Aacntholytic acanthoma

•Common, solitary keratotic papule or plaque (0.5-1.5 cm) in the elderly

•Predilection for males

•Trunk, arm & neck but may arise elsewhere

•Histology is Darier-like

•If dyskeratosis is marked, the term acantholytic dyskeratotic acanthoma has been applied

Acantholytic dermatosis of the genitocrural region

•Predilection for young or middle-aged females

•0.1-0.5 cm single or multiple papules involving the labia majora +/- erythematous or white plaques

•Sometimes with involvement of perineum, thighs & inguinal region

•In males, the ano-genital regions are affected

•No clinical evidence of Grover, Darier or Hailey-Hailey disease

•Exceptional cases thought to represent genetic mosaicism with ATP2A2 & ATP2C1 somatic mutations

•Histology resembles Darier, Hailey Hailey disease or warty dyskeratoma

Warty dyskeratoma

•Umbilicated solitary nodule on sun-damaged skin of the head & neck but may arise elsewhere

•Rarely multiple lesions are present

•Follicular continuity often evident

•Cup-shaped, cystic invagination containing keratinous debris showing conspicuous corps ronds & grains of Darier 

•The deeper reaches show acantholysis and prominent suprabasal villi

Focal acantholytic dyskeratosis

This term is used for localized acantholysis with dyskeratosis occuring as an incidental finding is a specimen excised for some other lesion. The image belw came from a adjacent univolved skin in an excision specimen