ABSTRACT
Objective Sclerosing pneumocytoma (SP) is a rare benign tumor of the lung. This study investigates the CT and PET/CT features of 52 patients with sclerosing pneumocytoma (SP), summarizes their imaging features and provide reference for improving the accuracy of SP imaging diagnosis.Methods The clinical and imaging data of 52 patients with SP confirmed by operation and pathology in the Affiliated Hospital of Nanjing University of Traditional Chinese Medicine and the First Affiliated Hospital of Nanjing Medical University from January 2010 to March 2018 were analyzed retrospectively，and the imaging features of the disease were analyzed and summarized. Among 52 SP patients, 46 were female and 6 were male, with an average of 50.7±12.6 years old.Results ①Morphological characteristics: all were round or round-shaped solitary nodules or masses in the lung. The average diameter of the tumor was 22.2±15.4 mm. 39 lesions had smooth edges and 13 had shallow edge lobulation sign; ②Predilection sites: 33 of the cases were closely attached to or adjacent to the pleura, and there was no preponderant distribution of the lobe; ③Density: The density of the lesion was homogeneous. 8 cases had coarse calcifications at the edges or in the lesions; ④Enhancement features: 26 cases showed moderate to marked enhancement, only 6 cases were mild enhancement; ⑤Features around the tumor: "vascular adhering sign" in 21 cases, "tail sign" in 7 cases, "air crescent sign " in 5 cases, "localized emphysema" in 4 cases, "halo sign" in 11 cases, "bird egg-bird nest sign" in 5 cases, 4 cases of secondary bronchiectasis; ⑥Associated tumors: 3 cases of invasive lung adenocarcinoma, 3 cases of lung adenocarcinoma in situ, 2 cases of pulmonary atypical adenomatous hyperplasia, 1 case of pulmonary tiny inflammatory nodule; 2 cases of esophageal cancer associated, 1 case of invasive thymoma, 1 case of large mature ovarian cystic teratoma; ⑦PET/CT characteristics: 18F-FDG standard uptake value in tumor increased to different degrees, the average of SUV max value was 4.4±3.2.Conclusion The innovation of this research: SP is shown as solitary circular or circular-shaped blood-rich nodules in the lung, often under the pleura, especially the mediastinal pleura and lobar pleura. There is no lobar distribution advantage; SP calcification is uncommon, among which the calcification at the margin of the tumor was more common. "Air crescent sign", " Halo sign" and " Bird egg-bird nest sign" have high diagnostic value for SP.