Laryngeal papillomatosis

A 23-year-old woman with a known history of laryngeal and tracheal papillomatosis sought evaluation for increasing shortness of breath and persistent cough. Computed tomography (CT) of the chest revealed the presence of a soft-tissue mass in the trachea and significant compromise of the tracheal lumen; almost 80% of the lumen surface was occluded (figure 1). CT also identified several other nodular lesions along the remainder of the inner tracheal wall and nodular and cavitated lung parenchymal lesions bilaterally.

[FIGURE 1 OMITTED]

Magnetic resonance imaging (MRI) of the neck and chest demonstrated endoluminal papillomas of the tracheal wall; there was no evidence of invasion into the adjacent soft tissues of the mediastinum (figure 2). The dominant intraluminal lesion in the distal trachea exhibited an intermediate signal intensity on T1-weighted imaging and a higher signal intensity on T2-weighted imaging. These findings were worrisome because they suggested the possibility of malignant transformation. Fortunately, an endoscopic biopsy ruled out malignancy.

[FIGURE 2 OMITTED]

Recurrent respiratory papillomatosis (juvenile laryngeal papillomatosis) is a rare disease caused by herpes simplex, one of the DNA viruses, (1,2) but it is the most common benign neoplasm of the larynx and the most common cause of hoarseness in children. (3) It is characterized by endoluminal growth lesions in the respiratory tract. Recurrent respiratory papillomatosis usually runs a benign course and goes into remission during puberty. However, some patients experience a prolonged course and develop numerous associated complications, including airway obstruction, distal spread into the tracheobronchial tree, and involvement of pulmonary parenchyma leading to postobstructive atelectasis and recurrent pneumonias.

Macroscopically, a papilloma appears as an exophytic, cauliflower-like mass. Histologically, it exhibits finger-like projections of stratified squamous epithelium with a fibrovaseular core. Basal cell hyperplasia and large vacuolated epithelial cells with a clear cytoplasm are typical. (1) Although histologically benign, its potential to obstruct the airway is serious and potentially life-threatening. The incidence of spontaneous malignant degeneration in both laryngotracheal and bronchoalveolar areas is approximately 2 to 3%; spontaneous degeneration occurs more often in those patients who have prolonged and recurrent disease. (4)

The larynx is affected in almost all cases, and most cases involve the glottis, usually affecting both true vocal folds, primarily along their superior surfaces. The trachea and/or proximal bronchi are affected in 5% of cases, and lung parenchyma dissemination occurs in 1% of cases. (1,2)

CT or MRI can be performed for the evaluation of this entity. One major advantage that MRI has over CT is that MRI can show different structures in multiple planes and with a higher degree of soft-tissue contrast resolution. MRI should be performed before and after intravenous contrast administration. On nonenhanced studies, the intraluminal lesions are of intermediate signal intensity and are easily distinguished from adjacent fat. However, the contrast-enhanced lesions on T1-weighted sequences are often difficult to differentiate from adjacent fat and from marrow-containing laryngeal cartilages, which are usually present in elderly patients. This limitation can be overcome by using fat-suppression techniques. (5)

References

(1.) Kramer SS, Wehunt WD, Stocker JT, Kashima H. Pulmonary manifestation of juvenile laryngotracheal papillomatosis. AJR Am J Roentgenol 1985:144:687-94.

(2.) Lui D, Kumar A, Aggarwal S, Soto J, CT findings of malignant change in recurrent respiratory papillomatosis. J Comput Assist Tomogr 1995;19:804-7.

(3.) Patel N, Rowe M, Tunkel D. Treatment of recurrent papillomatosis in children with the microdebrider. Ann Otol Rhinol Laryngol 2003;112:7-10.

(4.) Pransky S, Kang R. Tumors of the larynx, trachea, and bronchi. In: Bluestone CD, Stool SE, Kenna MA, eds. Pediatric Otolaryngology. 3rd ed., vol. 2. Philadelphia: W.B. Saunders, 1996: 1402 14.

(5.) Stark DD, Bradley WG, Jr., eds. Magnetic Resonance Imaging. 3rd ed., vol. 3. St. Louis: Mosby, 1999:1790.

From the Department of Radiology, Louisiana State University Health Sciences Center, New Orleans.

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