A Case of Polyclonal Hyperglobulinemia with Multiple Pulmonary Cysts and Nodules: Concerning the Mechanism Underlying Cyst Formation

We herein report a case of polyclonal hyperglobulinemia with multiple pulmonary cysts and nodules. The histopathological findings allowed us to speculate about the mechanism underlying cyst formation in these pathological conditions, which has not yet been thoroughly elucidated. The patient was a 49-year-old woman who presented with multiple pulmonary multilocular cysts and nodules. A lung biopsy revealed features of nodular lymphoid hyperplasia. Notably, lung structure fragmentation was evident, suggesting that structural destruction may have accompanied the disease during its course. The cysts were considered to have formed due to destruction of the lung structures.