- Histologically confirmed mantle cell lymphoma (MCL); the diagnosis must be confirmed by NCCTG pre-registration pathology review by Dr. Paul Kurtin or his designate; it is recommended that the biopsy be an excisional biopsy, but adequate core-needle biopsies will be accepted as long as they are considered adequate for registration by Dr. Kurtin or his designate; the tumor must be cyclin D-1 positive by immunohistochemistry or have evidence of a t(11;14) translocation by fluorescence based in situ hybridization (FISH) or cytogenetics