Castleman's disease (CD) is a rare disorder characterized by non-cancerous tumor growth that may develop in the lymph node tissue at a single site or throughout the body (Castleman et al. in Cancer 9:822-830, 1956). It involves hyperproliferation of specific B cells that produce the cytokine IL-6. This disorder is often undiagnosed or misdiagnosed. For this reason, only very few patients have been reported, and little information is available in the literature. In hopes of providing a better understanding of this rare disease, this report examines 52 patients with Unicentric Castleman's disease (UCD) and Multicentric Castleman's disease (MCD) treated from 1999-2008 at a single institution. Fifty-two patients with CD, along with their histological diagnoses, were collected. Patients were divided into two groups--the more common UCD and the less common MCD. Relevant clinical, pathological, and laboratory data were examined in order to evaluate treatment responses, with symptom onsets and survival period serving as the endpoints of the assessment. Each of the 48 patients with UCD exhibited benign symptoms and underwent a curative surgical resection with excellent prognosis. All of the four patients with MCD received surgical resection. Three of the four patients relapsed and received radiotherapy and/or chemotherapy. Only one of the three post-treatment patients survived. UCD is manifested in the form of benign, painless, slow lymph node enlargement that is generally asymptomatic. Complete surgical removal is recommended as a course of curative treatment. The multicentric form of CD exhibits a progressive clinical course with potential for malignancy. There is currently no standard therapy for MCD.