Clinical characteristics of resected solitary ground-glass opacities: Comparison between benign and malignant nodules

Background The management of ground-glass opacities (GGOs) depends mainly on personal experience. In clinical practice, benign GGOs are not rare in resected specimens, for which operations may be avoided. We retrospectively compared the clinical features of resected GGOs to identify differential diagnostic characteristics. Methods Among 1456 patients with suspected malignant GGOs who underwent surgical resection, 105 patients (35 with benign GGOs and 70 matched controls with malignant GGOs) were included. Clinical characteristics, including demographics and radiologic, surgical and pathologic characteristics, were collected. Results The smoking index (P= 0.044), frequency of coughing (P= 0.026), GGO size (P= 0.003), size change during follow-up (P= 0.011), location (P= 0.022), presence of air bronchogram sign (P= 0.004), distance to the pleura (P= 0.021) and positron emission tomography/computed tomography (PET/CT) appearance (P= 0.003) showed significant differences between the benign and malignant groups. Pathologically, the resected benign GGOs included focal fibrosis (17), inflammation or infection (seven), lymphoproliferative disorder (one), hamartoma (three), inflammatory myofibroblastic tumor (two), hemangioma or vascular malformation (two), endometriosis (two) and pulmonary cyst (one). Conclusions A higher smoking index, coughing, larger size, similar or increased size during follow-up, location in the upper and middle lobes, air bronchogram sign on CT, lesion margin to pleura distance over 1 cm, and malignant tendency on PET/CT reports were associated with malignant GGOs. Relatively active surgical interventions could be considered for GGOs highly suspected of malignancy.