Benign Endobronchial Tumors: A Clinicopathologic Review

Abstract

Purpose: Benign endobronchial tumors are rare entities that can be difficult to diagnose because they often present with non-specific symptoms and vague radiographic findings. The current study reviews the clinical, radiologic and pathologic features, diagnosis, and treatment of patients with benign endobronchial tumors. Methods: We examined the charts of all patients who presented with biopsy-proven benign endobronchial tumors at a tertiary-care academic medical center between 1993 and 2018. Pertinent clinicopathologic and radiologic data were analyzed, with particular attention paid to treatment modalities and mean overall patient survival. Results: A total of 28 cases were identified. The most common benign neoplasm was hamartoma (37%), followed by lipoma (19%), squamous papilloma (11%), pleomorphic adenoma (7%), mucin gland adenoma (7%), papillary adenoma (3%), hemangioma (3%), neurofibroma (3%), leiomyoma (3%), and papillomatosis (3%). Cough (58%), shortness of breath (44%), and hemoptysis (15%) were the most frequent presentations. Most cases demonstrated well-defined submucosal or pedunculated endobronchial lesions with segmental pneumonia or atelectasis on imaging. Histologic diagnosis was obtained by endobronchial resection in 43% of patients, thoracoscopic lobectomy in 36%, endobronchial biopsy in 18%, and thoracoscopic wedge resections in 3%. All procedures were performed with no intraoperative or in-hospital deaths (mean overall survival: 20.2 years). Conclusion: Benign endobronchial tumors typically present as well-defined submucosal and/or pedunculated lesions, and may lead to post-obstructive complications. Endobronchial resection is the preferred strategy for diagnosis and treatment of these tumors.

Keywords: benign endobronchial lesion; endobronchial tumor; hamartoma; leiomyoma; thoracic surgery.

Figure 1

(A) Histologic sections of a mainstem bronchus lesion show a proliferation of mature cartilaginous tissue surrounded by spindle cells, consistent with a hamartoma. No mitotic figures or necrosis are appreciated, confirming the benign nature of the lesion. (B) Histologic section of an intrabronchial lesion. A thin lining of ciliated cuboidal respiratory epithelium is identified. A fascicular proliferation of smooth muscle bundles with eosinophilic and occasional fibrillar cytoplasm is seen within the tumoral lesion, finding consistent with a benign leiomyoma. (C) Histologic section of a common intrabronchial lesion recovered in our database. A lining is observed surrounding the lesion, compatible with respiratory epithelium. The lesion is composed of mature fibroadipose tissue without evidence of atypia or necrosis, consistent with lipoma.

Figure 2

Bronchoscopic imaging demonstrating (A) hamartoma and (B) leiomyoma.

Figure 3

Anatomic locations of benign endobronchial lesions of patients diagnosed and treated at Rush University Medical Center between 1993 and 2018.