Subepidermal calcified nodule in children: a clinicopathologic study of 21 cases.

Twenty-one cases of subepidermal calcific nodule are presented. These lesions occur twice as commonly in males compared to females, with the head (particularly the ear), and neck as favored locations. No case was identified correctly clinically and only 1 case had a history of trauma, which appeared unrelated to the lesion. Histologically, there was a variety of appearances, with two-thirds of specimens exhibiting a warty architecture. Younger lesions were composed of large, amorphous, calcific dermal deposits and were frequently associated with epidermal ulceration. The older lesions were not ulcerated and the calcium deposits were in small spherules. There was no evidence of pilomatrixoma or pre-existing nevus. It is hypothesized that subepidermal calcified nodule represents dystrophic calcification secondary to dermal injury-several in our series showed the architectural changes of verruca vulgaris.