Fig. 2.

Operative findings and histological findings. a The tumor existed between middle and lower lobe of the right lung. Because no tumor invasion into the pulmonary artery and/or lung parenchyma were found, only the tumor enucleation was carried out. b There were clearly hyalinizing concentric fibrotic nests around the lymph follicle and vessel hyperplasia on the hyalinizing wall. There were almost no plasma cells outside the follicle. Histological diagnosis was HV type CD