r-EBUS sign and cryo-extraction of a pulmonary hydatid cyst.

Abstract

A 36-year-old female, never smoker, presented with 8-month history of persistent cough reporting no allergies, occupational or environmental exposures. Routine lab-tests were unremarkable. A non-contrast CT and PET-CT revealed an FDG avid (SUVmax 3.8), 3.5x2.8cm solid lesion adjacent to the major fissure of the right lung with no other findings reported (Fig.1). She was referred to our IP Unit after non-diagnostic bronchoscopy and CT-guided FNB. Following virtual segmentation and pathway analysis of the lesion, bronchoscopy with a 4.9mm outer diameter bronchoscope, revealed a whitish lesion obstructing a sub-sub-segmental orifice of RB8 (Fig.2). Forceps biopsies yielded acellular, non-diagnostic material by rapid-on-site-evaluation (ROSE). Radial endobronchial ultrasound (rEBUS) probe was inserted beneath the lesion to appreciate the presence of vessels prior to cryo-debulking. Interestingly, rEBUS revealed an unusual pattern of concentrical folds indicating walls of a ruptured cyst (Fig.3). Using a 1.1mm cryoprobe, the lesion was successfully removed at first attempt (5 sec freezing time) without complications apart from self-limited bleeding with no need for bronchial blocker(Fig.4). The extracted white membranes were consistent with hydatid cysts. Prophylactic corticosteroids and antihistamines were administered. Pulmonary echinococcosis was confirmed by pathology, positive serum Echinococcus IgG and presence of hooklets in bronchial washing. Patient was discharged on albendazole. Post-bronchoscopy x-ray and chest CT showed radiologic improvement (Fig.5,6). While hydatid cysts have been previously observed and removed bronchoscopically, this is the first report of rEBUS guided cryo-debulking [1,2]. rEBUS sign of concentric cystic walls may aid diagnosis, exclude presence of large vascular structures and ensure a safe cryo-extraction.