Early transformation event from follicular lymphoma: our experience of four cases.

Follicular lymphoma (FL) is a mature B-cell lymphoma that can transform into a more aggressive disease such as diffuse large B-cell lymphoma, Burkitt lymphoma, or precursor B-lymphoblastic leukaemia/lymphoma. The process of transformation of FL occurs by the acquisition of additional genetic alterations, e.g. c-MYC rearrangement, TP53, and cyclin D1 inactivation. Herein, we describe four such cases of FL that transformed into more aggressive B-cell non-Hodgkin lymphomas within six months of their initial diagnosis. Subsequent testing of c-myc, P53 and cyclin D1 by immunohistochemistry and fluorescence in situ hybridization was done to further analyse their role in the process of transformation.