A 50-year-old man presents with violaceous polygonal flat-topped papules on the wrists. Biopsy shows irregular acanthosis with saw-tooth rete ridges, hypergranulosis, compact orthokeratosis, and band-like lymphohistiocytic infiltrate hugging the DEJ with obscuring the junction. The liquefaction degeneration of basal cells leads to which specific pathological finding?
- A Munro's microabscesses
- B Melanin granules in the mid-epidermis
- C Langerhans cell microabscesses
- D Colloid (Civatte) bodies — eosinophilic degenerate keratinocytes ✓
Explanation
Lichen planus histopathology shows the hallmark lichenoid tissue reaction: saw-tooth rete ridges, wedge-shaped hypergranulosis, band-like subepidermal lymphocytic infiltrate, and basal cell liquefactive (hydropic) degeneration. This basal cell death produces eosinophilic apoptotic keratinocytes called colloid bodies (Civatte bodies or cytoid bodies), which may also be seen in the papillary dermis as they are shed downward. They can stain with TUNEL (apoptosis marker) and contain IgM. Munro's microabscesses (neutrophils in the stratum corneum) are characteristic of psoriasis. Pautrier microabscesses (Langerhans/lymphoid cells in epidermis) are seen in mycosis fungoides.
Reference: Neena Khanna Illustrated Synopsis of Dermatology & STD, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.