Mobile Cone-Beam CT-Guided Transbronchial Cryobiopsy of a Penicillium Granuloma via the Right Post-Eparterial Bronchus.

A right post-eparterial bronchus (PEB) is a rare anatomical variant where an accessory bronchus arises inferior to the standard right upper lobe bronchus to supply the right upper lobe (RUL). We present a case of a 13 mm solitary RUL nodule in a 36-year-old immunosuppressed patient, uniquely supplied by a displaced PEB. Successful access was achieved using an ultrathin bronchoscope (UTB) due to the PEB's narrow lumen and acute angulation. The lesion was localised with radial endobronchial ultrasound, and definitive tool-in-lesion confirmation was obtained using a mobile Cone Beam CT system. Cryobiopsy revealed a non-caseating granuloma, with fungal culture identifying Penicillium species. This case highlights the essential role of advanced guided bronchoscopy techniques-specifically UTB navigation and intra-procedural 3D imaging-in successfully accessing and diagnosing infective pulmonary lesions situated in rare, anatomically complex airways, which may be susceptible to infection due to impaired sputum clearance.