A multicentric form of Castleman's disease is described, this being a rare affection for which CT image characteristics have not, to our knowledge, been reported. Two cases of localized and one case of multicentric Castleman's disease are reported, and differential characters of these two forms with common histology: angio-follicular lymphoid hyperplasia, outlined. The localized form is found mainly in the mediastinum in young patients and follows a favorable course with recovery after exeresis. The diffuse form develops in later life and presents with severe systemic signs and a marked biological inflammatory syndrome Glands and viscera are affected and its course is grave, with mostly fatal relapses. Angiography suggests diagnosis when images show hypervascular lesions in lymph glands. CT scan imaging with contrast is very suggestive when glandular lesions are present that take up contrast strongly. This appearance should always raise the possibility of Castleman's disease.