Polymerase chain reaction on cerebrospinal fluid cells in suspected leptomeningesl involvement in childhood acute lymphoblastic leukemia: comparison to cytomorphological analysis - Scrideli, Carlos Alberto; Queiroz, Rosane Gomes de Paula; Takayanagui, Osvaldo Massaiti; Bernardes, José E.; Tone, Luiz Gonzaga (Diagnostic Molecular Pathology, 2003)