Frequency and significance of epithelial atypia in laryngeal papillomatosis

Laryngeal papillomatosis is the most common proliferative lesion of the larynx in children. The best evidence to date suggests that a virus, presumably one of the papova virus group, is responsible and that there is a strong relationship between laryngeal papilloma and the condylomata of the mother. The clinical behavior of these lesions is characterized by relentless recurrences and in some cases eventual spread down the tracheobronchial tree to the lung parenchyma. Although classified histologically as benign varying degrees of atypia of the epithelium have been observed together with changes in the cellular composition of the subepithelial layers. Some of the epithelial changes have bordered on carcinoma in situ. The pathologists have been reluctant to make this diagnosis because of the implication of such an interpretation. Parenthetically an identical appearance from a laryngeal biopsy from an adult would unhesitatingly be interpreted as severe dysplasia-carcinoma in situ. It is apparent that the malignant potential of these histological alterations is extremely low as reflected by the rarity of squamous cell carcinoma arising in laryngeal papilloma. Some exceptions have been reported in children who received radiation therapy, and there have been occasional reports of carcinoma of the larynx arising without irradiation. To what extent should the interpretation of atypia influence the management of the patient? What are the criteria for labelling atypia and cellular change in papillomatosis? What exogenous influence exists which may induce this atypia; is it related to a longer course of the disease, tracheostomy or to the site of the lesions? These questions pose a dilemma to the pathologist and surgeon. The surgical-pathological specimens of laryngeal papillomatosis will be correlated with the clinical course of the disease and the presence of exogenous factors. A system of grading atypias will be presented, and criteria for diagnosis will be suggested. Correlation between histological grading and clinical course of the disease will be explained. A literature review reveals that apparently there has been no previously reported study of these factors, and it would seem essential that if patterns of change exist they must be clearly interpreted by the pathologist and promptly brought to the attention of the surgeon.