Treatment for primary CNS lymphoma includes chemotherapy and often radiation therapy. Steroid therapy (. dexamethasone) is often given before chemotherapy, as this helps reduce the swelling around the tumour, and may even shrink the tumour, reducing the raised intracranial pressure. Chemotherapy is given into a vein, and often also into the fluid surrounding the brain (intrathecally). Methotrexate is the drug most commonly given this way, and is also given in high doses intravenously- either on its own or in combination with other chemotherapy drugs and/or steroids. Radiotherapy uses high-energy rays to destroy the cancerous cells and can be an effective treatment for primary CNS lymphoma in younger people. It is used in combination with chemotherapy and steroid treatment. Surgery is only used to provide diagnostic tissue, and is never curative alone. Anticonvulsants may be given if seizures occur as a result of a tumour.
Dog; blood samples analyzed in a flow cytometer; red blood cells have been lysed. A, control dog; leukocytes form clouds of cells with low side scatter and low forward scatter (1 = lymphocytes), intermediate side scatter and higher forward scatter (2 = monocytes), and high side scatter (3 = granulocytes). Within gate 1, mutually exclusive staining is recognized for CD4 and CD8 (expressed on T lymphocytes; CD4 + cells outnumber CD8 + cells in health); CD21 + B lymphocytes comprise 20 to 30% of lymphocytes; and most lymphocytes express MHC II. B, dog, chronic lymphocytic leukemia (35,600 leukocytes/µl). The lymphocyte cloud (1) contains a greater number of cells relative to monocytes (2) and granulocytes (3) and has a tail of cells with higher forward scatter. The cells in the lymphocyte gate are uniformly CD8 + and most express MHC II. There is lymphocytopenia of CD4 + and CD21 + cells. C, dog, acute leukemia, undifferentiated (25,200 leukocytes/µl). There is a uniform population of cells with relatively high side scatter and intermediate forward scatter (4) and with absence of typical lymphocyte and granulocyte populations. The cells do not express antigens of differentiated lymphocytes, but approximately 70% express CD34, a marker of early hematopoietic cells.