CHILD Syndrome: Analysis of Abnormal Keratinization and Ultrastructure

Abstract

A new patient with CHILD syndrome (congenital hemidysplasia, ichthyosiform erythroderma, and limb defects), the thirtieth in the literature, was observed for over three years. Initially, the right-sided lesion spared the breast area. At 10 months of age the trunk lesion extended to cover the entire area of the right chest. At age 20 months the patient developed linear, bandlike, keratotic, brown-black lesions on her left thigh that subsided within six weeks, leaving a slight hyperpigmentation. This patient was studied by routine histologic methods as well as with markers of keratinization and electron microscopy. In hematoxylin and eosinstained sections, parakeratosis and orthokeratosis alternated. In some parakeratotic areas, large granular cells, and in others, ghost granular cells, were present. The latter showed basophilic cytoplasm, and palestaining or vacuolated nucleus and were seen either above the normal granular layer or without it. Although regional variations existed, basal cell-type keratins as recognized by AE1 continued to be expressed in suprabasal layers. Filaggrin- and involucrin-positive layers were expanded, particularly the latter, down to the lower prickle cell layer. Ultrastructurally, numerous lamellar or membranous structures were found in upper layers of the epidermis, both intracellulary and intercellularly. Normal cementsomes coexisted with these abnormal lamellar structures, and it was thought that the latter represent modified cementsomes because the discharge of those from the cell periphery was often detected.

The group of epidermal nevus syndromes

“…246 On electron microscopic examination, vesicular structures are found to be accumulated within the horny layer. 246,247 By way of exception, a bilateral, almost symmetric involvement may occur. [248][249][250][251] Therefore, it is important to realize that the peculiar pattern of lateralization is not always present and is not a prerequisite for the diagnosis.…”

Response to Happle

“…In the authors' patient, all of the clinical and histopathologic features of the alleged lichen striatus are compatible with CHILD nevus. In particular, waxing and waning of parts of the lesions is a characteristic finding of this disorder (4). This view is supported by the fact that the authors documented in their case a small "preexisting" part of the eruptive contralateral linear skin lesions.…”

Palmoplantar Keratoderma (Voerner) with Composite Keratohyalin Granules: Studies on Keratinization Parameters and Ultrastructures

“…This phenomenon may be related to the early development of a marginal band below the granular layer, as shown in Figures 8 and 9. However, in some other conditions in which the expression of this complex was extended (15,16), the premature formation of the marginal band was not observed.…”

“…Abnormal expression of filaggrin could also be a primary or secondary phenomenon. In abnormal keratinization, the epidermal differentiation complex including involucrin, loricrin, and their cross-linking enzyme, TGK, shows abnormal expression, usually as widening of staining to the lower epidermis (15,16). This phenomenon may be related to the early development of a marginal band below the granular layer, as shown in Figures 8 and 9.…”