Objectives/hypothesis

Recurrent respiratory papillomatosis (RRP) of the central airways requires removal to potentially reduce recurrence and risk for malignant transformation. Analogous to the principles of treatment for early lung cancer, a precise determination of the extent of cartilage invasion could help guide therapeutic decisions and monitor response to treatment. The purpose of this study was to determine whether a bronchoscopy platform comprised of white light bronchoscopy (WLB), endobronchial ultrasound (EBUS), and optical coherence tomography (OCT) could identify layered microstructure of RRP and underlying cartilage.

Study design

Case study.

Methods

A bronchoscopy platform consisting of commercially available WLB, EBUS using a 7.5 MHz convex probe (BF-UC 160F; Olympus Optical Co. Ltd, Tokyo, Japan), and a time-domain OCT with front imaging and inside actuation (Niris Imaging System; Imalux Corp., Cleveland, OH) was used in a patient with tracheal stenosis from RRP. Findings are compared with results of histology and the characteristics of imaging modalities are discussed.

Results

WLB revealed tracheal pedunculated lesions. EBUS showed a 1-cm hypoechogenic density corresponding to the papilloma, visualized above a hyperechogenic density corresponding to tracheal cartilage. There was no sonographic evidence of cartilage disruption or adjacent lymphadenopathy. OCT revealed a layer of heterogeneous light backscattering suggesting the mucosal papilloma, and a layer of high-degree scattering, corresponding to the central fibrovascular core noted on histology.

Conclusions

Layered microstructures of RRP and underlying airway cartilage can be identified using a combination of acoustic and optical bronchoscopic imaging modalities with different resolution and depth of penetration characteristics.