Laryngeal papillomas in children are a frequent condition caused by the human papilloma virus (HPV). Owing to the molecular hybridisation technique, nearly 77 types of HPV have been isolated; type 6 and type 11 are responsible for benign changes in the larynx and respiratory tract. Types 16, 18, 31, 45 of HPV are rarely seen, being responsible for progressive transformation in the papilloma into malignant tumours (5, 7, 8).

Recurrent respiratory papillomatosis (RRP) is associated with exophytic lesions of the airway. Clinically, laryngeal papilloma may differentiate as juvenile-onset laryngeal papilloma and adult-onset laryngeal papilloma, but it is likely that the natural history of papilloma growth is one continuum of age distribution, usually with exacerbations and remissions. Despite of its benign histology, RRP presents potential morbidity due to severity of involvement of the airway and to the risk of malignant degeneration. It is often difficult to treat because of its tendency to recur and spread throughout the respiratory tract. Juvenile papilloma is characterised by massive growth, frequently multifocal, with a tendency to spread causing lesions and involving healthy mucous membranes. Papillomas also show multiple recurrences, but often a regression of the condition is observed at puberty. Frequent recurrence of this condition and various periods of remission are connected with the existence of the virus in a latent form, periodically reactivated.

HPV shows a predilection to infect sites where ciliated columnar and squamous epithelia are juxtaposed. This explains the frequent involvement of the false vocal folds, the upper and lower margins of the ventricle, and the lower surface of the true vocal folds. Less frequently, lesions are found on the nasopharyngeal surface of the soft palate, the mid-zone of the laryngeal surface of the epiglottis, and mucosa of the carina. In tracheotomized patients, papillomas are often encountered at the stoma. It is postulated that the junction of ciliary and squamous epithelia is a location particularly prone to infection with latent vital forms. An endotracheal tube may play the same role in the mechanical dissemination or implantation of papilloma virus as a tracheotomy in this setting, through the interruption of the continuous respiratory mucosal surface. Tracheotomy is a procedure which accelerates the dissemination of lesions within the respiratory tract (4). According to some authors, lower respiratory tract papillomatosis concerns 1-4% of patients with juvenile laryngeal papillomatosis. The prognosis in these cases is always serious.

At the Department of Paediatric Otorhinolaryngology of the Medical University in Warsaw, we have treated 98 children with laryngeal papillomatosis in the period between 1980 and 2005. In four children papilloma of the trachea, bronchi and lung was diagnosed. The period of follow-up was 8-16 years.

Papilloma of the larynx, trachea and bronchi was diagnosed during laryngotracheobronchoscopy. These lesions were removed in classical papillotomy using rigid bronchoscope and the Kleinsasser arrangement and using argon plasma coagulation in one child. All children had a chest X-ray. In two children combined surgical and pharmacological treatment with interferon alpha was applied; one of these children underwent chemotherapy in another medical centre.

In all four children (two girls and two boys) a clinical diagnosis of laryngeal papillomatosis was made between 1 and 3 years of age: papilloma in the trachea was recognised 3-7 years later, and characteristic radiological lesions in the lungs were present 4-8 years after establishing the initial diagnosis. Three children died and one has chronic respiratory insufficiency. The reason for first endoscopic examination of the larynx was progressing hoarseness, aphonia, laryngeal stridor and progressive respiratory disturbances. In all patients there was recurrent pneumonia, confirmed by chest X-rays. Characteristic cystic lesions or small nodules in the lungs appeared in the first patient at 5 years of age, in the second at 11 years of age and in the third and fourth at 5 and 3 years, respectively. In all children the size of the cysts ranged from 5 to 50 mm. Cysts were diagnosed 4-8 years after establishing the diagnosis and about 1 year after diagnosing papilloma in the larynx. Their number and size increased during observation, with often associated inflammatory symptoms, parenchymal thickening of lung tissue and fluid levels in cysts in chest X-rays. In all children the presence of cysts and nodules in the lungs was preceded by non-characteristic but particularly important lesions, being recurrent pneumonia in three children approximately 1 year after establishing the diagnosis of laryngeal papillomatosis, emphysema in two children, and atelectasis of the lung in one child. Computerised tomography of the chest confirmed the presence of cysts and nodules in the lung tissue, and changes typical for chronic pulmonary diseases.

