title: Cutaneous defects of focal dermal hypoplasia: an ectomesodermal dysplasia syndrome.
abstract: The 5 major cutaneous defects of development found in focal dermal hypoplasia, an ectomesodermal dysplasia syndrome, are: aplasia cutis congenita, multiform atrophy-like areas, striate, papillomatous, and lipomatous lesions of skin. Subepidermal lipomatosis, present in some lesions, has been reported to be due to absence of dermis or a striking underdevelopment of connective tissue with replacement by adipose tissue from herniation of subcutaneous fat through multiple areas of hypoplasia. We believe this theory to be a major error in interpretation of the microscopic findings. We have had the unique experience of studying 2 patients periodically for 27-30 years and 2 additional patients for a shorter time. Biopsy specimens were removed at intervals for analysis from the same or similar lesions (43 specimens) from these 4 individuals. Our evidence strongly supports the concept that the cutaneous defects of development involving fat cells represent heterotopic fat i.e. a fat nevus resulting from dysplasia, not hypoplasia followed by herniation of subcutaneous fat.
authors.affiliation: Department of Dermatology, University of Texas Southwest Medical Center, Dallas.
authors.forename: J B
authors.initials: JB
authors.lastname: Howell
authors.forename: R G
authors.initials: RG
authors.lastname: Freeman
mesh_terms: D000273:Adipose Tissue / Q000473:pathology; D000328:Adult; D001284:Atrophy; D002648:Child; D004476:Ectodermal Dysplasia / Q000473:pathology*; D005260:Female; D005489:Focal Dermal Hypoplasia / Q000150:complications / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007223:Infant; D008067:Lipoma / Q000150:complications / Q000473:pathology; D010212:Papilloma / Q000150:complications / Q000473:pathology; D012867:Skin / Q000473:pathology; D012868:Skin Abnormalities; D012878:Skin Neoplasms / Q000150:complications / Q000473:pathology; D013577:Syndrome