A 28-year-old woman has pruritic, polygonal, flat-topped violaceous papules on her flexor wrists and ankles. Examination of the buccal mucosa reveals a lacy white network pattern. Which histopathological feature is MOST characteristic of this condition?
- A Saw-tooth rete ridges with band-like lymphocytic infiltrate hugging the dermo-epidermal junction ✓
- B Munro microabscesses in the stratum corneum
- C Spongiosis with vesicle formation and eosinophil infiltration
- D Granulomatous infiltrate with Touton giant cells in the papillary dermis
Correct answer: A. Saw-tooth rete ridges with band-like lymphocytic infiltrate hugging the dermo-epidermal junction
Explanation
Lichen planus is histologically characterised by hyperkeratosis without parakeratosis, wedge-shaped hypergranulosis, acanthosis with characteristic saw-tooth rete ridges, vacuolar degeneration of the basal layer with colloid (Civatte) bodies, and a dense band-like (lichenoid) lymphocytic infiltrate that closely hugs the dermo-epidermal junction. Munro microabscesses are seen in psoriasis. Spongiosis with eosinophils suggests eczema or contact dermatitis.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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