Stepwise progression from ground-glass opacity towards invasive adenocarcinoma: long-term follow-up of radiological findings.

The natural history of lung adenocarcinoma with ground-glass opacity (GGO) remains undetermined. We describe a lung adenocarcinoma in which GGO transformed through a scar-like lesion over the long term into a solid nodule of poorly differentiated adenocarcinoma. Whether poorly differentiated lung adenocarcinoma can evolve from GGO-type adenocarcinoma is an important issue that requires clarification.