Neutral lipid storage disease with ichthyosis. Defective lamellar body contents and intracellular dispersion

Although the link between epidermal lamellar body lipids and stratum corneum barrier function is well established, a role for lamellar body lipids in desquamation remains unproved. We examined skin biopsy material from three family members of a Palestinian kindred with a multisystem disorder of altered lipid metabolism, ichthyosis, and deposition of fat droplets in multiple tissues (Chanarin-Dorfman syndrome, neutral lipid storage disease). Thin-section and freeze-fracture ultrastructural studies revealed a distinctive lamellar body abnormality: multilaminated spherules that distorted and displaced the normal internal disk structure of these organelles. Whereas these spherules remained interspersed with secreted lamellar body contents within the intercellular spaces of the outer epidermis, at the stratum granulosum-stratum corneum interface they apparently dispersed into electron-lucent "slits." These studies therefore provide strong support for the concept that lamellar body-derived lipids influence stratum corneum desquamation and further suggest that abnormalities of neutral lipid-alkane metabolism influence normal epidermal shedding.