Transformation of follicular lymphoma

Abstract

Histological transformation of follicular lymphoma (FL) to a more aggressive non-Hodgkin's lymphomas is a pivotal event in the natural history of FL and is associated with poor outcome. While commonly observed in clinical practice and despite multiple studies designed to address its pathogenesis, the biology of this process represents an enigma. In this chapter we present a state of the art review summarizing the definition of histologic transformation, its incidence, pathogenesis, clinical manifestations, treatment and outcome. Furthermore, we specifically emphasize gaps in our knowledge that should be addressed in future studies.

Copyright © 2011 Elsevier Ltd. All rights reserved.

Figures

Figure 1

Transformation of FL to aggressive lymphoma most commonly takes one of three forms, A) diffuse large B cell lymphoma, B) unclassifiable B cell lymphoma with features intermediate between DLBCL and Burkitt lymphoma and finally, C) a blastoid lymphoma with fine chromatin (rare Tdt+ blastoid lymphomas may be seen as a transformation event following FL that show double-hit cytogenetics with translocations of BCL2 and MYC)

Figure 2

Biological factors associated with histologic transformation of FL to DLBCL. These include both genetic alterations harbored by the malignant B cells and factors that influence the tumoral microenvironment. UPD = uniparental dizomy, FDC = follicular dendritic cells, PD = programmed death and MVD = microvessel density.

Figure 3

Suggested therapeutic approach to patients with transformed FL.