Sclerosing pneumocytoma: Case report of a rare endobronchial presentation

Abstract

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.

Figure 1

CT Chest demonstrating (A) 2 cm smoothly marginated nodule in the right upper lobe posterior segment. This lesion was found to have radiographic evidence of an (B) endobronchial component (yellow arrow).

Figure 2

PET/CT showing mild PET avidity associated with right upper lobe nodule (yellow arrow).

Figure 3

Pathologic findings: sclerosing pneumocytoma in an endobronchial biopsy. A. Sheets of cytologically bland neoplastic cells fill the bronchial mucosa (arrowheads, hematoxylin-eosin, 10×). Sclerotic (long black arrow) and hemorrhagic (short black arrow) areas are appreciable, even in this small sample. White arrow: respiratory epithelium. B. The neoplastic cells are positive for TTF-1 (10×). White arrow: respiratory epithelium.