<prompt> Flat topped violaceous papule, thinning of nail.Microscopic finding would be?Basal cell degenerationEpidermal bullaAcantholysisProminent necrotic cells  <response>: As per the clinical features,flat topped papules with thinning of nails are characteristc of lichen planus LICHEN PLANUS:- Histology:-1. Irregular acanthosis of the epidermis.2. Hypergranulosis 3. Compact hyperkeratosis.4. Basal cell damage.5. Colloid bodies6. Pigment incontinence.7. Band like lympho histiocytic infiltrate obscuring the dermoepidermal interface. IADVL TEXTBOOK OF DERMATOLOGY PAGE 1070 