Lymphoma (lymposarcoma) in animals is a type of cancer defined by the proliferation of malignant lymphocytes in solid organs such as lymph nodes, bone marrow, liver and spleen. This disease can also occur in the eyes, skin, and digestive tract.
Video Lymphoma in animals
Lymphoma in dog
Lymphoma is one of the most common malignant tumors in dogs. The cause is genetic, but there are also environmental factors suspected of involvement, including in a study of increased risk with the use of 2,4-D herbicides. This risk is not confirmed in other studies.
Commonly affected breeds include Boxer, Scottish Terrier, Basset Hound, Airedale Terrier, Chow Chow, German Shepherd, Poodle, St. Bernard, Bulldog, Beagle, Rottweiler and Golden Retriever. Golden Retrievers are particularly vulnerable to developing lymphoma, with a 1: 8 lifetime risk.
Classification
Cancer is classified into low and high grade types. Classification is also based on location. The four types of sites are multicentric, mediastinal, gastrointestinal, and extranodal (involving the kidneys, central nervous system, skin, heart, or eyes). Multicentric lymphoma, the most common type (over 80 percent), is found in lymph nodes, with or without involvement in the liver, spleen, or bone marrow. Mediastinal lymphoma occurs in lymph nodes in thorax and possibly thymus. Gastrointestinal lymphoma occurs as a solitary tumor or a diffuse invasion of the stomach or intestine, with or without involvement in nearby lymph nodes, liver or spleen. Further classification is based on the involvement of B-lymphocytes or T-lymphocytes. About 70 percent are B cell lymphomas. Cutaneous lymphomas can be classified as epitheliotropic (very compatible with the epidermis) or non-epitheliotropic. The epitheliotropic form usually originates from T-cells and is also called mycosis fungoides. Non-epitheliotropic forms are usually derived from cell B.
Signs and symptoms
Common signs and symptoms include depression, fever, weight loss, loss of appetite, hair loss or fur and vomiting. Lymphoma is the most common cause of cancer of hypercalcemia (high blood calcium levels) in dogs. This can cause the above signs and symptoms plus increased drinking water, increased urination, and cardiac arrhythmias. Hypercalcaemia in this case is caused by secretion of proteins associated with parathyroid hormone.
Multicentric lymphoma emerges as a non-painful peripheral lymph node enlargement. This is seen in areas such as under the jaw, armpits, groin, and behind the knee. Enlarged liver and spleen cause enlargement of the stomach. Mediastinal lymphoma can cause fluid to collect around the lungs, causing coughing and difficulty breathing. Hypercalcaemia is most commonly associated with this type.
Gastrointestinal lymphoma causes vomiting, diarrhea, and melena (digesting blood in the stool). Low serum albumin levels and hypercalcemia may also occur.
Skin lymphoma is a rare occurrence. Epitheliotropic forms usually appear as an itchy inflammation of the skin that develops into nodules and plaques. Non-epitheliotropic forms can have a wide range of appearance, from single bumps to large areas of bruised, ulcerated, and hairless skin. The epitheliotropic forms should be distinguished from similarly emerging conditions such as pemphigus vulgaris, bullous pemphigoid, and lupus erythematosus.
The signs for lymphoma on other sites depend on the location. Central nervous system involvement can cause seizures or paralysis. Eye involvement, seen in 20 to 25 percent of cases, can cause glaucoma, uveitis, internal bleeding, retinal detachment, and blindness. Lymphoma in the bone marrow causes anemia, low platelet count, and low white blood cell count.
Diagnosis
Lymph node biopsy is exposed or the organ confirms the diagnosis, although needle aspiration of affected lymph nodes may increase the suspicion of the disease. X-rays, ultrasound and bone marrow biopsy reveal other sites of cancer. Now there are various blood tests that can be used to help diagnose lymphoma. Flow cytometry detects antigen-related tumor cell surface antigens in fluid samples or cell suspensions. Polymerase chain reaction (PCR) for antigen receptor rearrangement (PARR) identifies circulating tumor cells based on a unique genetic sequence. Blood Tests Canine Lymphoma (cLBT) measures some circulating biomarkers and uses complicated algorithms to diagnose lymphomas. This test uses acute phase proteins (C-Reactive Protein and Haptoglobin). In combination with basic clinical symptoms, the differential diagnosis of 83.5% and 77% specificity was compared. The TK canine cancer panel is a common indicator of neoplastic disease. Staging of the disease is important for treatment and prognosis. Certain blood tests also prognostic.
