How is microscopy of lichen planus?

➢ a prototypical interface dermatitis : so called because the inflammation and damage are concentrated at the interface of the squamous epithelium and papillary dermis. ➢ a dense, continuous infiltrate of lymphocytes along the dermoepidermal junction. ➢ The lymphocytes are intimately associated with basal keratinocytes, which often atrophy or become necrotic. ➢ Perhaps as a response to damage, the basal cells take on the appearance of the more mature cells of the stratum spinosum. ➢ This pattern of inflammation causes the dermoepidermal interface to assume an angulated, zigzag contour (sawtoothing). ➢ Anucleate, necrotic basal cells are seen in the inflamed papillary dermis and are referred to as colloid bodies or Civatte bodies.