can cause fluid to collect around the lungs, leading to coughing and difficulty breathing. Hypercalcemia is most commonly associated with this type. Gastrointestinal lymphoma causes vomiting, diarrhea, and melena (digested blood in the stool). Low serum albumin levels and hypercalcemia can also occur. Lymphoma of the skin is an uncommon occurrence. The epitheliotropic form typically appears as itchy inflammation of the skin progressing to nodules and plaques. The non-epitheliotropic form can have a wide variety of appearances, from a single lump to large areas of bruised, ulcerated, hairless skin. The epitheliotropic form must be differentiated from similar appearing conditions such as pemphigus vulgaris, bullous pemphigoid, mycosis fungoides, and lupus erythematosus. Signs for lymphoma in 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 lead to glaucoma, uveitis, bleeding within the eye, retinal detachment, and blindness. Lymphoma in the bone marrow causes anemia, low platelet count, and low white blood cell count. Diagnosis Biopsy of affected lymph nodes or organs confirms the diagnosis, although a needle aspiration of an affected lymph node can increase suspicion of the disease. X-rays, ultrasound and bone marrow biopsy reveal other locations of the cancer. There are now a range of blood tests that can be utilised to aid in the diagnosis of lymphoma. Flow cytometry detects antibodies linked to tumour cell surface antigens in fluid samples or cell suspensions. Polymerase chain reaction (PCR) for antigen receptor rearrangements (PARR) identifies circulating tumour cells based on unique genetic sequences. The canine Lymphoma Blood Test (cLBT) measures multiple circulating biomarkers and utilises a complex algorithm to diagnose lymphoma. This test utilises the acute phase proteins (C-Reactive Protein and Haptoglobin). In combination with basic clinical symptoms, it gives in differential diagnosis the sensitivity 83.5% and specificity 77%. The TK canine cancer panel is an indicator of general neoplastic disease. The stage of the disease is important to treatment and prognosis. Certain blood tests have also been shown to be prognostic. The stage of the disease is important to treatment and prognosis. Stage I - only one lymph node or lymphoid tissue in one organ involved. Stage II - lymph nodes in only one area of the body involved. Stage III - generalized lymph node involvement. Stage IV - any of the above with liver or spleen involvement. Stage V - any of