A case of pulmonary nodular lymphoid hyperplasia with a resected cavity, followed by spontaneous regression of the remaining lesions.

A 50-year-old man was admitted to our hospital for examination of an abnormal shadow on chest radiography. Computed tomography revealed multiple small nodular shadows in bilateral lung fields, with cavitation in a right S3 lesion that was resected by video-assisted thoracoscopic surgery. Histopathological examination revealed marked proliferation of lymphoid tissue, including many plasma cells that were polyclonal in nature. This case was considered to be pulmonary nodular lymphoid hyperplasia (PNLH). Several residual nodules spontaneously disappeared during the 6 years of follow-up. This was a rare case of PNLH with a resected cavity, followed by spontaneous regression of the remaining lesions.