Squamous Cell Malignancy Coexisting with Squamous Papilloma in the Larynx: Is This an Entity?

Background: Recurrent respiratory papillomatosis (RRP) is the most common benign mesenchymal neoplasm of the larynx caused by the human papillomavirus (HPV). This condition has a childhood-onset and adult-onset type, which historically has an inclination toward malignant transformation. Case description: A detailed case discussion of two patients with two clinically distinct and dissimilar lesions on two different subsites of the larynx. Both patients were clinically diagnosed to have laryngeal papilloma, with a second malignant lesion. In case 1, the final histopathology of the malignant lesion was found to have papillomatous fronds with evidence of severe dysplasia. In case 2, histopathology of the malignant lesion revealed invasive squamous cell carcinoma with features of papilloma. Both patients revealed "no type" in viral typing. Conclusion: Malignant transformation in adult laryngeal papilloma may occur as a relatively acute phenomenon that may present at the first surgical intervention. It is often associated with the "no type" HPV entity. The presence of squamous papilloma and carcinoma of the larynx, even at two different subsites, should be histologically confirmed and considered a malignant transformation of the laryngeal papilloma. [ABSTRACT FROM AUTHOR]