Minute Lung Carcinoma Associated with Focal Honeycombed Lesion.

We report a case of minute lung carcinoma that developed in a focal honeycombed lesion in the right lung. A 70-year-old man presented hemosputum, and a cytological examination result was at class IV. A right lower lobectomy of the lung was performed. Microscopically, the thickened alveolar wall revealed tumor cells indicating a minute carcinoma, and showed squamous hyperplasia, metaplasia, and dysplasia, with the carcinoma in the distal airway epithelium. This peripheral lung carcinoma in a focal honeycombed lesion demonstrated the various stages of multistep carcinogenesis, which is recognized in hilar type squamous cell carcinoma. To date, the association between a honeycombed lesion and lung cancer has been poorly described. Here we have presented clear evidence of the association of this carcinoma with the honeycombed lesion.