Aplasia cutis congenita of the scalp: Histopathologic features and clinicopathologic correlation in a case series

Abstract

Background: Aplasia cutis congenita (ACC) is a rare and heterogeneous disorder characterized by congenital absence of skin. The scalp is the most commonly affected site and lesions may overlie deeper ectodermal abnormalities. The exact etiology is still unknown, and histopathologic features are poorly defined.Methods: A series of 10 cases from nine patients was analyzed to characterize the clinicopathologic spectrum and age-related changes of ACC of the scalp. Hematoxylin and eosin, S100, Elastica van Gieson, and Weigert elastic stains were performed, and clinical information was retrieved from archived medical files.Results: Patient ages ranged from 1 day to 39 years (median 57 months). All cases resembled deep-reaching scars with almost complete loss of all adnexal structures.Isolated residual hair follicles were present in 8/10 and sweat glands and ducts in 2/10 cases. The subcutis was thinned or absent. Elastic fibers were always more fragmented than in normal tissue, and the thickness and density increased over time.There was no gain of adnexal structures with increasing age. Conclusions: ACC represents a congenital scarring alopecia with permanent loss of skin appendages. Histopathologic changes resemble a deep-reaching scar with fragmented elastic fibers and differentiate ACC from all other forms of non-traumatic congenital alopecias. K E Y W O R D S aplasia cutis congenita, cicatricial alopecia, congenital scalp defect, ectodermal dysplasia, elastic fibers

Aplasia cutis congenita in monozygotic twins

“…It can occur on any part of the body, but most commonly on the scalp. ACC is an uncommon disorder with a birth rate of around 1 to 3 in 10 000 live births 3 . Post wound healing, these scalp defects can easily be confused with other diseases of hair loss such as alopecia areata, scarring alopecia, trichotilomania, traction alopecia and syphilitic alopecia.…”

Embryological Prerequisites for Human Cranial Developmental Deffects

“…Частота становить 1 на 3000 живонароджених, а система класифікації підтипів аплазії верхньої частини шкіри голови була запропонована Frieden. При швидкому закритті рани та здоровій твердій мозковій оболонці відбудеться ріст черепної кістки, і ризик крововиливу або менінгіту значно зменшується [45].…”