Pulmonary sclerosing pneumocytoma, a rare tumor of the lung.

Pulmonary sclerosing pneumocytoma (PSP) is a rare benign pulmonary tumor. Usually diagnosed incidentally by chest X-ray or chest CT scan. We presented a case of PSP in a 50-year-old woman who was diagnosed with a nodular lesion in the right lung. Thoracotomy was used for the excision of the mass. Pathologic examination revealed no malignant cells. Immunohistochemical studies were performed. TTF-1 was (+), Napsin-A was found to be weakly (+). After surgical resection, the patient was followed up.