March 2014, Vol 145, No. 3_MeetingAbstracts Pulmonary Procedures | March 2014
Malignant Transformation of Recurrent Respiratory Papillomatosis: Atypical Presentation as Right Mainstem Bronchus Occlusion Tauseef Siddiqi, MD; Seth Assar, MD; Kevin Lougee, MD; James Knepler, MD University of Arizona, Tucson, AZ
Chest. 2014;145(3_MeetingAbstracts):478A. doi:10.1378/chest.1836553
Abstract SESSION TITLE: Bronchology Case Report Posters SESSION TYPE: Case Report Poster PRESENTED ON: Sunday, March 23, 2014 at 01:15 PM - 02:15 PM INTRODUCTION: Squamous cell carcinoma (SCC) transformation is a known but exceedingly rare consequence of recurrent respiratory papillomatosis (RRP) with approximately one percent of patients afflicted. CASE PRESENTATION: A 22 year old man, with a diagnosis of RRP since childhood, presented with severe sepsis and right sided pneumonia. Radiologic data demonstrated extensive consolidation throughout the right lung and several pedunculated masses within the right mainstem bronchus. He reportedly underwent bronchoscopic biopsy of right mainstem bronchus papillomatous lesion two weeks prior to this presentation. Histopathology results were reported as an invasive SCC. Bronchoscopy after clinical stabilization showed fungating and exophytic mass originating in RUL and extending into right mainstem bronchus causing complete obstruction that was successfully removed. Histopathology results showed squamous papilloma with mild dysplasia. A PET/CT scan after discharge revealed diffuse patchy opacities in the right lung with increased metabolic activity without evidence of distant metastatic disease. He subsequently underwent right thoracotomy and pneumonectomy along with mediastinoscopy with sampling of mediastinal lymph nodes. Surgical pathology report showed invasive well-differentiated SCC arising from squamous papilloma. Surgical margins of right mainstem bronchus and trachea
showed invasive SCC, although all lymph node samples were free of cancer. He is currently under care of thoracic and radiation oncologist. DISCUSSION: RRP is exclusively an acquired disease, and is characterized by recurrent benign papillomas involving upper airways. Direct mucosal colonization by human papilloma virus (HPV) occurs by vertical transmission during vaginal birth. HPV-6 and HPV-11 subtypes are responsible for the majority of cases of RRP. Dyspnea and stridor are often presenting complaints. Surgical debridement with the aim of preservation of laryngeal function is the mainstay of therapy in children and they nearly always left with dysphonia. Malignant transformation into SCC occurs in 2-3%, usually within 10 years of the diagnosis of pulmonary RRP. HPV-11, 16 and 18 subtypes, and concurrent smoking are associated with malignant transformation. Male to female ratio is 2:1 for malignant transformation, for reasons unknown. These patients present with obstructive radiographic abnormalities including recurrent pneumonia, lung abscess, atelectasis or bronchiectasis. Diagnosis is usually at an advanced stage, and majorities are reported as moderate to well-differentiated histologic grade. Therefore, surgical excision has been rarely offered. CONCLUSIONS: Radiographic surveillance for pulmonary involvement is appropriate in patients with severe long-standing RRP. Reference #1: Venkatesan NN, Pine HS, Underbrink MP. Recurrent respiratory papillomatosis. Otolaryngol Clin North Am. 2012 Jun;45(3):671-94. Reference #2: Frauenfelder T, Marincek B, Wildermuth S. Pulmonary spread of recurrent respiratory papillomatosis with malignant transformation: CT-findings and airflow simulation. Eur J Radiol Extra 2005;56:11-6. Reference #3: Cook JR, Hill DA, Humphrey PA, Pfeifer JD, El-Mofty SK. Squamous cell carcinoma arising in recurrent respiratory papillomatosis with pulmonary involvement: emerging common pattern of clinical features and human papillomavirus serotype association. Mod Pathol. 2000 Aug;13(8):914-8. DISCLOSURE: The following authors have nothing to disclose: Tauseef Siddiqi, Seth Assar, Kevin Lougee, James Knepler No Product/Research Disclosure Information