Malignant transformation in intra oral papillary lesions diagnosed in the department of pathology, faculty of medicine, Makerere University, Kampala

Abstract

Oral papillary lesions account for two and a half percent of benign neoplastic lesions of the oral mucosa and occur at any site within the oral mucosa. Some oral papillary lesions have been associated with HPV infection. An increased incidence of oral papillary lesions in individuals undergoing highly active anti retroviral therapy has been documented. OBJECTIVES: The aim of this study was to document the different histological variants of intra oral papillary lesions diagnosed in the department of pathology, faculty of medicine, makerere university and determine whether they show features of malignant transformation, which include epithelial dysplasma, cellular and nuclear atypia, presence of abnormal mitoses and altered nuclear-cytoplasmic as well as describe the pattern of cytokeratin 19 expression in the epithelial lining of intra- oral papillary lesions. METHODS: This was a laboratory based descriptive cross sectional study on formalin fixed paraffin wax embedded tissue samples of intra oral papillary lesions from the Department of pathology., Faculty of medicine, makerere university. Routine haematoxylin and eosin staining of sections was done in addition to immunohisto-chemical staining using monoclonal antibodies for cytokeratin 19. RESULTS: The histological variants of intra oral papillary lesions seen were oral aquamous papilloma comprising 29 (46.8%) specimens, polyps comprising 15 (24.6%) specimens and one verruca vulgaris. The features of malignant transformation found in this study were epithelial dysplasia in 18(38.3%) specimens followed by nuclear pleomorphism in 9 (19.1%) specimens, increased cyplasmic ratio in 9 (19.1%) specimens, cellular pleomorphism in 7 (14.9%) speciens, abnormal mitoses in 6 (12.8%) specimens and keratin pearls in 5 (10.6%) specimens. Cytokeratin 19 expression within the prickle cell layer was found to be associated with epithelial dysplasia. CONCLUSION: Oral squamous papillomas are the commonest intra-oral papillary lesion showing an equal sex distribution and predilection for the tongue. None of the lesions seen had all the histological features of malignant transformation. Epithelial dysplasia and cytokeratin 19 expression within the prickle cell layer were seen more frequently in specimens from females. Intra oral papillary lesions in women should be routinely biopsied and pathologists should pay special attention while looking for features of dysplasia in such specimens.