniel. It is a middle-aged dog disease to older dogs and although early reports describe women spayed as more commonly affected, several recent studies show no overreacting gender.
References
External links
- Anal Dog Tumor Cats and Dogs from Pet Cancer Center
- Anal rectal gland carcinoma: veterinary fact sheet from Davies Veterinary Specialist
- Bladder and Prostate Cancer: Neutering Male Dogs Increase Risk from Dog Cancer Blog
Source of the article : Wikipedia
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