To analyze the clinical features of benign pulmonary nodules (≤ 2 cm in diameter), and to improve the accurate diagnosis of pulmonary nodules.

The clinical data of patients with benign pulmonary nodules accepted by Zhongshan Hospital of Dalian University from 2013 to 2018 were analyzed, and the clinical data were compared with those of patients with malignant pulmonary nodules at the same period.

There were 104 patients with benign pulmonary nodules in total (with a benign rate of 22.7%). After pathological diagnosis , 43 cases of organizing pneumonia, 17 cases of granuloma, 14 cases of hamartoma, 14 cases of atypical adenomatous hyperplasia (AAH), 7 cases of lymph node hyperplasia, 6 cases of inflammatory pseudotumor, 2 cases of sclerosing pulmonary cell tumor and one case of tuberculous granuloma complicated with AAH were found. Among the 104 patients, 39 patients were asymptomatic; 33 cases complained of chest pain, 13 cases of cough, 11 cases of cough and sputum, 7 cases of chest tightness and 1 case of fever. After the average preoperative observation time of 7 months (from 1 week to 6 years), 17 pulmonary nodules enlarged or increased in density; blood tumor markers increased slightly in 26 patients. The imaging findings on CT showed that 19 cases were with irregular nodular morphology, 20 cases with spicule sign, 11 cases with lobulation, 16 cases with pleural indentation, 11 cases with calcification, 9 cases with vessel convergence, 9 cases with vocule sign, 8 cases with pleural thickening, and 7 cases with air bronchogram. Compared with 354 cases of malignant nodules (primary lung cancer) operated at the same time, more benign nodules were solid (P ≤ 0.001), with a diameter ≤10 mm (P = 0.003) and the incidences of pleural indentation and vessel convergence were significantly lower (P ≤ 0.001, P = 0.013). Both benign and malignant pulmonary nodules were more common in upper lobes.

The imaging characteristics of benign and malignant pulmonary nodules are similar while vascular clustering and pleural indentation are more differentiated . Greater patience should be given to solid pulmonary nodules( ≤10 mm in diameter).