Survivin expression in canine hair follicle tumours

Introduction. Despite the vast body of knowledge on survivin expression in skin tumours, no data are available concerning survivin expression in hair follicle neoplasms. The aims of this study was to evaluate survivin expression pattern in canine hair follicle tumours. Materials and Methods: Survivin expression was investigated by immunohistochemistry in 4 normal canine skin samples, 30 hair follicle tumours (6 pilomatricomas, 8 infundibular keratinizing acanthomas-IKA, 6 trichoepiteliomas, 10 trichoblastomas) and 2 basal cell carcinomas (BCC). A semi-quantitative method was used to analyse results. Mitotic index was morphologically evaluated. Results: Nuclear immunolabelling with positive mitosis have been observed among basal cells of normal epidermis, outer root sheath, hyperplastic epidermis overlying the tumours and neoplastic cords of IKA cases. Scattered positive matrical cells were present in the bulb of normal hair follicles. The highest number of positive cells (>50%) were present in pilomatricomas and trichoepitheliomas, among cells with matrical differentiation, and in some cases of trichoblastoma. Few or absent positive cells were observed in BCCs. Conclusion: In accordance with previous study on human hair follicle, our results suggested that survivin could represent a key molecule in the maintenance of cellular subpopulations of canine hair follicle, as well as of tumours deriving from these cells: trichoepithelioma, trichoblastoma and pilomatrixoma. [...]