Langerhans' cell histiocytosis (LCH) (histiocytosis X).
HISTOPATHOLOGIC FINDINGS AND CLINICAL COURSE
The histopathologic examination (Figure 3) revealed a dense dermal infiltrate of histiocytes with some eosinophils, lymphoid cells, and plasma cells. Focal epidermal invasion was noted. Immunohistochemical studies with monoclonal antibodies, performed on paraffin- and cryostatembedded tissue sections, showed S100 protein and CD1 and HLA-DR labeling. Ultrastructurally, the Birbeck or Langerhans granules were present in a significant number of histiocytes.Thorough evaluation for visceral involvement was negative. Besides diabetes insipidus and mellitus no other endocrinopathy was found. The patient received vinblastine sulfate (3.7 mg/m2) intravenously on a weekly basis, with progressive augmentation of the dose. After 2 months of treatment, a satisfactory, though still incomplete, response was noted.
Langerhans cell histiocytosis includes three separate conditions: eosinophilic granuloma, Hand-Schüller-Christian disease, and Letterer-Siwe disease. These are various expressions of a single disease process due to Langerhans cell proliferation. There is no general agreement as to whether
Long-standing Eczematous Anogenital Plaque. Arch Dermatol. 1993;129(12):1607-1612. doi:10.1001/archderm.1993.04540010087012