ABSTRACT
Castleman's disease is a benign disorder characterized by hypervascular lymphoid hyperplasia. The etiology of the disease is still unknown. Although it may occur at the various sites such as peritoneum, retroperitoneum, pelvic lymph node, muscle and lung, it occurs most commonly at the mediastinum. Even though specific pathophysiologic relations are still not clearly determined between two different histologic types -hyaline vascular type and plasma cell type-, there were several previous reports dealing with the plasma cell type transformed or progressed into different types of malignancies such as malignant lymphoma, Kaposi's sarcoma and Hodgkin's disease. We experienced a case of plasma cell type Castleman's disease that transformed into a malignant lymphoma and report this case with review of literatures.