LEPTOMENINGEAL INVOLVEMENT IN CHRONIC LYMPHOCYTIC-LEUKEMIA IDENTIFIEDBY POLYMERASE CHAIN-REACTION IN STORED SLIDES - A CASE-REPORT

The use of polymerase chain reaction (PCR) for routine detection of cl onal immunoglobulin heavy-chain (IgH) gene rearrangements represents a n attractive alternative to Southern hybridization analysis not only b ecause PCR protocols are quicker and simpler, but also because of the ability to analyze very small population of cells in search of minimal residual disease. This can be especially important for the detection of clonal malignant cells in locations other than bone marrow or perip heral blood. We describe a case in which central nervous system involv ement, a very rare complication of chronic lymphocytic leukemia, was c onfirmed by PCR analysis for IgH genes rearrangement of the lymphocyte s found in cerebrospinal fluid. The cerebrospinal fluid and the periph eral blood lymphocytes (obtained from archival cytospins stored at the time of diagnosis, 5 years before) presented an identical IgH gene re arrangement, as shown by sequence analysis, Thus, the use of PCR for I gH genes rearrangement can be very useful in the detection of monoclon ality in samples with a small number of cells and in the confirmation of the common origin of B cells in different specimens of the same pat ient.