I have heard that the use of prednisone can make the diagnosis of lymphoma on a biopsy more difficult. Is this true? Would the length of use make a difference? Thank you-

The use of prednisone does indeed make the diagnosis of lymphoma more difficult. Prednisone will alter the way lymphoma cells look under the microscope. In general, we try to avoid the use of prednisone, until a biopsy is done so that we can accurately diagnosis a lymphoma before its appearance is altered. Quite often, however, the use of prednisone can NOT be avoided. As just one example, if a patient comes in with a huge mass in his brain, physicians often prescribe prednisone (or dexamethasone) to shrink the mass in order to relieve the pressure in the brain. This is often done before a biopsy is done just because the pressure in the brain is an emergency.