Lichen planus ppt

HISTOPATHOLOGY LICHEN PLANUS,ITS VARIANTS AND SOME DIFFERENTIAL DIAGNOSIS

1. BY :- DR PUSHKAR CHAUDHARY SSSMCRI 2 ND YEAR PG MD PATHOLOGY GUIDED BY : PROF NASEEM NOORUNNISA PROF AND HOD DEPT OF PATHOLOGY SSSMC&RI LICHEN PLANUS

2. OVERVIEW SKIN NORMAL HISTOLOGY MICROSCOPIC TERMINOLOGY LICHEN PLANUS DEFINITION PATHOGENESIS MORPHOLOGY VARIANTS DIFFERENTIAL DIAGNOSIS

3. SKIN NORMAL HISTOLOGY

4. MICROSCOPIC TERMINOLOGY Acanthosis - Diffuse epidermal hyperplasia Hyperkeratosis -Thickening  of the stratum  corneum , often associated with a qualitative abnormality of the keratin Parakeratosis - Keratinization  with retained nuclei in the stratum  corneum Orthokeratosis  is Hyperkeratosis without parakeratosis

5. Hypergranulosis - Hyperplasia of the stratum  granulosum , often due to intense rubbing Vacuolization- Formation of vacuoles within or adjacent to cells; often refers to basal cell-basement  membrane zone (BMZ) area . Spongiosis - Intercellular edema of the epidermis

6. DEFINITION Lichen planus is a subacute or chronic dermatosis that may involve skin, mucous membranes, hair follicles, and nails .

7. PATHOGENESIS The pathogenesis of lichen planus is not known. It is plausible that expression of altered antigens in basal epidermal cells elicit a cell-mediated cytotoxic (CD8+) T cell response . T-lymphocyte infltrates and Macrophages are characteristic features of this disorder.

8. MORPHOLOGY Cutaneous   lesions  consist  of  itchy,  violaceous ,  flat -topped papules that may coalesce focally to form plaques . These papules are often highlighted by white dots or lines called  Wickham striae , which are created by areas of hypergranulosis . 

9. MORPHOLOGY Lesions are usually multiple and  symmetrically  distributed ,  particularly  on  the  extremities  and often about the wrists and elbows.  The   glans  penis is another common site of involvement .

10. Histopathology LAYER FINDINGS ST RATUM CORNEUM Hyperkeratosis w/o parakeratosis Oral LP  parakeratosis rather than hyperkeratosis STRATUM GRANULOSUM Focal wedge shaped hypergranulosis STRATUM SPINOSUM Irregular acanthosis with saw-toothed rete ridges Intercellular edema STRATUM BASALE Vacuolar alteration ) Liquefaction degeneration ( of the basal cells Colloid (Civatte, hyaline or cytoid) bodies Max Joseph spaces (Clefts between the epidermis & dermis) PAPILLARY DERMIS Lichenoid l ym p hohistiocytic infiltrate  dense, b and- l ike infiltrate (interface dermatitis) Colloid ( Civatte ) bodies Melanin incontinence  Melanophages LPP  lymphohistiocytic infiltrate around hair follicle

11. VARIANTS Hypertr ophic lichen planus A trophic lichen planus Ulcerative (erosive) lichen planus Lichen planus actinicus Lichen planopilaris (LPP )

12. Hypertrophic lichen planus

13. Atrophic lichen planus

14. Ulcerative lichen planus Epidermal ulceration with lichen planus at margins.

15. Lichen planus actinicus Resembles lichen planus but more melanin incontinence; focal parakeratosis

16. Lichen planopilaris

17. DIFFERENTIAL DIAGNOSIS Lichen planus like keratosis Lichen nitidus Lichenoid drug eruptions Lichen striatus Discoid lupus erythmatosus

18. LICHEN PLANUS LIKE KERATOSIS LP+PARAKERATOSIS(MORE COMMON)+EOSINOPHILS AND PLASMA CELLS IN THE INFILTRATE(MORE COMMON)

19. LICHEN NITIDUS

20. BALL IN CLAW APPEARANCE

21. LICHEN STRIATUS

22. DISCOID LUPUS ERYTHMATOSUS