Cholesteatoma: a morphologic study of stratum corneum lipids.

Two different lipid-retaining fixation techniques permitted electron microscopic visualization of both intra- and extracellular lipids in cholesteatoma epithelium obtained from 25 patients. An increased number of intracellular lipid-containing Odland bodies was demonstrated, with a maximum in the basal layer of the stratum granulosum, while the superior layer contained substantially fewer organelles than are found in normal skin. At the stratum granulosum/stratum corneum interface lipids secreted from Odland bodies were found in sac-like invaginations along the cell membrane but premature exocytosis was also frequently observed. In the intercellular spaces of the stratum corneum, multiple long sheets of lamellar structures interrupted by slits or pores enclosed the keratinized corneocytes. The intercellular spaces seemed narrow and an extracellular barrier was not found until well above the stratum granulosum/stratum corneum interface. A similar distribution of Odland bodies and structure of intercellular lipids can occur in several dermatoses, where the formation and maintenance of the cutaneous permeability barrier are defective.