Isolated retroperitoneal Castleman's disease: A case report and literature review.

Unicentric Castleman's disease (CD) may rarely present as an isolated retroperitoneal tumor. Even experienced surgeons may misdiagnose CD because of its rarity. Surgeons should consider this disease when faced with an isolated retroperitoneal tumor. Unicentric CD is usually cured with surgical resection. In contrast, multicentric CD need numerous systemic therapies.