tracheobronchopathia osteochondroplastica ( to ) is a rare benign airway disease typically characterized by the presence of multiple rock - garden - like nodules in the lower trachea and upper main bronchi ( 1 ) .
because of the absence of cartilage in this region of the airway , these nodules involve the anterior and lateral walls of the trachea and the bronchus , sparing the posterior membranous wall ( 2 ) .
several reported cases have demonstrated successful surgical intervention and bronchoscopic laser therapy for advanced symptomatic patients ( 2,3 ) .
we herein report the successful bronchoscopic resection of a symptomatic localized polyp due to to using a high - frequency snare .
an 80-year - old japanese man was admitted to our hospital for the evaluation and management of multiple tracheobronchial polyposis and right middle lobe atelectasis . he had a history of polyarteritis nodosa and had been treated with corticosteroids ( prednisolone 6 mg / day ) .
chest computed tomography ( ct ) revealed diffuse calcified lesions throughout the cartilaginous regions of the trachea and bronchi , right middle atelectasis , and airway polyps ( 4 - 9 mm ) in the left trachea and the left main bronchus ( fig .
1 ) . the bronchoscopic findings showed diffuse edematous mucosal lesions with polyposis on the left side of the trachea , the right middle bronchus and the left main bronchus ( fig .
2 ) . a spirometric analysis demonstrated an obstructive impairment , and the forced expiratory volume in one second ( fev1 ) was 1.36 l , and fev1% was 43% .
a transbronchial biopsy to make a diagnosis of the airway polyp was performed , and endoscopic mucosal resection was also carried out using a high - frequency snare to improve ventilatory insufficiency .
to was pathologically confirmed in the resected submucosal cartilaginous tissue , and mature ossifications were also observed in the tissue ( fig .
after resecting the airway polyp , the spirometric data of the fev1 and fev1% improved from 1.36 l to 1.69 l and from 43% to 93% , respectively .
a : a coronal view of the chest mediastinal window shows diffuse calcified lesions throughout the cartilaginous regions of the trachea and bilateral bronchi .
noncalcified endobronchial airway polyps are also seen on the left side of the trachea and the upper side of the left main bronchus ( white arrows ) .
b : a transverse view of the chest mediastinal window demonstrates right middle lobe atelectasis and an endobronchial airway polyp with small calcified lesions ( white arrow ) in the right middle lobe bronchus .
there are no remarkable abnormal findings in the trachea ( a ) and carina ( b ) , however , bronchoscopy showed a diffuse edematous mucosa with polyposis in the trachea ( a ) , carina ( b ) , right middle bronchus ( c ) and left main bronchus ( d ) .
a : an endobronchial polyp lesion obtained from the left main bronchus demonstrated submucosal calcification , ossification and cartilage formation surrounded by chronic airway inflammatory cells .
b : an enlarged view shows the polyp lesion to consist of submucosal ossification and inflammatory cells .
the comprehensive etiology of to remains to be elucidated , however , chronic airway infections , irritant exposure , several metabolic disorders and genetic factors have been proposed to be causative factors of to ( 3,4 ) .
this patient showed typical chest ct findings ( fig . 1 ) and unusual bronchoscopic features ( fig .
long - term corticosteroid administration might be a potential explanation for the atypical bronchoscopic findings .
tajima et al . reported that bone morphogenetic protein-2 ( bmp-2 ) played an important role in nodule formation and might synergistically act with transforming growth factor 1 ( tgf-1 ) to promote an inductive cascade of to nodules ( 5 ) .
the airway polyp in our patient did not include mature ossifications in contrast to the previously reported cases ( 2,4 ) , and the long - term corticosteroid administration in this patient might be related to these pathological atypical findings , such as the suppression of calcified lesion formation .
however , there has so far been no report describing the effects of corticosteroids on initiating and enlarging airway polyp formation ; thus , further studies are necessary to clarify the mechanism of airway polyp formation and effective treatment .
reported that chronic airway inflammation might be an important factor in the formation of to , and they discussed the potential clinical effects of inhaled corticosteroids to improve the symptoms in patients in the early stage of this disease ( 3 ) .
no guidelines have yet been established for the management of to , and systemic or inhaled corticosteroid treatment might be one of treatment choices for to without any problematic clinical symptoms , as seen in the present patient . in conclusion , we herein reported a rare case of to accompanied by unusual bronchoscopic features , such as multiple tracheobronchial polyposis , which was successfully treated using a high - frequency snare .
to is a benign disorder , however , to may cause various clinical symptoms and spirometric impairments that necessitate the resection of airway polyps .
physicians should therefore be aware of this disease and its clinical symptoms and include it in the differential diagnosis .
 tracheobronchopathia osteochondroplastica ( to ) is a rare benign airway disease that is characterized by the presence of multiple rock - garden - like nodules on bronchoscopy . to is a slowly progressive disease of the trachea and major bronchi , which is typically characterized by such symptoms as a persistent nonproductive cough , dyspnea and wheezing . 
 the clinical features of to are variable , and asymptomatic patients may incidentally be diagnosed during the work - up for other diseases . 
 we herein report a rare case of to accompanying multiple tracheobronchial polyposis in which bronchoscopic resection of the airway polyp using a high - frequency snare was successfully performed . 