Ultrastructure of an Atrophic Type of Senile Keratosis

Abstract

Three cases of an atrophic type of senile keratosis were examined by electron microscopy. All three cases showed similar changes, although some variability from case to case was observed. Lesional epidermis showed remarkable widening of the intercellular spaces with a decrease in the number of desmosomes and detachment of desmosomal connections. Formation of intracytoplasmic vacuoles was also prominent. These changes were localized mainly in the lower part of the epidermis, while the upper epidermis was relatively intact. Discontinuity and multiplication of the epidermal basal lamina were sometimes observed. From these findings, it is concluded that this atrophic type of senile keratosis is characterized by ‘déhiscence cellulaire' with minimal dyskeratosis, although it can properly be regarded as an epidermal precancerous condition.