The value of CT scan-guided biopsy in evaluation of ground-glass opacity.

We read with interest the article by Dr Chang and colleagues 1 in CHEST (January 2013) about the management of ground-glass opacities (GGOs). Their data indicate that the strategy of longterm follow-up and selective surgery was appropriate. However, we do not entirely agree with their ideas. We offer a third choice of CT scan-guided biopsy to solve the long-standing issue. Previous studies have shown that a solid component of GGOs is a remarkable characteristic of malignancy. 2 , 3 However, it is diffi cult to identify GGOs without a solid component. We congratulate the authors for the diagnosis of 11 cases of malignant GGOs, but was there other malignant neoplasm in the remaining followups? Other investigators have reported that the malignancy rate of GGOs without a solid component is 18%. 3 It should be noted that the rate of malignant GGOs in the study by Chang et al 1 was only 10% (11 of 122). In the evaluation of GGOs, benign lesions usually resolved partially or completely by CT scan recheck 3 months later. 4 In our practice, when the nature of GGOs, especially those with a relatively large size, is still uncertain at 3 months, CT scan-guided biopsy is recommended to patients. In our experience, the success rate of biopsy is relatively high when the diameter of a GGO is . 7 mm. Our biopsy cases all produced pathologic results, which were consistent with the subsequent results of surgical specimens. All these cases were adenocarcinoma or bronchioloalveolar carcinoma. In a study by Kim et al, 5 CT scan-guided biopsy was also reported as effective in giving value to the nature of GGO, with a sensitivity of 93% and an accuracy of 91%. Therefore, we recommend that after a short-term follow-up, CT scanguided biopsy be given as a choice for the evaluation of GGO with a relatively large diameter.