Langerhans cell histiocytosis (LCH) is characterized by idiopathic monoclonal infiltration of Langerhans cells in different organs such as the skeleton, skin, pituitary gland, liver, spleen, lungs, and the hematopoietic system. Skin lesions are common in LCH and affect about 40% of cases. It is reported that skin lesions are usually the first manifestation of LCH in 80% of patients. Usually, cutaneous presentations of LCH in adults are generalized or seborrhea-like lesions and it is often the first manifestation of disease. Here, we describe a 45-year old female who was known case of hypothyroidism, systemic lupus erythematosus, and diabetes insipidus. In our patient, cutaneous involvement was unusual. It was single and presented in unusual site (ankle) and before developing such lesion, she had diabetes insipidus for several years due to the involvement of pituitary gland.