DIAGNOSIS AND DIFFERENTIAL DIAGNOSIS OF SCLEROSING PNEUMOCYTOMA, HAMARTOMA, LUNG CANCER AND OTHER SOLID PULMONARY NODULES

Background: Solid pulmonary nodules are frequently encountered in thoracic imaging, and accurate differentiation between benign and malignant lesions remains challenging. Pulmonary sclerosingpneumocytoma (PSP) and pulmonary hamartoma (PH) are benign entities that may mimic lung cancer on computed tomography (CT). Objective: To evaluate and compare the clinical and CT imaging characteristics of PSP, PH, and lung cancer, and to identify distinguishing CT features that aid in preoperative diagnosis. Materials and Methods: This retrospective study included 93 patients (31 PSP, 31 PH, and 31 lung cancer) treated at Shanghai Pulmonary Hospital between September 2013 and December 2023. All diagnoses were histopathologically confirmed following surgical resection. Demographic data, clinical features, and CT characteristics were analyzed using SPSS version 23. Statistical significance was set at p< 0.05. Results: PSP predominantly affected middle-aged females (female-to-male ratio 14.5:1) and non-smokers (96.8%). PH showed a near-equal gender distribution, while lung cancer was more common in older males. PSP nodules were typically round or oval with smooth margins and higher median CT attenuation (28.9 HU), whereas PH lesions were more commonly lobulated with lower attenuation values (median 7.58 HU). Lung cancer nodules frequently demonstrated spiculation, irregular margins, and the lowest median CT values (–4.4 HU). Significant differences were observed among the three groups in age, gender, smoking status, nodule morphology, margin characteristics, and CT attenuation (p< 0.001). Conclusion: CT features—particularly nodule shape, margin, and attenuation—combined with clinical parameters such as age, gender, and smoking history, play a critical role in differentiating PSP, PH, and lung cancer. While imaging findings can guide diagnosis, histopathological examination remains the definitive diagnostic standard.