An Extra Ordinary Respone of Castleman’s Disease to Rituximab.

Castleman’s disease is a very rare non-neoplastic lymphoproliferative disorder of unknown cause that is diagnosed on a pathological basis. It is often associated with autoimmune diseases, and diagnosed in the context of human immunodeficiency virus (HIV) positive patients. No standard treatment has been developed for this rare disease.

CASE REPORT: This 54-year-old male presented with nausea and vomiting. He has a past medical history of hypertension and chronic glomerulonephritis. His laboratory results showed acute renal failure. Hemodialysis was started prior to further work up. A chest x-ray showed bilateral hilar lymphadenopathy that was later confirmed by computerized tomography (CT) of the chest. A mediastinoscopy and mediastinotomy were performed. Mediastinal lymph node biopsy showed findings consistent with Castleman’s disease including atrophic follicles with hyalinized vessels. Remission was obtained for one year by prednisone and cyclophosphamide, but the patient relapsed with multiple lymphadenopathy. Biopsy confirmed the recurrence of Castleman’s disease. Rituximab was added to cyclophosphamide as a treatment regimen and for more than two years the patient has done extremely well. His kidney function returned to his baseline, hemodialysis was stopped, and the patient has long-term remission on CT scan and postron emission tomography (PET).

DISCUSSION: Castleman’s disease is lymphadenopathy of unknown cause. About 400 patients have been reported to date. It is diagnosed microscopically by lymphadenopathy with angiofollicular hyperplasia and plasma cell infiltration. It has a rapid progressive and often fatal course. Traditional treatment is chemotherapy. A new trend in the treatment of Castleman’s disease is Rituximab which is a monoclonal antibody that showed success in HIV positive patients with Castleman’s disease. We believe that this is the first reported case of long-term remission of Castleman’s disease in an HIV-negative patient treated with Rituximab and chemotherapy.