Radiology Resident Case of the Week
When laryngeal papillomatosis spreads to the lungs, it slowly grows and destroys lung. The most common presentation in this stage is recurrent upper airway obstruction; less commonly, the patient may experience symptoms of restrictive lung disease.
Etiology/Pathophysiology:
Laryngeal papillomatosis, the most common tumor of the larynx in children, is caused by HPV (Human Papilloma Virus). 2/3 of those affected are children under the age of 4 years, some of whom acquire it through the birthing process. The lesions typically remain confined to the larynx, but may seed the trachea and bronchi by respiratory spread. They typically regress after puberty. Involvement of the pulmonary parenchyma (also by respiratory seeding) occurs in less than 1% of cases, and it carries a poor prognosis.
Pathology:
In the larynx, the lesions may be cauliflower-like, pedunculated or sessile. In the pulmonary parenchyma, they are first solid, then cystic lesions. The walls of the cysts are typically 2-3 mm. As they slowly grow, they coalesce. Microscopically, they are squamous cell proliferations (papillomas) with central cavities containing debris and/or air. Malignant trasnsformation appears to be rare.
Miscellaneous:
Laryngoscopy has been used to diagnose and treat--simply pulling the papillomas off with forceps, but a rapid local recurrence is common. Recently, cryosurgery and LASER surgery have been advocated. Any of these treatments, however, may carry an increased risk of pulmonary spead. Systemic bleomycin may be helpful.
Imaging:
Laryngeal papillomatosis can be diagnosed by plain film.
These exophytic masses are easily seen on CT.
Pulmonary papillomatosis is best evaluated with CT. The early stage of small, homogeneous, round solid lesions is usually seen in conjunction with older lesions which are typically 2-3 cm cystic spaces with 2-3 mm thick walls; since they coalesce as they grow, they may not be round, but rather lobulated. Debris may be seen within the cysts.
DDx:
Emboli, Abscesses, TB, pneumatocele, squamous cell carcinoma metastases.
Key references:
Nelson's Textbook of Pediatrics, 13th edition, Behrman and Vaughan
Caffey's Pediatric X-ray Diagnosis, 8th edition, Silverman
Kramer, et al, AJR, '85, 144:687
ACR Code:
Keywords:
papillomatosis, laryngeal papillomatosis, laryngotracheal papillomatosis, pulmonary papillomatosis.