B, Higher magnification reveals features of epidermolytic hyperkeratosis: cytoplasmic vacuolation, coarse keratohyalin
granules, and perinuclear eosinophilic inclusions in the spinous and granular layers (hematoxylin-eosin, original magnifications X40 [A] and X400 [B]).
In the interfollicular regions of tail skin specimen removed from fatty acid mixture-treated mice, granular cells with prominent nucleus and cytoplasm with the typical keratohyalin
granules were found in the epidermal stratum (Fig.
Profilaggrin, which is present in the keratohyalin
granules of human buccal mucosa cells, is proteolytically cleaved into several filaggrin subunits during cell differentiation.
The granular layer was thickened and showed coarse keratohyalin
granules with marked vacuolization of the granular and upper spinous layers.
On the other hand, a keratohyalin
layer and dry flaky keratin, as would be seen in an epidermoid cyst, are also absent.
Showing perinuclear fluorescence, APF is probably an antibody of the 7S gammaglobulin type against keratohyalin
granules in buccal mucosa cells and is high in RA patients compared to the healthy people .
Biopsy was consistent with marked epidermal acanthosis and hyperkeratosis inter and intracellular spaces as a result of suprabasal cytolysis and multiple perinuclear vacuoles and large clumped keratohyalin
granules in the spinous and granular layers (Figure 4).
Electron microscopic findings include lipid-like vacuoles in the corneocytes and granulocytes reduction in tonofilaments and irregular keratohyalin