What Is A Soft Tissue Sarcoma
Soft tissue sarcomas are a broad category of tumors including those that arise from the connective, muscle, or nervous tissues in dogs and cats. These tumors are the result of abnormal production of these cell types in an uncontrolled manner. Connective, muscle, and nervous tissues are present throughout the entire body therefore, these tumors can develop over the chest, back, side, legs, and facial tissues of your pet.
Soft tissue sarcomas make up about 15% of cancers of the skin affecting dogs and about 7% of those affecting cats. Fibrosarcomas are common in dogs and are a type of soft tissue sarcoma .
“Soft tissue sarcomas make up about 15% of cancers of the skin affecting dogs and about 7% of those affecting cats.”
Even though soft tissue tumors arise from many different types of cells, they all behave in a similar manner and their treatment is typically the same.
How Are They Treated
Surgical removal of soft tissue sarcomas in the mainstay intervention. The resected tumor tissue should always be submitted for evaluation by a board-certified veterinary pathologist. As one of my surgical professors used to say about tumors
If its worth taking off, its worth finding out what it is!
A pathologist will thoroughly evaluate the tumor, particularly grade, mitotic index, and margins. Grade impacts risk of metastasis and recurrence. Grade 1 and 2 soft tissue sarcomas have low metastatic potential and grade III tumors have high metastatic potential . Mitotic index is predictive of survival. To maximize the likelihood of a positive outcome, soft tissue sarcomas should be widely and deeply resected to achieve clean margins. This means all tumor cells were successfully removed a process that can be much easier said than done. If clean margins are achieved, then no further treatment may be needed. If clean margins werent obtained, then a second surgery may be recommended. Consultation with a board-certified veterinary surgeon may be helpful.
What Is Soft Tissue Sarcoma
A soft tissue sarcoma is a cancer of connective tissue in the body. Connective tissue is the building block of the skeleton and includes tissues such as muscle, bone, tendon, ligament, blood vessels, nerves and the fibrous glue that holds all of these together. It includes the legs, body wall, pelvis, rib cage, and the scaffold of the head and neck.
Sarcomas are classified according to their parent tissue, e.g. osteosarcoma is a tissue of bone, fibrosarcoma is a tumour of fibrous tissue, haemangiosarcoma is a tumour of blood vessel walls, and synovial cell sarcoma is a tumour of synovium, or joint tissue.
Many sarcomas, especially those growing just under the skin , are classified by oncologists as one large group, called soft tissue sarcomas, because despite having subtly different parent tissues, they behave in a very similar fashion in terms of growth, spread and response to treatment.
Sarcomas are typically further classified into grades 1, 2 or 3. This is determined by the appearance of the cancer under the microscope. The pathologist examining the tissue is looking for features such as how rapidly the cells are dividing, how well organised or disorganised they appear in the sample, and whether there is any evidence of cancer cells growing into or occupying tiny blood vessels in the mass, as this can be linked with a higher chance of spread, now or in the future.
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Soft Tissue Sarcoma In Dogs And Cats
Spindle cell sarcomas are also known as soft tissue sarcomas and in general, this term acts as an umbrella for a variety of tumors including . These tumors range in their behavior based upon their cell of origin as well as their grade, which correlates to the aggressiveness of the tumor. Most tend to be low to moderate grade but exceptions exist. These tumors often grow slowly and grow passively along tissue planes. The rate of metastasis depends on the grade of the tumor with low and intermediate grade tumors metastasizing in < 20% of dogs whereas high-grade tumors metastasize in 40-50% of dogs.
STS are often first noted as a lump by the owners that often grow slowly over time. Most often the mass feels fixed to the underlying tissue and its borders are indistinct. The best description of these tumors is an octopus in which the head of the octopus is the area of the tumor you can feel but the tumor has tentacles that can go much deeper out into the surrounding normal tissue. The tendrils of the tumor are actually microscopic cells that are the most active part of the tumor and lead to re-growth when not surgically removed. Patients are staged with chest x-rays, blood work , and abdominal ultrasound . These tests allow us to determine if the cancer has spread to other areas in the body, which is dependent on the type/grade of the tumor.
Peripheral Nerve Sheath Tumors
Amputation neuromas are non-neoplastic, disorganized proliferations of peripheral nerve parenchyma and stroma that form in response to amputation or traumatic injury. They are most commonly identified after tail docking in dogs or neurectomy in the distal extremities of horses. The most common clinical presentation is a young dog that continuously traumatizes its docked tail. In horses, such a lesion appears as a firm, often painful swelling at a neurectomy surgery site. Excision is curative.
Neurofibromas and neurofibrosarcomas are spindle-cell tumors that arise from the connective tissue components of the peripheral nerve. They are believed to arise from Schwann cells, but they could also arise from mesenchymal cells, which produce the nonmyelinated connective tissues that surround the myelinated nerve fiber. In dogs, forms of this tumor can be virtually indistinguishable from hemangiopericytomas and may be the same tumor.
