[A case of multicentric Castleman's disease with pulmonary involvement].

A 46-year-old man with polyclonal hypergammaglobulinemia was admitted to our hospital because of an abnormality on his chest radiograph findings. His chest CT showed a localized ground-glass opacity 21 mm in size in the right upper lobe, and some small nodules in all lung fields. He underwent video-assisted thoracoscopic surgery to establish a diagnosis. The histopathologic findings of the surgical specimens revealed the infiltration of lymphocytes and plasma cells. We diagnosed multicentric Castleman's disease. He did not wish to be treated because he had no symptoms. We took a wait-and-see approach and carefully followed him up. Multicentric Castleman's disease is extremely rare.