Summary: A 17-year-old male with
known juvenile recurrent respiratory papillomatosis, due to HPV (human
papilloma virus) types 6 and 11, presented with exacerbation of cough and
dyspnea. He had undergone several endoscopic procedures for resection and laser
ablation of the papillomas and had been treated with intravenous cidofovir, an antiviral drug, with some
improvement. However, he recently developed mediastinal and right hilar
adenopathy, which was biopsied, revealing follicular hyperplasia without
malignancy. He is being followed with multidetector computed tomography (MDCT)
scans of the chest and airway to evaluate the status of his tracheobronchial papillomas,
pulmonary cavities, and bronchiectasis.
Diagnosis
Recurrent tracheobronchial papillomatosis with
pulmonary involvement due to HPV types 6 and 11.
Findings
A CT examination was performed with a Somatom
Definition AS 64 scanner (Siemens, Erlangen, Germany). The CT scan revealed
multiple polypoid masses protruding into the lumen of the trachea, consistent
with tracheal papillomatosis (Figure 1). The largest of the lesions measured
approximately 6 mm. CT also showed a 5.0 x 3.0 cm right infrahilar mass with
consolidation in the right lower lobe distal to this mass, representing
postobstructive pneumonitis (Figure 2). Multiple cavitary lesions with thick,
irregular walls and multiple nodules were also observed in both lungs (Figure 3
and 4).
Discussion
Recurrent respiratory papillomatosis is the most
common benign tumor of the larynx in childhood, caused by infection with human
papillomavirus (HPV), most commonly types 6 and 11.1,2 The exact
mode of transmission is unclear and is likely variable depending on the age of
the patient at presentation. In neonates and children, the likely route is
direct exposure of the neonate to the virus in the birth canal during delivery.
Among adults, the disease may be associated with oral-genital contact.1
Affected children usually present with hoarseness and occasionally with
stridor, cough, or recurrent pneumonia. The disease is characterized by benign
epithelial tumors of the airway, which most frequently are limited to the
laryngeal and subglottic areas. Involvement of lower airways and lungs is rare.
In 4% to 17% of patients, the distal trachea and bronchi are involved, and in <1%
to 5% of patients, there is pulmonary involvement.3 Malignant
transformation into squamous cell carcinoma occurs in 2% to 3% of cases,
usually affecting older children or adolescents.4
Chest radiography is the initial examination to
diagnose pulmonary involvement. If the chest examination is abnormal, CT is the
imaging examination to assess the extent and stability of disease. The CT
findings of airway involvement are tracheal irregularity, multiple nodules
attached to the tracheal-bronchial walls, and bronchiectasis secondary to
bronchial obstruction and chronic infection. Postprocessing techniques, such as
multiplanar reconstructions (MPR) and volume rendering (VR), as well as virtual
bronchoscopy (VB), are useful to improve visualization and localization of
lesions. In this case, the MPR showed the lesions attached to the tracheal
wall. The VB demonstrate sessile papillomas.
The characteristic CT findings of lung involvement are
multiple solid and cystic nodules, predominantly in the lower lobes.5
As the nodules grow, the blood supply to the center of the nodules is lost and
central necrosis occurs. The cystic nodules may enlarge and form large cavities
with thick or thin walls. Enlargement of a previously described lesion and
mediastinal lymphadenopathy should increase the suspicion of malignancy.6
In addition, parenchymal complications, such as pneumonia, abscess, and
atelectasis, can be seen.
Conclusion
We present the
CT findings of juvenile recurrent respiratory papillomatosis with pulmonary
involvement. CT provides excellent characterization of anatomy and can help
plan bronchoscopy and tumor resection. Serial CT studies are mandatory because
of the possibility of malignant transformation of papillomas. Current CT
scanners provide high levels of anatomic detail with low radiation doses.
- Larson DA, Derkay CS. Epidemiology of recurrent respiratory papillomatosis. APMIS. 2010;118:450-454.
- Dickens P, Srivastava G, Loke SL, Larkin S. Human papillomavirus 6, 11, and 16 in
laryngeal papillomas. J Pathol.
1991;165:243–246.
- Kramer SS, Wehunt WD, Stocker JT, Kashima H. Pulmonary manifestations of juvenile
laryngotracheal papillomatosis. AJR Am J
Roentgenol. 1985;144:687–694.
- Gerein V, Rastorguev E, Gerein J, et al. Incidence,
age at onset and potential reasons of malignant transformation in recurrent
respiratory papillomatosis patients: 20 years experience. Otolaryngol Head Neck Surg. 2005;132:392–394.
- Prince JS, Duhamel DR, Levin DL, et al. Nonneoplastic
lesions of the tracheobronchial wall: Radiologic findings with bronchoscopic
correlation. Radiographics. 2002;22:S215-S230.
- Frauenfelder T, Marincek B, Wildermuth S. Pulmonary spread of recurrent respiratory
papillomatosis with malignant transformation: CT findings and airflow
simulation. Eu J Radiol Ex.
2005;56:11-16.