Clonally unrelated primary large B-cell lymphomas separated by over a decade involving the central nervous system and testicle: Possible predisposition to lymphomas of immune-privileged sites?

Primary large B-cell lymphomas of immune-privileged sites (IP-LBCLs) comprise LBCLs arising within "immune sanctuaries," including the central nervous system (CNS), vitreoretina, and testes. Although patients present with localized disease, the prognosis remains poor with high relapse rates, either at the originating site or within another immune-privileged site. Generally, in the presence of an antecedent IP-LBCL, subsequent LBCLs are expected to be clonally related. However, we present a primary CNS LBCL and later primary testicular LBCL in a middle-aged man, diagnosed over a decade apart, which proved to be clonally unrelated by targeted ultra-deep next-generation sequencing of the IgH locus.