Plasma cell tumors develop as a result of dysregulated production of plasma cells and are relatively uncommon in dogs and cats. Some plasma cell tumors are benign and are typically confined to the skin or oral cavity, and most are very treatable. Surgical excision is the treatment of choice for removal of benign plasma cell tumors, with little to no recurrence if completely excised. Conversely, multiple myeloma is an aggressive cancer that is usually treated with chemotherapy.
The definition of a pneumothorax is an accumulation of air outside the lungs, but inside the chest wall. The air outside the lung prevents the lungs from inflating normally, and can lead to lung collapse. There are several variations of pneumothorax.
Tumors of the prostate are relatively uncommon in dogs and extremely rare in cats. The most common tumor is prostatic adenocarcinoma. Clinical signs include blood in the urine, changes in urination habits, or straining to urinate or defecate. Metastasis to the pelvic bone and/or lumbar spine is likely. FNA of the prostate aids in the diagnosis, though surgical biopsy may need to be considered. Treatment is limited. Stents may be placed in patients with tumors obstructing the urethra. Radiation therapy in conjunction with NSAID therapy has shown significant survival advantage when compared to pets who did not receive NSAID therapy. The role and/or benefit of chemotherapy is not well understood.
Radiation therapy is the medical use of high dose radiation to destroy cancer cells by damaging the cells’ DNA to interfere with cell replication and kill them. It may be used on its own or in combination with other treatments, such as surgery or chemotherapy, or to reduce the size of very large tumors prior to surgery. There are several radiation protocols used in veterinary medicine. Your veterinary oncologist will choose the therapy most appropriate for your pet’s individual situation.
Round cell tumors are among the most common skin tumors in dogs, and they typically form just under the skin, although they may change the surface of the skin above them. When caught early, most round cell tumors are removed easily, and surgery is generally curative. The most important take home message is to be vigilant, and to have any skin lumps or bumps assessed by your veterinarian promptly.
Salivary gland tumors are rare in dogs and cats. The mandibular and parotid glands are most commonly affected. Older dogs and cats, Poodle and Spaniel breed dogs and Siamese breed cats, and male cats are at a higher risk for salivary gland tumors. The most commonly reported salivary gland tumor is the adenocarcinoma. Signs include swelling of the upper neck or ear base, halitosis, anorexia, weight loss, difficulty eating, pain, and lethargy. Fine needle aspiration may be used to differentiate between neoplastic and non-neoplastic masses. Biopsy provides a definitive diagnosis. General staging as well as CT scan or MRI are recommended since these tumors have a tendency to be locally invasive and metastasize. The treatment of choice is usually surgical excision. If complete excision is not possible, adjunct radiation therapy may be pursued.
Soft tissue sarcomas are a broad category of tumor types. These tumors can arise anywhere there is soft tissue, including the limbs, joints, face, intestine and reproductive tissues. Routine staging is recommended to help dictate therapy. If surgery is possible, wide-surgical excision is pursued. If removal is incomplete or not possible, adjunct radiation therapy can be pursued. Metronomic chemotherapy may provide benefit in patients when few options exist.
Squamous cell carcinoma (SCC) is a tumor of the cells that make up the contact or upper layer of the skin. UV light exposure has been described as a developmental factor in people and appears to be associated with the development in cats. Areas affected include the ear tips, skin, toes, or peri-ocular region. Fine needle aspiration or biopsy may be performed for diagnosis. The metastatic rate does not appear overly clear, though staging is always recommended. SCC of the toe can occur as a primary tumor or may have spread from the lung (lung-digit syndrome). Surgery is almost always recommended in any case of SCC; the role of chemotherapy is controversial. Radiation therapy has an excellent response rate in cats with the SCC affecting the nasal planum and may give long-term tumor control.
Squamous cell carcinoma (SCC) is a tumor of the cells that make up the contact or upper layer of the skin. UV light exposure has been described as a developmental factor in people, though it is still in question as to the role for dogs. Several breeds are known to be predisposed to this type of cancer. This tumor may affect any area of the skin, the nose/nasal planum, or the toes. Fine needle aspiration or biopsy may be performed for diagnosis. About 30% of dogs with the digital form of the disease will have evidence of spread. Regardless of the location, surgery is typically the treatment of choice, and staging is usually recommended prior to any surgery. The role of chemotherapy remains controversial.
Stomach tumors are uncommon in dogs and cats. There are many kinds, including leiomyosarcomas, lymphomas, adenocarcinomas, mast cell tumors, fibrosarcomas, plasmacytomas, gastrointestinal stromal tumors (GISTs), and carcinoids (all malignant); and leiomyomas, adenomatous polyps, and adenomas (benign). Most tumors are malignant. Stomach tumors are more prevalent in older animals, males, and certain breeds. The signs of stomach tumors include chronic vomiting, inappetence, lethargy, and weight loss. Sometimes tumor ulceration will cause anemia. Paraneoplastic syndromes are possible with the muscle tumors. Stomach tumors may be diagnosed with imaging, endoscopy, or surgery, with a biopsy. Treatment may involve surgery, chemotherapy, or radiation therapy.