Sclerosing pneumocytoma Case report of a rare endobronchial presentation

Rationale: Sclerosing pneumocytoma is a rare benign lung neoplasm seen in middle aged adults with a female predominance. Originally thought to be vascular in origin, this rare entity is now understood to be epithelial in nature. On imaging, sclerosing pneumocytoma manifests as a well circumscribed nodule or mass, often juxtapleural in location. On histopathology, sclerosing pneumocytoma is composed of cuboidal surface cells and round stromal cells, both of which show nuclear staining for thyroid transcription factor-1 (TTF-1). Here we review the existing literature on sclerosing pneumocytoma and present a case of sclerosing pneumocytoma in a highly unusual endobronchial location. Patient concerns: This case is a 43 year old woman who presented with chronic cough. Diagnosis: Imaging revealed a right upper lobe nodule with an endobronchial component. Interventions and outcomes: Endoscopic biopsy was performed, and pathologic diagnosis was confirmed. Lessons: Although extremely rare, endobronchial presentation of sclerosing pneumocytoma is possible, and should remain on the differential for patients with endobronchial pulmonary lesions. Pathologic tissue analysis is necessary to confirm this uncommon diagnosis.