| Abstract: | Two cases of irritated seborrheic keratosis ofthe eyelid were studied clinicopathologically. Oneunusually large tumor was confirmed benign electronmicroscopically. Under light microscope, irritatedseborrheic keratosis was diagnosed by the presence ofits "stuck on" configuration, numerous horn cysts,and squamous eddies among the proliferated basaloidand squamoid cells. Ultrastructurally, both thebasaloid cell and squamoid cell showed highdifferentiation and well-formed organelles in thecytoplasm. The nuclear chromatin was even and fine, and the nuclear membrane smooth and regular.Tonofilaments and desmosomes could be found.These ultrastructural findings were consistent with the concept that seborrheic keratosis develops on the basis of local arrest of keratocyte maturation. |
