Inclusion Criteria:

   - Patients must have histologically confirmed recurrent de novo or transformed diffuse
   large B cell lymphoma (DLBCL) or one of its variants according to WHO classification
   (centroblastic, immunoblastic, T-cell/histiocyte rich and anaplastic variants)

   - Eastern Cooperative Oncology Group (ECOG) performance status must be 0 or 1

   - Patients must have measurable disease as defined in section 6 assessed within 4 weeks
   of registration

   - Patients must have failed one or more prior Non-Hodgkin lymphoma (NHL) chemotherapy or
   antibody therapy with curative intent; autologous stem cell transplant is permitted

   - Leukocytes >= 2,000/mm^3

   - Absolute neutrophil count >= 1,000/mm^3

   - Platelets >= 75,000/ mm^3

   - Total bilirubin =< 2.0 X normal institutional limits

   - Aspartate Aminotransferase (AST) =< 2.5 X institutional upper limit of normal

   - Alanine Aminotransferase (ALT) =< 2.5 X institutional upper limit of normal

   - Creatinine within normal institutional limits; creatinine clearance calculated or
   measured at >= 60 ml/min/1.73m^2 if creatinine level is above institutional limits

   - The prothrombin time (PT)/international normalized ratio (INR) within Institutional
   limits of normal

   - Patients with underlying hypertension as defined by blood pressures averaging greater
   than 140/90 on two separate clinic visits are eligible if hypertension has been
   controlled by standard nonpharmacologic and pharmacologic therapy

   - Patients must be physically able to orally ingest tablets

Exclusion Criteria:

   - Central nervous system (CNS) involvement

   - Previously treated with Sorafenib (BAY 43-9006) or other small molecule targeted
   inhibitors of mitogen-activated protein kinase (MAPK) signaling intermediates or
   angiogenesis (e.g. bevacizumab)

   - Progressed within 60 days of last therapy

   - Prior allogeneic stem cell transplant

   - Candidates for potentially curative therapy, such as hematopoietic stem cell
   transplantation (HSCT)

   - Currently receiving any other investigational agents

   - History of allergic reactions attributed to compounds of similar chemical or biologic
   composition to sorafenib

   - Uncontrolled intercurrent illness including, but not limited to: ongoing or active
   infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
   arrhythmia or psychiatric illness/social situations that would limit compliance with
   study requirements

   - Active HIV infection, because of possible pharmacokinetic interactions of
   anti-retroviral therapy with BAY43-9006

   - Evidence of bleeding diathesis

   - Currently taking the cytochrome P450 enzyme-inducing anti-epileptic drugs (phenytoin,
   carbamazepine and phenobarbital), rifampin or St. John's Wort

   - Pregnant or Breast-feeding; all females of childbearing potential must have a blood
   test or urine study within 2 weeks prior to registration to rule out pregnancy. Women
   of childbearing potential and sexually active males must be strongly advised to use an
   accepted and effective method of contraception