Castleman's disease (CD) is a rare atypical lymphoproliferative disorder with frequent, yet less well known renal involvement. We describe the case of a 58-year-old woman with localised abdominal plasma-cell type CD complicated by nephrotic syndrome due to renal amyloidosis. 18Fluorodeoxyglucose (FDG) positron emission tomography (PET) confirmed the unicentric nature. Resection of the mass resulted in regression of the signs of inflammation, a negative FDG-PET and complete remission of the nephrotic syndrome. A review of the literature of renal involvement (incidence, clinical and pathological manifestations, treatment and prognosis) in CD is provided.