In dogs and cats, peripheral nerve sheath tumors of the skin are found in older animals. In cattle, they have a suspected genetic basis, may be multiple, can develop in both the young and old, and are generally an incidental finding at slaughter they arise from the deep nerves of the thoracic wall and viscera, and cutaneous involvement is rare. Regardless of species, these tumors appear as white, firm, nodules. Attachment to a peripheral nerve may occasionally be noted.
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How Are Soft Tissue Sarcomas Diagnosed
In some cases, a fine needle aspiration may be performed. FNA involves taking a small needle with a syringe to suction a sample of cells directly from the tumor and placing them on a microscope slide. A veterinary pathologist then examines the slide under a microscope. If a diagnosis is not confirmed by this method, a biopsy may be needed. A biopsy is a surgical excision of a piece of the tumor. Pieces of the tumor are then examined under the microscope. This is called histopathology. A biopsy is beneficial because it gives an indication as to how aggressive the tumor is and how its treatment should be approached.
Staging may be recommended. This may include blood work, urinalysis, radiographs of the lungs, and possibly an abdominal ultrasound. If any lymph nodes are enlarged or feel abnormal, further sampling may be pursued to determine if any spread is present.
“If any lymph nodes are enlarged or feel abnormal, further sampling may be pursued to determine if any spread is present.”
Diagnosis Of Feline Fibrosarcoma
Due to the possibility of fibrosarcoma in cats, the injection site needs to be monitored in the weeks following vaccination administration. If an abscess at the injection site appears, an ultrasound scan needs to be carried out as part of a differential diagnosis. Feline leukemia virus infection also needs to be tested for.
Cytology is of little use in diagnosis of fibrosarcoma in cats. If it is carried out, it will require a wedge biopsy and pathological study. This biopsy will usually only be performed in the presence of lumps more than 2 cm in width and in those which have been present three months after inoculation or have grown significantly after 1 month.
The histology of the biopsy will test for the important inflammatory component. it will also look for the proliferation of mononuclear cells, fibrosis and granulation. These types of soft tissue sarcoma in cats are characterized by high cellular mitosis and frequent central necrosis . X-rays of the chest should also be carried out to assess whether metastasis has occurred in the lung or other areas.
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Soft Tissue Sarcomas In Cats & Dogs
Unfortunately our feline and canine companions are susceptible to cancers just like we humans. In previous posts, Ive shared information about some common cancers in cats and dogs, including mast cell tumors, malignant melanoma, mammary tumors, and urinary bladder cancer. This week I wanted to provide some facts about a group of cancers collectively called soft tissue sarcomas. I hope you find the information helpful and shareworthy. Happy reading!
Diagnosing Cancer In Cats
Veterinarians rely on many of the same diagnostic tools used in human medicine, including blood work, radiographs, ultrasounds, MRIs, cat scans and pet scans.
Cells can be obtained by aspirating a mass or tumor with a needleor evaluating whole blood in the case of leukemiaand analyzed by cytology, which is a microscopic cell analysis, says Dr. Lachowicz.
Aspiration can be performed on masses that are at the skin level, under the skin or in internal organs, as long as the mass is easy to reach with a long needle. Usually these aspirations are performed with an abdominal ultrasound by a trained veterinarian to avoid internal injury.
Alternatively, or in addition to cytology, a tissue sample may be obtained surgically for histopathology , says Dr. Lachowicz.
Biopsy usually requires sedation and requires a much larger tissue sample for evaluation.
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Prevention Of Fibrosarcoma In Cats
The incidence of this disease in cats increases the more they are vaccinated. However, the incidence of diseases and their fatal consequences prevented by vaccination are much high than the risk of a fibrosarcoma tumor developing. For this reason, a suitable vaccination schedule is recommended for all cats.
To prevent difficulty in removing a tumor in the interscapular area, it is sometimes recommended cats are vaccinated in other areas. These include the extremities or the area behind the cat’s ribs. If the tumor does appear at the vaccination site of a limb, the limb can be amputated or a better extirpation can be achieved within the necessary surgical margins.
This article is purely informative. AnimalWised does not have the authority to prescribe any veterinary treatment or create a diagnosis. We invite you to take your pet to the veterinarian if they are suffering from any condition or pain.
If you want to read similar articles to Fibrosarcoma in Cats – Causes, Symptoms and Treatment, we recommend you visit our Other health problems category.
Symptoms Of Soft Tissue Sarcoma In Dogs And Cats
STS is usually spotted as a solid mass found on your pets limbs, oral cavity, or trunk. The symptoms will depend on the severity and location of the growth.
A mass in the gastrointestinal tract often causes diarrhea, weight loss, or vomiting. When found somewhere in the mouth, signs may include difficulty in swallowing, bad breath, or loss of appetite. Tumors that appear around the peripheral nerves may be the culprit for the lameness, pain, or neurological symptoms experienced by your pet.
