[Epithelio-lymphohistiocytic tumor. Apropos of 3 cases]

We report three cases of epithelio-lympho-histiocytic tumour with very original histological features. The patients were young adults presenting with a nodular lesion on the face which had been present for several years. No recurrence was observed after surgical excision. Histologically, the dermal lesion consisted of epithelial pouches edged with a few layers of basal-like cells and filled with lymphocytes and large clear cells. Relations were found between these lobules and hair follicles, and rudiments of piliary differentiation were noted. The stroma was dense and infiltrated by small lymphocytes and large clear cells. An immunohistochemical study showed marking of the large clear cells by the S 100 protein, which suggested that they were Langerhans cells. The lymphocytes were recognized by the common panleucocyte antibody. The KL 1 antibody marked a few isolated cells within the lobules, but not the basal-like cells. These cases seemed to be similar to the 7 cases reported in the literature by Santa-Cruz and Barr who used the term lymphoepithelial tumour of the skin. We felt justified in putting the stress on the histiocytic component of this tumour and calling it epithelio-lympho-histiocytic tumour. We agree with these authors that this is a tumour of the appendages of the skin and in particular the hair.