A 62-year-old male presented with and inflammatory plaque on his right neck. Clinical examination demonstrated a large, hyperkeratotic, verrucous plaque with evidene of surrounding inflammation. A lesional skin biopsy was taken for hematoxylin and eosin (H & E) analysis, and immunohistochemistry (IHC) studies were also performed. Skin biopsies for hematoxylin and eosin examination, as well as for immunohistochemistry (IHC) analysis were performed as previously described[]. Examination of the H & E tissue sections demonstrated epidermal hyperplasia with minimal cytologic atypia; pseudo-horn cyst formation was present. The base of the lesion displayed a relatively flat morphology. An infiltrate of lymphocytes and histiocytes was also present within the papillary dermis, immediately subjacent to the lesion. Next, IHC stains were reviewed against linker for activated T cells (LAT), cyclooxygenase-2 (COX-2), CD1a and CD68. These special stains displayed strong expression of these molecules within the previously described dermal inflammatory infiltrate. In addition, myeloid/histiocyte antigen was strongly, focally expressed by lesional keratinocytes ().