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 [9].
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 granules.
