Inclusion Criteria:

- Patients must have histological documented or cytological confirmed mantle cell
lymphoma; cyclin D1 must be present as evidenced by either fluorescence in situ
hybridization (FISH) or immunohistochemical staining

- Patients must have undergone autologous hematopoietic stem cell transplantation
(AHCT) and achieved engraftment by D60-180 as evidenced by absolute neutrophil count
(ANC) > 1000/mcL and platelets (Plt) > 75,000/mcL

- Patients must be in complete remission at D60-180 after AHCT as evidenced by computed
tomography (CT) scan of the neck/chest/abdomen (abd)/pelvis or CT/positron emission
tomography (PET) scans

- Voluntary written informed consent before performance of an study-related procedure
not part of normal medical care, with the understanding that consent may be withdrawn
by the subject at any time without prejudice to future medical care

- Female subject is either post-menopausal or surgically sterilized or willing to use
an acceptable method of birth control (i.e., a hormonal contraceptive, intra-uterine
device, diaphragm with spermicide, condom with spermicide, or abstinence) for the
duration of the study

- Male subject agrees to use an acceptable method for contraception for the duration of
the study

- Life expectancy of greater than 3 months

- Karnofsky > 60%

- ANC > 1000/mcL

- Plts > 75,000/mcL

- Total bilirubin within normal institutional limits, patients with elevation of
unconjugated bilirubin alone, as in Gilbert's disease, are eligible

- Aspartate aminotransferase (AST)/alanine aminotransferase (ALT) < 2.5 X institutional
upper limit of normal

- Creatinine up to and including 2 mg/dL

Exclusion Criteria:

- Patient has >= grade 2 peripheral neuropathy within 14 days before enrollment and at
D60-180 after AHCT; patients who had >= grade 2 peripheral neuropathy within 14 days
before enrollment but resolves to grade 1 or lower peripheral neuropathy at D60-D180
after AHCT can be enrolled at this time

- Patient has > 1.5 x upper limit of normal (ULN) total bilirubin unless history of
Gilbert's syndrome

- Myocardial infarction within 6 months prior to enrollment or has New York Heart
Association (NYHA) Class III or IV heart failure, uncontrolled angina, severe
uncontrolled ventricular arrhythmias, or electrocardiographic evidence of acute
ischemia or active conduction system abnormalities; prior to study entry, any
electrocardiographic (ECG) abnormality at screening has to be documented by the
investigator as not medically relevant

- Patient has hypersensitivity to bortezomib, boron or mannitol

- Female subject is pregnant or breast-feeding; confirmation that the subject is not
pregnant must be established by a negative serum beta-human chorionic gonadotropin
(beta-hCG) pregnancy test result obtained during screening; pregnancy testing is not
required for post-menopausal or surgically sterilized women

- Patient has received other investigational drugs with 14 days before treatment of
treatment with bortezomib + rituximab

- Serious medical or psychiatric illness likely to interfere with participation in this
clinical study

- Diagnosed or treated for another malignancy within 3 years of enrollment, with the
exception of complete resection of basal cell carcinoma or squamous cell carcinoma of
the skin, an in situ malignancy, or low-risk prostate cancer after curative therapy

- Patients with other active malignancies (no evidence of other cancer or life
expectancy greater than 5 years) are ineligible for this study

- Human immunodeficiency virus (HIV) positive patients or Hepatitis B or C positive
patients due to risk of reactivation from marrow-suppressive therapy and Rituximab

- Patients with active central nervous system (CNS) disease or history of brain
metastases (mets) are excluded from study

- Prior exposure to either bortezomib or rituximab is not an exclusion criteria