A case of lung adenocarcinoma presenting a solitary, predominantly solid pulmonary nodule that showed slow growth over 7 years]

A small, solitary, predominantly solid pulmonary nodule (7 x 6 mm) was found in a 63-year-old woman during a CT screening for lung cancer. After 7 years, another chest CT examination revealed that the lesion had grown to a size of 15 x 10 mm. The patient then underwent surgery to remove the nodule, because primary lung cancer was strongly suspected. The resected specimen proved to be a poorly differentiated adenocarcinoma of type D according to the criteria of Noguchi et al. The tumor doubling time (TDT) in this case was estimated to be 661 days, which was longer than in other reported cases of Noguchi type D adenocarcinoma. High-resolution CT (HRCT) of the nodule revealed a predominantly solid lesion with a polygonal shape. No further changes were observed in a one-year follow-up CT, suggesting a benign tumor. We therefore suggest that the follow-up of small, solitary pulmonary nodules is of diagnostic value.