ACase of Dermal Infiltration of Langerhans Cells :An Ealy Stage of Cutaneous Langerhans Cell Histiocytosis ?

Abstract

A79-year-old male suffered from itching dermatitis for several months, gradually spreading from the pelvic region to the trunk and central extremities. Six-month treatment with topical steroid ointment prescribed by the previous doctor showed only limited effectiveness. Physical examination disclosed numerous slightly pigmented new and old erythematous plaques over the body. Each eruption was smaller than 3 centimeters in diameter and slightly palpable. Tumorous lesions were absent. Biopsy examination disclosed extensive histiocytoid and mononuclear cell infiltrations in the upper dermis. However, the marked proliferation of these cells was not detected. Immunohistochemical examination demonstrated abundant CD1a ＋ cells infiltration and much amount CD3＋ cells, but CD20＋ cells and CD68＋ cells were only sparsely distributed. Further examination for whole body found no lymph node swelling, abnormality of peripheral blood count, or monoclonal rearrangement of T-cell receptor genes. NB-UVB irradiation therapy was started, and the eruptions diminished in the three subsequent months. A2-year follow-up revealed no recurrence of the skin disturbance. Not only typical cases of Langerhans cell histiocytosis, involving multisystemic and tumor-forming, neoplastic, and clonal proliferation of Langerhans cells occurring in infants and children, but also cases showing skin limited infiltration or proliferation of Langerhans cells are reported. They include self-healing cases of neonate and infant, and adult types that show wide spread eruptions. They are now called cutaneous Langerhans cell histiocytosis. This case is diagnosed as an early stage of cutaneous Langerhans cell histiocytosis. Skin Research, 19 : 169-173, 2020