Multiple papillotomies indicated a progression of papillomatous lesions in the trachea and bronchi and intervention frequency increased. Three children died at the 13, 9 and 7 years of age following chronic respiratory insufficiency.

Depending on the site and extent of papillomatous lesions, the following symptoms may dominate: hoarseness (in 45% cases), laryngeal stridor, expiratory-inspiratory dyspnoea, aphonia, recurrent pneumonia, recurrent laryngitis or chronic cough (5). These last symptoms – not particularly specific for papilloma – may delay appropriate management because patients are diagnosed with asthma, allergy or chronic laryngitis. In about 4-5% of cases papilloma may affect the trachea; in these cases pulmonary lesions are detected in about 1% of cases. In our material, children with papillomatosis of the trachea and bronchi constituted 4.4% of the group. The prognosis in cases where papilloma is present in the trachea, bronchi and lung tissue is serious and the mortality in these cases is high. In an examined group of four children we noted three deaths because of chronic respiratory insufficiency.

Radiological abnormalities found in cases of lower respiratory tract papillomatosis are connected with hyperplastic papillomatous lesions in the pulmonary alveoli and in lung parenchyma. Cysts in the lungs increase concentrically and the walls of pulmonary alveoli become their walls causing destructive lesions in pulmonary tissue (6, 9). Laryngeal papilloma grows below the larynx usually continuously to the main bronchi. This location may suggest that papilloma detached during a surgical procedure or by coughing can be carried by aspiration to the lower respiratory tract. Thus, aspirated papilloma may be expectorated or removed, or may grow in pulmonary tissue. It is possible that cells or clumps of cells are being aspirated into the lower respiratory tract continuously. If the parenchyma of the lungs is involved with papillomatous lesions, the patient will have symptoms of restrictive pulmonary disease connected with obturation of the upper respiratory tract. All children required complex laryngological and pulmonological care.

The presented data show how difficult the treatment of extensive papillomatous lesions is when lung tissue is also involved. Until now, no causal treatment has been found to be totally effective in the eradication of juvenile laryngeal papillomatosis. In some laryngological centres combined surgical treatment (laser, classical papillotomy, argon plasma coagulation, photodynamic therapy, microdebrider) and pharmacological treatment is used. In the described material a combined surgical and pharmacological (alpha-interferon) treatment was used without any positive effects (1, 2, 3). Argon plasma coagulation was used in one patient.

Our equipment consisted of an argon gas source and high-frequency surgical unit (APC 300 ERBOTOM ICC 350-ERBE) and a rigid probe with a ceramic nozzle fitted at 0^o or 90^o relative to the probe axis. Different coagulation times were used, ranging from 1 to 3 s repeated a few times. The flow rate of the argon gas during coagulation was set at 1.0-1.2 l/min. All interventions were performed under general anaesthesia. In the literature, APC and laser therapy has been compared. APC does not require protection measures needed with laser. Tissue carbonisation, produced by laser, does not occur with APC. Of course, it is not a perfect method. Although argon does not react with other gases, it can eliminate oxygen from the airways, and therefore it is necessary to monitor blood oxygenation both during the operation and in the postoperative care period.

The prognosis in cases when papillomas are in the trachea, bronchi and lung tissue is serious. Recurrent pneumonia in children with diagnosed laryngeal papillomatosis may suggest the spread of the disease into lung tissue. All children with recognised laryngeal papillomatosis should be given chest X-rays. Surgical management of recurrent respiratory papillomatosis is challenging. The treatment of papillomatous lesions in the pulmonary tissue is still a difficult problem.