RESUMO
A 56-year-old male presented with inguinal lymphadenopathy and leucocytosis (WBC 98 x 10(9)/l). Bone marrow morphology showed myeloid hyperplasia, with eosinophilia. Cytogenetic analysis showed no evidence of the Philadelphia chromosome, and fluorescence in situ hybridisation studies for the BCR/ABL fusion were negative. All cells examined showed the t(8;13)(p11;q12) translocation. Six weeks after presentation, the disease progressed to an acute lymphoblastic leukaemia (ALL). The lymphoblasts were CD19/CD10 dual positive. Cytogenetic analysis again showed the t(8;13) translocation, with no additional abnormalities. There have been at least 14 reported cases of the t(8;13) myeloproliferative disorder to date, of which only 3 transformed to B-lineage ALL: our case is the 4th.