Abstract
Objective
The objective is to present an uncommon case of squamous cell carcinoma (SCC) arising from extensive recurrent respiratory papillomatosis (RRP) involving the upper and lower airway and temporal bone.
Study Design
This is a case report and a review of the literature.
Methods
We describe a case of a 24-year–old woman with a history of human papillomavirus (HPV) type 11 since childhood originating in the larynx and trachea, then progressing to involve the distal pulmonary alveoli and right middle ear through the eustachian tube. Papillomatous growth was treated with multiple surgeries including laser cytoreduction of laryngotracheal papillomatosis and radical mastoidectomy, followed by a trial of chemotherapy. Despite this aggressive treatment regimen, papillomatous growth progressed with recurrence in the right eustachian tube, middle ear, and mastoid eventually extending to involve the calvaria and scalp.
Results
The patient underwent a composite resection of involved tissues, including the scalp, auricle, and lateral temporal bone, with reconstruction using a latissimus dorsi free flap. Final pathologic analysis revealed an extensive infiltrative well-differentiated SCC arising from the papilloma. A review of the literature on aggressive respiratory papillomatosis suggests that malignant transformation of juvenile-onset RRP occurs exclusively in cases positive for HPV-11.
Conclusions
We report an unusual case of SCC originating from extensive RRP involving the airway, temporal bone, and scalp and describe the medical and surgical management. Although the incidence of juvenile-onset RRP transformation to SCC is very low, the presence of HPV-11 as a risk factor for malignant transformation of RRP is becoming evident.
1
Introduction
Recurrent respiratory papillomatosis (RRP) is the most common benign neoplasm of the larynx, and its association with human papillomavirus (HPV) types 6 and 11 are now well established . The clinical course of RRP varies widely, ranging from spontaneous resolution to aggressive progression of the papillomas, which can lead to dangerous airway compromise and, in less than 1% of occasions, to malignant transformation . Over the past 2 decades, there have been a number of reports describing the development of squamous cell carcinoma (SCC) from extensive cases of RRP and, more specifically, of juvenile-onset RRP. At least 19 cases of malignant transformation of juvenile-onset RRP in which the viral pathogen was identified are reported in the literature; and interestingly, HPV-11 has been detected in all cases .
We describe a patient with a long history of RRP involving the lungs, trachea, larynx and pharynx, eustachian tube, middle ear, and mastoid who developed a SCC arising from the RRP. Human papillomavirus genotyping revealed that this case of RRP was associated with HPV-11. In this report, we add to the collection of cases linking malignant transformation of juvenile-onset RRP to this specific viral type. In addition, the presentation and management of a unique extension of RRP disease through the eustachian tube and out onto the scalp through a postoperative ear are described.
2
Case report
The patient is 24-year–old Asian woman diagnosed at the age of 2 years with RRP primarily affecting her nasal cavity and nasopharynx. By the age of 10 years, however, she began to develop hoarseness and soon required regular laser ablations of laryngeal papillomas. Having undergone more than 200 procedures without any episodes of dyspnea, shortness of breath, or stridor, she was considered to have a chronic, stable form of RRP. However, at the age of 22 years, she experienced symptoms of airway distress and needed to be taken to the operating room for emergent laser treatment. Viral testing done at the time demonstrated HPV-11–associated RRP. Additional workup revealed extensive pulmonary involvement; and accordingly, the patient was started on intralesional cidofovir and subcutaneous interferon alfa-2b therapy. With subsequent further progression of disease, she was initiated on intravenous cidofovir, which reduced the average interval between surgeries but failed to bring about disease regression. Papillomatous extension into the eustachian tube and trachea furthermore required regular medical therapy for recurrent acute otitis media on the right side and thoracic surgical involvement for tracheal disease debulking.
The patient later presented with a House-Brackmann grade II right-sided facial weakness, and computed tomographic (CT) imaging revealed complete opacification of the right mastoid with a soft tissue mass filling the medial one half of the external auditory canal (EAC). There were significant bony erosion and destruction present within the central mastoid air cells, along the tegmen, along the posterior wall of the EAC, and within the middle ear. Expansion of the bony canal of the right eustachian tube was also noted. Biopsies taken from the lesions within the EAC were consistent with papilloma and were without evidence of malignancy. A magnetic resonance imaging (MRI) scan to examine for evidence of intracranial involvement was requested; however, the patient was unable to tolerate the scan. In an attempt to eradicate the otologic disease, she underwent a right radical mastoidectomy with removal of papilloma and tympanomastoid obliteration with an abdominal fat graft. Intraoperatively, a small encephalocele in the tegmental defect was noted and removed; and the dural defect was repaired with temporalis fascia. Postoperatively, the patient developed mild serous drainage from the wound and was started on oral antibiotic therapy. Subsequently, however, the patient was lost to follow-up for 6 months.
She later re-presented with persistent serous drainage from the wound and a 4-cm postauricular exophytic mass originating from the incision line and extending from the mastoid tip to several centimeters above the temporal line. The CT scans revealed a large lesion centered in the area of the temporal bone with extension over the parietal bone, into the petrous apex with bony destruction approaching the cavernous carotid artery, inferior extension into the jugular foramen and into the neck, and involvement of the dura of the middle and posterior fossae ( Fig. 1 A-D ). Despite initiation of systemic chemotherapy, including carboplatin, paclitaxel, and cetuximab, the mass continued to progress ( Fig. 2 A ); and the patient underwent subtotal resection, including a wide local excision of the right scalp, total auriculectomy, lateral temporal bone resection, and reconstruction with a free latissimus dorsi muscle flap with split-thickness skin graft coverage ( Fig. 2 B-D).
At the conclusion of the case, a wound vacuum was applied at 125 mm Hg to secure the skin graft to the underlying muscle flap ( Fig. 3 A ). The postoperative course was unremarkable, and the patient was discharged home on postoperative day 7. At initial follow-up, the flap appeared healthy, viable, and to have 100% skin graft take ( Fig. 3 B).
