Abstract
An 80-year-old man noticed a verrucous tumor on his head. The tumor consisted of a black nodule and a light-red nodule. Histopathologically the former was trichilemmoma (Tr), while the latter was proliferating trichilemmal tumor (PTT). It was uncertain whether or not the PTT was malignant, because the tumor cells were composed of atypical cells and mitotic cells, and the atypical cells were stained positive with anti-proliferating cell nuclear antigen (PCNA) antibody. It is well known that sugarchains of glycoproteins and glycolipids on cell membrane show structural alterations during malignant transformation. Therefore, we immunohistochemically investigated Tr, PTT and normal follicles regarding their lectin-binding characteristics. As a result, apparent differences in the staining properties were found between PTT and the normal follicles, but not between PTT and Tr.
