Incidental acantholysis.

The incidental finding of microscopic foci of acantholytic dyskeratosis, reproducing the histological pattern of Darier's disease, has been the subject of a number of papers in the last few years. In contrast, the incidental finding of other types of acantholysis has not been mentioned in the literature. In the last 5 years, we have noticed such a microscopic finding in 14 biopsy specimens (0.15% of our cutaneous specimens). they were from 13 patients (7 men and 6 women); their ages ranged from 37 to 79 years (mean, 63). Three lesions were located on the head, 7 on the trunk, and 4 on the limbs. The histological diagnoses were basal cell carcinoma (6 cases), keratoacanthoma (2 cases), psoriasis (2 cases), elastolytic granuloma, acral arteriovenous angioma, tinea corporis, and leukocytoclastic vasculitis (1 case each). The histological patterns of the acantholytic foci simulated pemphigus vulgaris (9 cases), superficial pemphigus (1 case), Hailey-Hailey disease (3 cases), and unclassifiable acantholysis (1 case). None of the patients had familial or personal history of acantholytic disorders. We propose a classification of the primary acantholytic disorders based on both their acantholytic pattern and their clinical extent.