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Diagnosis Of Feline Sarcoma
Accurate diagnosis of feline sarcoma is very important because it determines the treatment procedures that have to be used. The vet will perform a series of blood tests to determine if the pet has any underlying disease. The signs and symptoms of sarcoma will also help thevet carry out diagnostic tests such as X-rays and scans. Ultrasounds are important to determine the size and density of the tumor. MRI scans are particularly helpful during diagnosis. After these preliminary testsare performed, the vet will conduct a biopsy of the tumor to find out the grade of the cancer present. The vet will also find out if the cancer has spread to other parts of the body, especially the lungs. Oncethe diagnosis is confirmed, the vet will adopt the appropriate treatment protocol to suit the type of sarcoma present.
Is It Safe To Vaccinate My Cat
Your veterinarian will discuss all aspects of the risks and benefits of vaccination with you. Vaccine manufacturers are actively investigating this concern, and most feline vaccines have adjuvant-free options. In general, the risk of your cat becoming infected with a serious disease is far greater than the very small risk of developing a sarcoma.
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Clinical Signs Of Sarcoma In Cats
The clinical signs of a feline soft tissue sarcoma can vary depending on its location and the tissue that is being affected. The following are some of the symptoms or signs you may notice if your cat develops this type of tumor:
- A lump or mass: These are typically slow growing
- Lameness: If the mass is located on one of your cats limbs or in an area that could restrict your felines movements, your cat may limp
- Pain: Soft tissue sarcomas are typically painless, but some such as ones that develop in the myelin sheath can cause pain. Thankfully, this is rare.
How Are Sarcomas Diagnosed
Your family veterinary surgeon will first of all want to examine your pet and the lump. They will likely feel the mass, determine whether it is mobile or fixed, and likely measure the diameter and record it on your petâs medical record for future reference and comparison.
Measuring the diameter of a mass when first found is very important to help keep track of how fast the lump is growing over time, and if in fact it is getting larger at allÂ©Fitzpatrick Referrals
The next step is likely to suggest using a needle and syringe to suck out a few cells and put them onto a glass slide for the pathologist to examine. It is likely a diagnosis can be made from this single test, but in some cases, a larger core biopsy might need to be taken, or even a thin wedge of tissue. These biopsies are often taken under sedation with local anaesthetic to numb the area, or sometimes under a very light anaesthetic.
Once your vet has made a diagnosis they will talk to you about âstagingâ the tumour, i.e. making sure there are no signs of spread within the body. This is normally done with a combination of x-rays, ultrasound, and in some cases a CT scan, which allows the radiologist to look inside body areas including the skull, lungs and abdomen for any early signs of cancer spread. A CT of the tumour itself also allows the family veterinary surgeon, or the specialist cancer surgeon, accurately plan surgery to make sure it is performed successfully.
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Diagnosis Of Soft Tissue Cancer In Cats
When you bring your cat in for its veterinary appointment, be sure to also bring the cats full medical history. The veterinarian will perform a complete physical examination of the cat. The presence of a lump does not confirm cancer, as many other types of tumors can develop in soft tissue areas. The vet will have to differentiate soft tissue sarcoma from other commonly occurring growths.
A fine needle aspiration may be used to collect small amounts of tumor tissue for testing. This test may provide a false negative as soft tissue tumors are very difficult to assess. The next step is to perform a biopsy, either excisional or incisional depending on the size and location of the tumor. A fine needle aspiration may also be needed for the lymph nodes if the cancer has metastasized.
Blood tests may be requested including a complete blood count and a blood serum biochemical test. Elevated white blood cell counts may confirm cancers presence in the body. Immunohistochemistry may be used to identify tissue components. An X-ray can be used to check for spreading tumors throughout the body. An ultrasound may prove more effective for monitoring the abdomen. A CT scan may be ordered to plan treatment if surgery is required.
Reducing Feline Cancer Risks
Its essential to incorporate practices that help reduce the risks of feline cancer for example, a good diet, exercise, low stress and avoidance of secondhand smoke, says Dr. Arteaga. Also, Be diligent about yearly vet appointments and biannual exams when a cat is older, as often, the disease will be caught earlier.
Always err on the side of safety and run past any new symptoms with your veterinarian. Early intervention is often key to effectively treating cancer in cats and improving their quality of life.
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Treatment Of Soft Tissue Cancer In Cats
If soft tissue sarcoma can be identified and treated while tumors are still few in number and localized in one part of the body, the outcome will be more successful. Because these tumors can be so irregular in shape, a combination of treatments carries the best prognosis.
Surgery can prove to be very effective at removing soft tissue tumors. As these tumors develop in difficult locations and vary in shape, a specialized veterinary surgeon is often needed to perform the surgery. Recurring tumors are far more challenging to treat, so it is imperative that the surgeon completes the removal on the first attempt. The cat will need general anesthesia for the procedure. A significant amount of surrounding tissue will also need to be removed, to ensure that small portions of the tumor do not remain. A second surgery may be required if any parts of the tumor remain. These surgeries are often not as successful.
This treatment is often administered along with surgical removal, as it is effective at destroying microscopic cancerous tissue. The area where tumors are present is subjected to radiation. This may be done before surgery to shrink large tumors, after surgery to remove small tumors, or in lieu of surgery for cats that are not healthy enough to undergo surgical removal of tumors. Cats are quite tolerant of radiation therapy, making it a common treatment for soft tissue sarcoma.