Flexible Bronchoscopic En Bloc Cryoextraction of Endobronchial Leiomyoma Using a 1.7-mm Cryoprobe: A Case Report with One-Year Follow-Up.

Background and Clinical Significance: Endobronchial leiomyoma is a rare benign tumor of the respiratory tract, accounting for less than 2% of all benign pulmonary neoplasms. Most cases have been treated surgically or with endoscopic modalities such as laser or rigid bronchoscopy-assisted cryotherapy. Flexible bronchoscopic cryoextraction has been rarely reported, typically with 2.2-mm probes. Small-caliber cryoprobes (1.1- and 1.7-mm) have been validated for diagnostic transbronchial cryobiopsy but not for therapeutic removal of leiomyoma. We report a case of complete removal of endobronchial leiomyoma using a 1.7-mm cryoprobe via flexible bronchoscopy, demonstrating full airway and physiologic recovery. Case Presentation: A 25-year-old never-smoking man was referred after an abnormal health-screening chest radiograph demonstrated right middle and lower lobe atelectasis. Chest CT revealed a mass obstructing the proximal bronchus intermedius. Spirometry showed reduced FEV1 and FVC with preserved FEV1/FVC ratio, consistent with central airway obstruction. Therapeutic flexible bronchoscopy (Olympus BF-1TQ290) was performed under endotracheal intubation. Initial forceps biopsies were followed by transbronchial cryobiopsy with a 1.7-mm cryoprobe, applied for five freeze-adhesion cycles. The mass detached en bloc and was retrieved without complications, resulting in complete airway recanalization and visualization of the right middle and lower lobe bronchi. Histopathology showed interlacing fascicles of bland spindle cells with cigar-shaped nuclei, positive for SMA and desmin and negative for S-100 and CD34, confirming leiomyoma. The patient was discharged the next day. At one-year follow-up, bronchoscopy and CT demonstrated no recurrence, and spirometry normalized. Conclusions: Reports combining flexible bronchoscopy with a 1.7-mm small-caliber cryoprobe for en bloc removal of endobronchial leiomyoma are rare. This technique may represent a minimally invasive option for selected cases, provided careful hemostatic planning and appropriate case selection.