Ground-glass lung lesions on CT are treatable with limited excision

Feb 9, 2003

Japanese researchers are relying on high-resolution CT to spot increasingly smaller lung lesions, according to a presentation at the 2002 Society of Thoracic Surgeons meeting in San Diego earlier this month. On the CT scan, these ground-glass-opacity lesions have a far different prognosis than do similar-sized solid lesions.

"These ground-glass-opacity lesions are true early cancers," said Dr. Hisao Asamura, a researcher at the National Cancer Center Hospital in Tokyo. His CT studies indicate that the ground-glass-opacity lesions progress to becoming partially solid and then solid.

The ground-glass lesions -- which are clear enough for visualization of blood vessels that are underneath the lesion -- appear to have few invasive characteristics, he explained. On the other hand, solid tumors, even those that are less than a centimeter in size, have invasive characteristics and require lobectomy, he said. But in some cases the treatment of smaller, ground-glass lesions can be curative without major lung resection, he said.

In his study, Asamura reviewed findings of lung tumors less than a centimeter in diameter that were found in CT screening programs, or were found incidentally through x-ray and CT procedures for other indications.

In a review of data collected over the past 10 years, Asamura and colleagues noted that 1,769 lung cancers were resected. Of that group, 48 were less than a centimeter in size and fell into three categories:

Simple ground-glass-opacity type. There were 19 of these tumors, which did not obscure the bronchovascular structure. The histology showed these tumors were bronchioloalveolar carcinoma or adenocarcinoma with predominantly bronchioloalveolar spread.

Complex ground-glass opacity. Seen on 9 CT exams. These lesions contained a solid area as well as a clear area. The histology of these tumors was similar to the simple ground-glass-opacity lesions.

Solid lesions. The researchers identified 20 of these lesions. These tumors were also predominantly adenocarcinomas, but two were squamous cancer, one was small-cell lung cancer and was one characinoid. Lymph-node involvement was observed only in three solid lesions.

Limited resection was performed in 15 of the 29 tumors showing ground-glass expression, and in four of the solid tumors. Tumor recurrence occurred in two solid lesions; one each in bone and locoregional lymph nodes. There were no cancer-related deaths.

For all three lesion types, age and gender distributions were similar, with an average of 61 years and almost even male-to-female distribution. Twenty-six tumors were screen-detected; the others were found incidentally.

By Edward Susman
AuntMinnie.com contributing writer
February 10, 2003
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