Background: Focal acantholytic dyskeratosis is a distinctive histologic pattern characterized by (1) suprabasilar clefts around preserved papillae, (2) acantholytic and dyskeratotic cells at all levels of the epidermis, and (3) hyperkeratosis and parakeratosis. These histologic changes have been observed as an incidental finding in a variety of skin lesions.
Objective: Our purpose was to identify the lesions associated with incidental focal acantholytic dyskeratosis.
Methods: Eight specimens containing incidental focal acantholytic dyskeratosis were retrospectively evaluated, and the published literature describing lesions with incidental focal acantholytic dyskeratosis was reviewed.
Results: The ages of the eight patients ranged from 29 to 53 years. Incidental focal acantholytic dyskeratosis was seen in nevi with architectural disorder (four lesions), scars (two lesions), a ruptured follicle (one lesion), and a seborrheic keratosis (one lesion). Incidental focal acantholytic dyskeratosis was either present in the "clinically normal-appearing" skin adjacent to the lesion (five lesions) or within the lesion (three lesions). Twenty-one additional cases of incidental focal acantholytic dyskeratosis have previously been reported.
Conclusion: Incidental focal acantholytic dyskeratosis has been described in benign and malignant epithelial lesions, fibrohistiocytic lesions, inflammatory lesions, melanocytic lesions, and miscellaneous lesions. This pathologic change was observed either within the actual lesion or in the immediately adjacent epithelium. The cause of this clinically benign, microscopically intriguing condition remains to be determined.