Accessory spleen: Differential diagnosis for lymphoma in autoimmune lymphoproliferative syndrome

Mutations of Fas or, less frequently, Fas ligand genes result in a rare inherited lymphoid disorder called autoimmune lymphoproliferative syndrome (ALPS) in which lymphoma frequency is increased. We report on a patient with ALPS who had been splenectomized for giant splenomegaly and progressively developed a voluminous abdominal tumor. The histology of the removed tumor revealed that it was an accessory spleen exhibiting typical features of ALPS involvement, as shown by the presence of a large excess of CD3 + CD4 − CD8 − T cells and plasma cells without a detectable monoclonal population. This observation highlights the lymphoma's differential diagnosis in this context. Pediatr Blood Cancer 2010;54:1020–1022 © 2010 Wiley‐Liss, Inc.