Bilateral localized Castleman disease of the retroperitoneum.

A case report of a 23-year-old patient with abdominal pain was found to have a bilateral, retroperitoneal localized form of Castleman disease. To the best of our knowledge, it is the first report of a bilateral form described in the literature. Surgical excision resulted in the disappearance of symptoms and both masses were found to be of the hyaline type. Follow-up computerized tomography revealed no pathological sequelae.