Abstract
An immunohistochemical study with monoclonal anti-keratin antibodies was undertaken in order to compare the keratinizing pattern between seborrheic keratosis (n=12) and irritated seborrheic keratosis (n=8). Lesions of seborrheic keratosis, consisting mainly of basaloid cells, showed anti-keratin reactivity to normal basal cells (PKK 1 and PKK 2), as well as anti-keratin to whole epidermal cells (MA 903), whereas they essentially did not demonstrate any positive reaction with the antibody to the keratinizing supra-basal cells (MA 904). As the lesions were irritated, and the tumor began to consist mainly of squamous cells, anti-keratin immunoreactivity to normal basal cells was no longer detected, whereas a positive reaction to the antibody to keratinizing cells became evident. Such a change was characteristically demonstrated in squamous eddies. The results clearly indicate an alteration in the keratinization pattern after the irritation of seborrheic keratosis.
