[A case of pseudo-tumoral lymphoid hyperplasia or Castleman's disease].

The relatively rare pseudotumoral lymphoid hyperplasia (benigh lymphoid or reactive lymphoreticular hyperplasia; pseudolymphoma; Castleman's disease) arises from the lymph nodes, usually in the mediastinum. The disease assumes tow histologically and clinically different forms: the first, angiofollicular, is often symptomless, while the second, lymphoplasmocytic, is sometimes associated with a marked chronic inflammatory syndrome. The etiology is unknown, but is probably a reaction of the lymphoplasmocytic system to an antigen, possibly of viral origin. Diagnosis is based on histology. Surgical treatment is curative. A rare form of this unusual disease is reported with reference to the morphological differential diagnosis; the similarities with immunoblastic lymphadenopathy are emphasized.