A Malignancy-Mimicking Lung Lesion: Sclerosing Pneumocytoma

Abstract Background: Sclerosing pneumocytoma (SP) is a rare benign pulmonary neoplasm that can mimic malignancy on radiologic imaging, presenting a diagnostic challenge. Case: A 56-year-old woman was evaluated for an incidentally detected 30 mm solid mass in the the left lower lobe. PET/CT revealed increased FDG uptake (SUVmax: 5.5), and MRI showed marked contrast enhancement suggestive of a neuroendocrine tumor. Bronchoscopy revealed no endobronchial involvement. Pulmonary function was sufficient for resection. Given the lesion’s central location, imaging findings concerning for malignancy, and absence of a preoperative diagnosis, video-assisted thoracoscopic lobectomy with mediastinal lymph node dissection was performed. Histopathological and immunohistochemical analysis confirmed SP. The postoperative course was uneventful, and no recurrence was observed during 14 months of follow-up. Conclusion: SP should be included in the differential diagnosis of solitary pulmonary nodules. In patients with radiological features mimicking malignancy, anatomical resection may be required for definitive diagnosis and oncological safety.