WHAT IS LYMPHOMA IN DOGS?WHAT ARE THE CLINICAL SIGN AND WHAT SHOULD THE DIAGNOSTIC WORK UP INCLUDE?

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Todays Tips-Lymphoma in dogs &its Clinical sign & the diagnostic work-up include:
Lymphoma and lymphosarcoma (LSA) are interchangeable terms
Lymphoma in dogs is similar to non-Hodgkin's lymphoma in a man
Lymphoma represents 7% of all cancers in dogs affecting 24/100,000 dogs at risk each year
Most affected dogs are between 5-9 years of age, but the disease can occur in dogs of any age
Generalized lymphadenopathy (lymph node enlargement) in an otherwise healthy dog is the most common presentation
Hypercalcemia occurs in 20% of dogs with lymphoma
Administration of glucocorticoids (steroids) prior to confirming a diagnosis can make obtaining the diagnosis more challenging
The Clinical Sign:
Generalized lymph node enlargement in an otherwise healthy dog is the most common presentation of LSA. This lymphadenopathy is non-painful and generally asymptomatic. This clinical presentation is referred to as stage IIIa LSA. Clinical signs will vary depending on the stage of disease, volume of tumor and anatomic location of the lymphoma. Clinical signs are typically non-specific and may include lethargy, weight loss and loss of appetite. If the patient has associated hypercalcemia, clinical signs will include polydipsia and polyuria (frequent drinking and urination). Other symptoms reflect the anatomic location of the lymphoma. Lymphoma of the gastrointestinal system generally results in vomiting and/or diarrhea whereas cranial mediastinal lymphoma results in dyspnea (difficulty breathing).
The diagnostic work-up include:
A thorough physical examination is the most important part of the work-up. This dictates what diagnostic tests will be required to confirm the diagnosis and accurately determine the patient's health status. The diagnostic work-up should always include a complete blood count (CBC), platelet count, biochemical profile, urinalysis and fine needle aspirate or excisional biopsy of the lymph node. These tests allow us to confirm the diagnosis, determine if the patient is hypercalcemic, assess kidney function, and determine if the patient has normal neutrophil and platelet counts so that we can safely initiate chemotherapy.
A lymph node is excised for histopathologic analysis when the diagnosis cannot be confirmed by cytology. Lymph node biopsy has the added advantage of histologically classifying the LSA, which provides some additional prognostic information.
Alternatively, a DNA (gene) analysis test called PCR performed from a lymph node aspirate can be helpful to confirm a diagnosis in most cases.
When collecting a fine needle aspirate of the lymph node for cytologic evaluation, it is optimal to stay as far away from submandibular lymph nodes as possible. The increased reactivity of submandibular lymph nodes can sometimes mask neoplastic infiltrates. These lymph nodes should be only be used if other lymph nodes are not sufficiently enlarged or less accessible.
Additional diagnostic tests are required when complete staging of the lymphoma is desirable or when the patient is symptomatic. These tests may inclued chest and abdominal radiographs, abdominal ultrasound and ultrasound guided aspirates of the liver and spleen for cytologic evaluation, and bone marrow aspirate.