Acantholytic Dyskeratotic Acanthoma of the Nail Revealed by a Longitudinal Erythronychia.

Introduction: Focal acantholytic dyskeratosis is a distinctive histological pattern first described by Ackerman in 1972, consisting of focal suprabasal clefts in the epidermis and dyskeratotic cells at all levels of the epidermis with hyperkeratosis and parakeratosis. The first case of subungual acantholytic dyskeratosis acanthoma (ADA) was reported in 1990. This subungual variant is a very rare entity.

Dermoscopy of Lichen Planus Pigmentosus and Histopathological Correlation: A Case Series.

Introduction: Lichen planus pigmentosus (LPP) is an acquired pigmentary disorder affecting the dark-skinned population. There is a wide range of differentials, with substantial clinicopathological overlap. Dermoscopy may contribute to the better characterization of this dermatosis.

New experimental methodology for determining the second crossover energy in insulators under stationary e-irradiation in a SEM.

A new experimental methodology is proposed which uses the electrostatic influence method (EIM) in scanning electron microscope (SEM) in order to estimate the second crossover energy E for uncharged insulators. This experimental methodology based on simultaneous time measurement of the displacement and leakage currents, is approached to the short pulse irradiation technique but under stationary e-irradiation and allows determining the intrinsic secondary electron emission yield, σ (σ is the value of the total secondary electron yield just at the beginning of the irradiation before significant charge accumulation or before the formation of a surface potential). The obtained value of E for soda-lime glass is confirmed by two additional experiments based on secondary electron imaging.