Leukemia and lymphoma cells can be found in cerebrospinal, pleural, peritoneal, and pericardial fluids at the time of diagnosis as well as anytime during the course of the disease. They can be found in any of these fluids, even when no abnormal cells are present in the peripheral blood.
Just as there are many morphological variations of leukemia and lymphoma cells in the peripheral blood and bone marrow, there are as many variations of leukemia/lymphoma cells in cytospins from fluids.
Once the diagnosis is made from the initial tissue samples, there may be frequent spinal taps performed to monitor disease status and to instill intrathecal chemotherapy to prevent the development of central nervous system involvement by the leukemia or lymphoma.
Cytospins are made for each sample and must be meticulously scrutinized. If any smears display abnormalities indicative of a disease state, or if there are any suspicious cells, they should be sent for hematology or pathology review in accordance with your laboratory's review policy.