To analyze the clinical, radiological, laboratory, and histopathological characteristics of indeterminate pulmonary nodules that were highly suspected of malignancy preoperatively but were confirmed as benign by postoperative pathology, and to provide evidence for improving the accuracy of preoperative diagnosis and reducing unnecessary surgical intervention.

A total of 271 patients with pulmonary nodules who were preoperatively suspected of having malignant lesions, underwent surgical resection, and were pathologically confirmed to have benign pulmonary nodules after surgery at our hospital, between January 2020 and December 2024 were retrospectively included. Their clinical baseline characteristics, radiological findings, laboratory results, and pathological data were systematically analyzed.

During the 5-year study period, a total of 13, 201 surgical resections for pulmonary nodules were performed at our hospital, including 961 preoperatively indeterminate pulmonary nodules (7.28%). The 271 patients included in this study were pathologically confirmed to have benign lesions after surgery, accounting for 2.05% of all pulmonary nodule resections during the same period and 28.20% of all preoperatively indeterminate pulmonary nodules. Among the 271 patients, pulmonary nodules were mainly detected during routine health examinations in 166 patients (61.25%), followed by symptom-related detection in 58 patients (21.40%) and incidental detection during evaluation for other diseases in 47 patients (17.34%). Radiologically, multiple nodules were observed in 213 patients (78.60%) and solitary nodules in 58(21.40%); solid nodules were found in 240 patients (88.56%), whereas mixed ground-glass and pure ground-glass nodules were found in 31 patients (11.44%). Nodules were located in the right lung in 165 patients (60.89%) and in the left lung in 106(39.11%). The maximum nodule diameter was >1.0 cm in 162 patients (59.78%) and ≤1.0 cm in 109 patients (40.22%). Among radiological signs suggestive of malignancy, lobulation was the most common, occurring in 101 patients (37.27%), followed by spiculation in 86 patients (31.73%), pleural adhesion in 78 patients (28.78%), and the vascular penetration sign in 68 patients (25.09%). Lymphadenopathy was present in 87 patients (41.83%). PET/CT showed an increased SUVmax in 195 patients (71.96%); among them, 81 patients had an SUVmax ≥2.5 (41.54%), and 114 patients had an SUVmax <2.5 (58.46%). Postoperative pathology showed inflammatory lesions in 184 patients (67.89%), among which granulomatous inflammation accounted for 116 cases; confirmed tuberculosis and fungal infection accounted for 39 cases (33.62%)and 15 cases (12.93%), respectively. Among benign tumors, hamartoma was the most common type, with 36 cases (55.38%), followed by pulmonary sclerosing pneumocytoma in 18 cases (27.69%). Elevated fasting blood glucose was identified in 88 of the 271 patients, with an overall incidence of 32.47%. The incidence of elevated blood glucose was significantly higher in the inflammatory lesion group than in the non-inflammatory lesion group(38.59%比19.54%, P=0.002).Surgical procedures included thoracoscopic wedge resection in 151 patients (55.72%), segmentectomy in 70 patients (25.83%), and lobectomy in 50 patients (18.45%).

Benign pulmonary nodules surgically resected due to preoperative suspicion of malignancy were predominantly solid and multiple, and frequently exhibited imaging features suggestive of malignant nodules. Postoperative pathology most commonly revealed inflammatory lesions, particularly granulomatous inflammation. Abnormal glycemic status was not uncommon in this patient population, suggesting that, in addition to routine imaging assessment and follow-up, glycemic status should also be considered during the preoperative differential diagnosis. Comprehensive evaluation may help optimize clinical decision-making and reduce unnecessary surgical intervention.