Interestingly, both cases showed expression of cyclin E. Notably, all 3 blastoid MCLs showed a monoallelic deletion of RB1 associated with a lack of expression of RB1 protein and monoallelic loss of p16.
Compared with mantle cell lymphoma, there was more frequent p15 (P=.025) hypermethylation but comparable Rb1 (P=.07) and p16 (P=.07) hypermethylation in follicular lymphoma.