BACKGROUND: The exact origin and classification of warty dyskeratoma in epithelial tumours are still debated. The purpose of this
study was to examine the relationship between this tumour and the pilosebaceous follicles.
METHODS: This was a retrospective, anatomoclinical
study. Expression of cytokeratins 1, 5, 10, 17 and 19 was studied in ten of the samples using Immunohistochemistry techniques.
RESULTS: We studied 43 cases of warty dyskeratoma in 42 patients of mean age 61 years. Lesions were described mainly as papular nodules (70%), in most cases keratotic (58%), with frequent central umbilication (30%), and commonly located in the cervicocephalic region (65%). Histological examination frequently revealed a cupuliform aspect (77%), with numerous contiguous invaginated foci in 43% of cases. Less frequently, the lesions were superficial (12%) or nodular cystic (12%). In 72% of cases, at least one instance of follicular differentiation was seen. CK1 and CK10 were expressed in the suprabasal levels of the warty dyskeratoma while CK5 and CK17 were seen in the basal layers. CK19 was not expressed.
CONCLUSIONS: Based on the histological and immunohistochemical findings, we proposed the hypothesis of benign epithelial tumour of follicular type, beginning in the pilar infundibulum.