[Castleman's tumor with thoracic localization. Apropos of a case].

Castleman tumor usually presents as a mediastinal tumor which is never accurately diagnosed before surgery. Pathological findings and postoperative course establish the benign nature of this tumor. However, plasmocytic forms with prominent hematologic manifestations may be difficult to distinguish from a malignant lymphoma or thymoma. Differential diagnosis is all the more important that no complementary postoperative treatment is indicated in benign lymphoid tumors.