We read with interest the recent paper by Koudounarakis and co-workers , who described in detail a rare case of acquired tracheal diverticulum reasonably due to a tracheal injury during a previous thyroidectomy. We would like to add that a tracheal diverticulum may rarely occur also as a late tracheotomy complication.

A 68-year-old male patient was admitted to our Department to be treated for a squamous cell carcinoma of the left retromolar region. Ten years before the patient had undergone a horizontal supraglottic laryngectomy with temporary tracheotomy for laryngeal carcinoma. During last hospitalization, computerized tomography (CT) scan of the neck incidentally revealed a right-sided, air-filled, thin-walled cystic lesion in communication with the trachea at the level of previous tracheotomy ( Fig. 1 ). At physical evaluation, a 2.5-cm firm, spongy, asymptomatic mass, deep to the healed tracheotomy scar was found hyper-extending patient’s neck. During oncological surgery for oral cavity carcinoma, the cystic lesion, in communication with the trachea, was isolated and removed. At final histopathological examination, the cystic lesion appeared to be lined by keratinized squamous epithelium without evidences of other tracheal structures ( Fig. 2 ).

Neck CT scan showing right-sided, air-filled, thin-walled cystic lesion in communication with the trachea.

Paratracheal cystic lesion lined by keratinized squamous epithelium with chronic lymphoplasmacytic chorion inflammation.

Acquired tracheal diverticulum after a routine tracheotomy has been rarely reported in the literature. Our exhaustive English language literature review disclosed to date only six cases of air-filled tracheal diverticulum after tracheotomy, present case included . On the other hand, Djamouri et al. described two cases of acquired tracheal diverticulum in patients with a history of unspecific neck surgery and Teker et al. a case of a patient treated with mediastinoscopy with node sampling and video-assisted thoracic surgery .

Only three acquired tracheal diverticula after tracheotomy occurred in adult patients, present case included , while the other three cases have been reported in children . Tracheotomy was performed a few months before tracheal diverticulum disclosure in two cases with available data , while in our case and in that reported by Chin et al. the lesion presented more than 10 years after tracheotomy. Differently, O’Neal et al. described a case of an acquired cervical tracheal diverticulum associated with a maintained tracheotomy in a 2-year-old child with congenital bilateral vocal cord paralysis .

Considering available literature, patients showed an anterior cervical mass that developed at the level of previous tracheotomy site and that was enlarging with respiratory movements or paroxysmal cough . Our patient was asymptomatic and only neck hyperextension revealed a small, firm, spongy mass, deep to the healed tracheotomy scar. Diagnosis was based on CT findings. Neck CT scan revealed an enlarged air-filled, thin-walled mass at the level of the thoracic inlet, which was in clear communication with the trachea in our case and in that described by Briganti et al. . This communication could not be clearly seen by CT scan in the case reported by Henderson et al., however a site of communication was intra-operatively identified . CT is the gold-standard imaging modality for identification and surgical planning of air-filled paratracheal cysts and could incidentally find an asymptomatic lesion, as reported in our case . Histologically, our pathologist found a keratinized squamous epithelium, probably due to a squamous metaplasia, as described by Kanemitsu et al. . Skin eversion during tracheotomy could have had a significant role in squamous metaplasia formation. Differently, the other two cases of tracheal diverticulum after tracheotomy were lined by a single layer of respiratory epithelium (acquired tracheoceles) .

In documented cases of acquired tracheal diverticulum after tracheotomy, the lesions were completely dissected and excised. Management included bronchoscopy and surgical decompression with drain insertion and pressure dressings in the tracheotomy dependent pediatric patient . A gold standard treatment protocol for this lesion has not been codified because of the rarity of this occurrence. Generally, the surgical intervention can confirm the diagnosis of tracheal diverticulum and is required when tracheal irritability occurs or when this abnormality is found in conjunction with another neck surgical procedure .

Tracheotomy is a commonly performed operation with well-known postoperative complications; tracheal diverticulum is not listed as a possible complication of tracheotomy in the major general surgery or head and neck surgery text-books .