A Study to Provide RoActemra/Actemra (Tocilzumab) to Patients With Multicentric Castleman's Disease Who Demonstrated Benefit From Previous RoActemra/Actemra Treatment

Inclusion Criteria: * Adult patients, \>/= 18 years of age * Evidence of improvement of one or more clinical benefit criteria with acceptable tolerability to RoActemra/Actemra in Protocol MRA001US, maintained clinical benefit in MRA004US, and completion of MRA004US * Life expectancy \> 12 weeks * Zubrod performance status \</= 3 Exclusion Criteria: * Serious toxicity including anaphylactic reactions to tocilizumab during the MRA004US trial * Any treatment for Multicentric Castleman's Disease except for corticosteroids within 2 weeks prior to Day 1 * Active infection requiring iv antibiotics for \> 1 month and not resolving at least 1 week prior to Day 1; iv antibiotics prophylaxis for infections of implanted venous access portals is allowed * Active viral infection within 28 days prior to Day 1 * Treatment with any investigational agent other than RoActemra/Actemra within 30 days prior to baseline