Extensive basal cell carcinoma and disseminated lesions in Hand-Schüller-Christian disease.

Sir, Langerhans’ cell histiocytosis (LCH) includes four clinical entities with a common characteristic of infiltration of LC in different tissues. Biopsy of suspicious lesions and staining for CD1a and S100 protein or antilangerin are needed to establish a definitive diagnosis of LCH. Electron microscopy to identify Birbeck granules is performed less frequently because of time and cost constraints (1, 2). The pathogenesis remains unclear. A neoplastic aetiology has been suggested due to the existence of a single clone in the infiltration, although no cytogenetic abnormalities have been found (3, 4). Most investigators consider LCH to result from an immunological dysfunction (2, 5, 6). The presence of aggregates of other immunologically active cells, decreased numbers of suppressor T lymphocytes and high levels of cytokines in the lesions suggest an exaggerated physiological response of LC to an antigen, or an appropiate response to abnormal signals from other immune cells (1, 7, 8). Although numerous facts are known about the cell mediators, it has not been possible to prove the participation of any factor in the unchaining of the clonal proliferation of the cells in the LCH (9). We present here a new case of basal cell carcinoma (BCC) in association with one type of LCH, HandSchüller-Christian disease, with a probably late specific cutaneous infiltration of the LC.