Stening 
Osteochondroplastic tracheopathy: tracheal aspect very different from its usual anatomical conformation. Multiple hard nodular excrescences, irregularly distributed over the tracheal cartilages, upholstered by normal mucosa. Osteoplastic tracheopathy is an infrequent and asymptomatic condition. Alejandro Posadas Hospital
Photograph of a tracheal pseudomembrane extracted under rigid bronchoscopy, in a patient with obstructive symptoms and a history of recent orotracheal intubation.
Trachea in “saber scabbard”. Notable reduction of its transverse diameter, due to the compression exerted by paratracheal adenomegalies of group 2 and 4. The mucosa is thickened by regular edema.
Severe distortion of the precarinal trachea by compression that elevates the folds and deforms the entrance of the main bronchi. The carina, although very asymmetric, remains fine.
On the compression of the posterior wall protrudes a submucous and smooth protrusion. Towards the bottom of the image, one can guess the great widening of the tracheal carina.
Low light in “half moon”, by strong compression on the tracheal posterior wall.
Severe compression on the tracheal posterior wall that advances it toward the light. General and regular edema of the mucosa.
Slight lateral compression and folds that curve and accentuate as a sign of affection adjacent to the posterior tracheal wall.
Actinic necrosis: The trachea presents a reduction of its transverse diameters as a consequence of the acute necrosis of its mucosa, which has allowed the detachment of the tracheal rings at their ends. The organ is disordered in inspiration, narrowing its posterior mucous membrane and deepening intercartilaginous spaces.
Reduction of tracheal light of combined cause. Visible right posterolateral compression and intramural lesion in the opposite wall that begins to protrude towards the light.