Primary tracheobronchial amyloidosis: coronal CT scan may provide clues for early diagnosis.

Primary tracheobronchial amyloidosis (PTBA) is a localized form of amyloidosis. The clinical signs of this condition are non-specific and diagnosis before bronchoscopic examination with multiple biopsies is uncommon. We present three cases of PTBA and compare findings between the thoracic imaging and fiberoptic bronchoscopy. Radiographic findings often had uncharacteristic features. The relatively specific coronal section CT preceded findings in transverse sections, and showed an irregular mucosal surface with diffuse prominent nodes and/or calcification of the tracheobronchus, which we called the "wavy path sign". In conclusion, coronal CT scan can provide ample clues for the early diagnosis of PTBA.