Staging of the disease is important for treatment and prognosis.
- Stage I - only one lymph node or lymphoid tissue in one organ is involved.
- Stage II - lymph nodes in only one area of ​​the body involved.
- Stage III - general lymph node involvement.
- Stage IV - all of the above with liver or spleen involvement.
- Stage V - all of the above with blood or bone marrow involvement.
Each stage is divided into substage a , without systemic symptoms; or substage b , those with systemic symptoms such as fever, loss of appetite, weight loss, and fatigue.
Treatment
Due to the high risk of recurrence and subsequent problems, close monitoring of dogs undergoing chemotherapy is important. The same applies to dogs who have entered forgiveness and discontinued treatment. Monitoring for illness and remission/recurrence is usually done by palpation of peripheral lymph nodes. This procedure detects rough changes in peripheral lymph nodes. Some blood tests used in the diagnosis of lymphoma also offer greater objectivity and provide early warning against animals that come out of forgiveness.
Complete cure is rare in lymphoma and treatment tends to be palliative, but long remission times are possible with chemotherapy. With an effective protocol, the first average remission time is 6 to 8 months. The second remission is shorter and more difficult to achieve. The average survival is 9 to 12 months. The most common treatments are the combination of cyclophosphamide, vincristine, prednisone, L-asparaginase, and doxorubicin. Other chemotherapy drugs such as chlorambucil, lomustine (CCNU), cytosine arabinoside, and mitoxantrone are sometimes used in the treatment of lymphoma alone or as a substitute for other drugs. In most cases, the right treatment protocol causes some side effects, but the number of white blood cells should be monitored.
Allogenic and autologous stem cell transplants (as is commonly done in humans) have recently proven to be a possible treatment option for dogs. Much of the basic research on transplant biology is produced in dogs. The current rate of healing using stem cell therapy in dogs approaches those reached in humans, 40-50%.
When cost is a factor, self-administered prednisone can improve symptoms dramatically, but does not significantly affect survival rates. The average survival time of dogs treated with prednisone and untreated dogs is one to two months. Using prednisone alone can cause cancer to be resistant to other chemotherapy agents, so it should only be used if more aggressive treatments are not an option.
Isotretinoin can be used to treat skin lymphoma.
Prognosis
An untreated dog has an average survival time of 60 days. Lymphomas with high histologic levels generally respond better to treatment but have shorter survival than those with low-grade lymphomas. Dogs with B-lymphocyte tumors have a longer survival rate than T-lymphocyte tumors. Mediastinal lymphomas have a worse prognosis than other types, especially those with hypercalcemia. Clinical and substage stages have some prognostic value, with a worse prognosis associated with Stage V disease, and with substage b (clinical disease at presentation).
Maps Lymphoma in animals
Lymphoma in cats
Lymphoma is the most common malignancy diagnosed in cats. Lymphoma in young cats occurs most often after infection with a cat leukemia virus (FeLV) or at a lower level of immunodeficiency virus (FIV). These cats tend to have lymph node, spinal, or mediastinal involvement. Cats with FeLV are 62 times more likely to develop lymphoma, and cats with FeLV and FIV are 77 times more likely. Younger cats tend to have T cell lymphoma and older cats tend to have B-cell lymphoma. Older cats tend to have gastrointestinal lymphoma without FeLV infection, although more sensitive tests of low-grade FeLV infection and deflated FeLV have found that many of these cats have been exposed previously. The same form of lymphoma found in dogs also occurs in cats, but gastrointestinal is the most common type. Kidney lymphoma is the most common kidney tumor in cats, and lymphoma is also the most common cardiac tumor.
Classification
Gastrointestinal lymphoma is classified as low, middle and high grade. Low class types include lymphocytic and small cell lymphomas. High class types include lymphoblastic, immunoblastic, and large cell lymphomas. Low-grade lymphoma is found only in the small intestine, whereas high levels can usually be found in the stomach.
