Introduction: When pure ground-glass opacity (GGO) lesions are detected in patients with otherwise operable non-small cell lung cancer, it is controversial whether to resect them simultaneously with the primary tumor or not.
Methods: We retrospectively reviewed radiologic features and pathologic diagnoses of pure GGO lesions detected in otherwise operable non-small cell lung cancer. Forty lesions were identified in 23 patients. Four of the eight lesions that were simultaneously resected at surgery for the primary tumor turned out to be malignant. During follow-up, four lesions increased in size and were resected later. The remaining 28 lesions were considered nonmalignant because the size did not change or decreased during follow-up. All the lesions were divided into nonmalignant (n = 32) and malignant groups (n = 8), and their clinical and radiologic features were compared.
Results: There was no significant difference in clinical or pathologic findings between the two groups. Median size of the lesions in the nonmalignant group (5 mm) was significantly smaller than in the malignant group (11 mm) (p = 0.001). We tried to predict whether a lesion is benign or malignant based on its size. With a cutoff value of 8 mm, the sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 88%, 81%, 53%, 96% and 83%, respectively.
Conclusions: When a pure GGO is detected in otherwise operable lung cancer, it should be resected to rule out the possibility of malignancy if the size is greater than 8 mm. Nevertheless, if the size is less than 8 mm, we suggest that it could be closely followed up using imaging studies.