SESSION TITLE: Miscellaneous Cases IV
SESSION TYPE: Medical Student/Resident Case Report
PRESENTED ON: Monday, October 28, 2013 at 04:15 PM - 05:15 PM
INTRODUCTION: Probe-based confocal laser endomicroscopy (pCLE) can be used with electromagnetic navigational bronchoscopy (ENB) to guide transbronchial biopsies (TBBx).
CASE PRESENTATION: 58-year-old woman with a history of rheumatoid arthritis (RA) on methotrexate and adalimumab presented with an abnormal CT. She is a life-long non-smoker. Initial CT showed ground-glass-opacities and bronchiectasis in the right middle lobe and lingula. Patient declined bronchoscopy. Labs including quantiferon and fungal serologies were negative. The changes were attributed to methotrexate therefore this was held. Follow-up imaging over several months documented stability. A later CT showed a new 1.6cm sub-solid nodule in the right upper lobe. Patient was still on adalimumab and she agreed to ENB with pCLE. Once the area of the lesion was accessed using ENB, the pCLE probe was placed through the extended working channel (EWC) where microscopic images of the alveoli were obtained. Initial images showed normal appearing alveoli with well-organized elastin fibers. The EWC was then slightly repositioned and the probe again used for imaging this time showing dense, disorganized elastin fibers. Biopsies were taken that showed eosinophils and histiocytes that were CD1a positive supporting a diagnosis of pulmonary Langerhans cell histiocytosis (PLCH).
DISCUSSION: PLCH is an uncommon disorder and can manifest as single-system disease affecting the lungs, skin or bones. PLCH is associated with cigarette smoking in >90% of cases, however reports describe occurrences in non-smokers as well. The diagnosis usually requires a surgical biopsy with TBBx yields ranging from 10-40%. Recent data show the use of “guided” technology with ENB ± radial-endobronchial ultrasound (R-EBUS) can improve TBBx yield (14-63% vs. 59-88%). pCLE uses a 488nm laser in a 1.4mm flexible miniprobe containing 30,000 microfibers to produce a field of view of 600μm with a 50μm depth of penetration allowing for visualization of the elastin fibers of the airways and distal lungs in vivo. This technology can be used in conjunction with ENB in a similar fashion to R-EBUS to guide TBBx and perhaps be used to obtain diagnostic information directly. Currently there are no clear definitions of what normal/abnormal tissue looks like using pCLE nor has the elastin appearance in specific pathologies been elucidated. This is currently being investigated and a lung registry for pCLE images is forthcoming.
CONCLUSIONS: This case shows that pCLE can be used to guide TBBx to improve diagnostic yield.
Reference #1: Tazi A. Adult pulmonary Langerhans cell histiocytosis. Eur Respir J 2006;27:1272-1285.
Reference #2: Benčić D, Smojver S, et al. Progressive form of pulmonary Langerhans’ cell histiocytosis in a female adult non-smoker. Respirology 2003;8:525-528.
Reference #3: Wang MJS, Nietert PJ, Silvestri GA. Meta-analysis of guided bronchoscopy for the evaluation of the pulmonary nodule. Chest 2012 Aug;142:385.
DISCLOSURE: Adam Wellikoff: Consultant fee, speaker bureau, advisory committee, etc.: Mauna Kea Technologies - Advisory Board The following authors have nothing to disclose: Justin Ardoin, Mario Cole, Robert Holladay
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