Symptoms
Cats that develop lymphomas are much more likely to develop more severe symptoms than dogs. While dogs often seem healthy initially except for swollen lymph nodes, cats will often be physically sick. Symptoms are closely related to the location of the lymphoma. The most common place for gastrointestinal (lymphoma) lymphoma is, in decreasing frequency, small intestine, stomach, junction ileum, cecum, and colon. Cats with alimentary forms of lymphoma often present with weight loss, coarse hair, loss of appetite, vomiting and diarrhea, although vomiting and diarrhea are generally absent as a symptom. Tumors can also cause life-threatening gut blockages. Cats with mediastinal forms often have respiratory and fluid disorders in the thoracic cavity. If lymphomas develop in the kidneys, cats may experience increased water consumption and increased urination. Kidney lymphoma appears as a bilateral renal enlargement and failure. If the lymphoma is located in the nose, the cat may secrete fluid from the nose and swell the face. Cardiac lymphomas cause congestive heart failure, pericardial effusion, and cardiac arrhythmias. Ocular lymphoma in cats often appears as an anterior uveitis (inflammation of the inside of the eye). Cats that are also infected with FeLV often appear with pale mucous membranes due to anemia. Anemia is a common problem in all cats with lymphoma, but hypercalcaemia is rare.
Diagnosis is similar to dogs, except cats should be tested for FeLV and FIV. It is important to distinguish the alimentary form of lymphoma from inflammatory bowel disease because the signs are very similar in cats. A biopsy is needed to do this. One approach to distinguish inflammatory bowel disease from is to test infiltration lymphocytes for their monoclonal origin in lymphoma.
Treatment and prognosis
Chemotherapy is a mainstay of treatment for lymphoma in cats. Most of the drugs used in dogs are used in cats, but the most common protocols use cyclophosphamide, vincristine, and prednisone. Gastrointestinal lymphoma is also commonly treated with a combination of high doses of prednisolone and chlorambus with success. The number of white blood cells should be monitored. Remission and survival times are comparable to dogs. Low-grade lymphomas have a better prognosis. Multicentric lymphoma has a better response to treatment than gastrointestinal forms, but infection with FeLV worsens prognosis.
About 75% of cats treated with chemotherapy for lymphoma enter into remission. Unfortunately, after the initial remission, most cats have a recurrence, after which they have an average survival of 6 months. However, about a third of cats treated with chemotherapy will survive more than 2 years after diagnosis; a small number of these cats can be cured of their diseases. Untreated, most cats with lymphoma die within 4-6 weeks. Most cats tolerate their chemotherapy well, and less than 5% have severe side effects. Cats do not lose their feathers from chemotherapy, although the loss of a mustache may occur. Other side effects include low white blood cell count, vomiting, loss of appetite, diarrhea, or fatigue. These can usually be well controlled, and most cats have a good quality of life during the treatment. If the cat recurs after receiving remission, the cat can be treated with different chemotherapy drugs to try the second remission. The possibility of a second remission is much lower than the likelihood of obtaining the first, and the second remission is often shorter than the first.
Lymphoma in civet
Lymphoma often occurs in ferrets and is the most common cancer in young ferrets. There is some evidence that retroviruses may play a role in the development of lymphoma as in cats. The most commonly affected tissues are lymph nodes, spleen, liver, intestine, mediastinum, bone marrow, lung, and kidney.
In young ferrets, the disease develops rapidly. The most common symptoms are breathing difficulty caused by thymic enlargement. Other symptoms include loss of appetite, weight loss, weakness, depression, and cough. It can also be disguised as a chronic illness such as upper respiratory tract infection or gastrointestinal disease. In older civets, lymphomas are usually chronic and can not show symptoms for years. Symptoms that look the same as in young ferrets, plus splenomegaly, abdominal mass, and enlargement of peripheral lymph nodes.
Diagnosis is done through biopsy and x-rays. There may also be an increase in the number of lymphocytes. Treatments include surgery for a solitary tumor, splenectomy (when the spleen is very large), and chemotherapy. The most common protocols use prednisone, vincristine, and cyclophosphamide. Doxorubicin is used in some cases. Chemotherapy in relatively healthy females is well tolerated, but side effects may include loss of appetite, depression, weakness, vomiting, and loss of a mustache. The number of white blood cells should be monitored. Prednisone used alone can work very well for weeks to months, but can cause resistance to other chemotherapy agents. Alternative treatments include vitamin C and Pau d'Arco (bark extract).
The prognosis of civet lymphoma depends on the health and location of the cancer. Lymphomas in the mediastinum, spleen, skin, and peripheral lymph nodes have the best prognosis, while lymphoma in the intestines, liver, abdominal lymph nodes, and bone marrow have the worst.
See also
- Lymphadenopathy
References
Source of the article : Wikipedia
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