Summary
A 91‐year‐old woman presented with an itchy, erosive and scaly eruption of about 2 years duration. Clinical, histological and ultrastructural examination of the skin lesions showed typical changes due to Letterer‐Siwe disease.
Large mononuclear cells with deeply idented or convoluted nuclei and with Langerhans' cell granules in the cytoplasm, were found to invade the superficial dermis, epidermis and dermo‐epidermal junction.