Sequential EBUS-Guided Fine Needle Aspiration and Transbronchial Cryobiopsy for the Diagnosis of a Giant Mediastinal Lipoma: A Novel Intraoperative Pivot Strategy.

Mediastinal lipomas are extremely rare, comprising only 1.6%-2.3% of all primary mediastinal tumours, with fewer than 200 cases reported worldwide. The diagnostic imperative is excluding well-differentiated liposarcoma via MDM2 fluorescence in situ hybridization (FISH), which has traditionally required surgical resection for adequate tissue sampling. We report the first described use of sequential EBUS-guided fine needle aspiration (FNA) and intraoperative pivot to transbronchial cryobiopsy for definitive diagnosis of a giant mediastinal lipoma. A 61-year-old asymptomatic male was incidentally found to have a 6 × 7 × 13 cm anterior mediastinal mass on CT chest. EBUS-FNA with a Cook 22-gauge needle yielded only minute fat-containing tissue on rapid on-site evaluation (ROSE), insufficient for diagnosis. The procedure was immediately transitioned: an Olympus ViziShot 21-gauge needle created a transbronchial tract through which a cryotherapy probe obtained multiple adequate tissue cores, confirming mature adipose tissue on histopathology. MDM2 FISH demonstrated no gene amplification, confirming benign lipoma. This case establishes a practical intraoperative rescue strategy for lipomatous mediastinal lesions where FNA yield is insufficient. The patient subsequently underwent surgical resection; final pathology confirmed benign lipoma, fully concordant with the bronchoscopic diagnosis.