<\/span><\/h2>\nAcantolysis is the separation of keratinocytes<\/span> within epidermis<\/span> due to loss of accession<\/span> between keratinocytes. Acantholysis occurs due to failure of the integrity of the intercellular \/intraepidermal<\/span> Cell junctions. This leads to separation of the epithelial<\/span> cells with swelling of the epithelial cells ("balloon degeneration"). In pemphigus foliaceus, there is keratinocyte acantholysis just below the granular layer<\/span> of the epidermis. In comparison, in pemphigus vulgaris there is separation in the basal<\/span> cap<\/span> leading to a "gravestone pattern" of keratinocytes where there is retention of some but not all keratinocytes in the basement membrane. <\/p>\n\n
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<\/span>\nAcantolytic<\/span> dyskeratosis<\/span>
\n<\/span><\/h2>\nAcantolytic dyskeratosis is the reaction pattern characterized by suprabasal cleft<\/span> and acantholysis and dyskeratotic<\/span> Keratinocytes Acantolytic dyskeratosis can be seen in a variety of conditions, but generally Darier's disease, Hailey-Hailey disease, and Grover's disease. The characteristic dyskeratotic cells of acantholytic dyskeratosis are body rounds and body grains. The bodies of the bodies are round dyskeratotic cells with dense basophilic<\/span> (blue) cytoplasm<\/span> (usually acidophilic, pink) with a light area around the core<\/span> (or peri-nuclear<\/span> halo), which is usually located near the basal layer. The grains of the body are small cells, with elongated nuclei<\/span> and it is found in the upper layers of the epidermis.<\/p>\n<\/span>Acanthosis<\/span><\/span><\/h2>\nAcanthosis is a thickening of the epidermis and elongation of the challenge<\/span> ridges due to thickening of the spiny layer +\/- enlargement of rete pegs<\/span>. Typical examples include chronic<\/span> eczematous<\/span> reactions<\/p>\n<\/span>\nAnagen<\/span> <\/span><\/h2>\nAnagen is the growth phase of the hair<\/span> follicle<\/span>. <\/p>\n\n
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<\/span>\nApoptosis<\/span> <\/span><\/h2>\nApoptosis is the normal regulated physiological<\/span> The process by which a cell undergoes a process of death \/ self-destruction in the presence of a suitable signal from the cell's command center, the nucleus. In the epidermis apoptotic<\/span> keratinocytes are usually solitary, scarce and located in the basal layer. They typically have a dark, condensed core chromatin<\/span> (pyknosis<\/span>), chromatin marginalization below the nuclear membrane, followed by nucleus fragmentation (karyorrhexis). Apoptotic cells are smaller than healthy keratinocytes, usually single cells in the basal cells in the epidermal<\/span> layer, sometimes some scattered in the upper layers of the epidermis. <\/p>\n\n- Apoptosis of the keratinocytes of the basal layer results in "bodies of Civatte" (in lichen planus and other lichenoid<\/span> type reactions) or "sunburn cells" (in acute<\/span> Sun tanning).<\/li>\n
- Civatte body is synonymous with "cytoid body", "colloidal body" or "curb<\/span> bodies "and refers to a eosinophilic<\/span> remnant of a keratinocytes<\/span> within the basal or upper papillary layer dermis<\/span>. 'Hyaline<\/span> the bodies are equivalent but occur in connective tissue<\/span>.<\/li>\n
- In some drug reactions, apoptotic keratinocytes can be seen in the basal layer or dispersed in the lower layers of the epidermis.<\/li>\n
- In graft versus host<\/span> disease, apoptotic keratinocytes are seen in association with one or two adjacent<\/span> lymphocytes<\/span> in the basal layer and are called 'satellite cell necrosis<\/span>'.<\/li>\n<\/ul>\n
<\/span>\nAtrophy<\/span> <\/span><\/h2>\nAtrophy refers to a reduction in the size of an organ or part of an organ. In the skin, it can be a reduction in the thickness of the various layers of the skin, for example, epidermal atrophy, dermal<\/span> atrophy, atrophy of panniculus<\/span>.<\/p>\n\n- Epidermal atrophy is characterized by reduction in the number of epidermal cells leading to reduced thickness of the epidermis. Epidermal atrophy can occur after inflammation<\/span> dermal skin (for example lichen sclerosus) or may occur after some skin treatments (for example after long-term use of