[Castleman's disease (giant lymph node hyperplasia): clinical, biological and developing polymorphism. Apropos of 4 cases].

Four cases of plasma cell type Castleman's disease (CD) are described. Two patients had localized forms (one mediastinal and the other mesenteric) and presented systemic manifestations associated with hypergammaglobulinemia and severe anemia. In both cases, the lesions were revealed by computerized tomography scans and cures were obtained by the complete surgical removal of the masses, which led to the rapid disappearance of the systemic manifestations. The other 2 patients had the multicentric form of CD and presented more extensive clinical and biological symptoms. One of these developed severe peripheral neuropathy and endocrine anomalies during the late phase of his disease, which led us to discuss the relationship between multicentric CD and the POEMS (polyneuropathy, organomegaly, endocrinopathy, M-protein, skin change) syndrome first described in Japan. Three of our patients presented with hypochromic microcytic anemia too severe to be explained by an inflammatory syndrome alone, and was likely due to several mechanisms. The etiology of CD remains unknown. The histological characteristics of angiofollicular lymph node hyperplasia are among the most important criteria for the diagnosis of localized and multicentric forms of CD, which can easily be made on a lymph node biopsy. However, it must be noted that this lesion can also be observed (but only rarely) in HIV (human immunodeficiency virus) - infected patients. The localized form is always considered to be benign, but, to date, there is no formal argument definitively supporting the malignancy of the multicentric one, in spite of its clinical similarity to a lymphoproliferative syndrome.