Multisystem Langerhans cell histiocytosis (LCH) is a rare disorder that can affect multiple organs simultaneously or sequentially. In a 36-year-old patient, the disease first manifested itself as polydipsia, polyuria and dry mouth, later bone pain, facial erythema and lymph node enlargement were added. Cranial MRI showed thickening of the pituitary stalk and absence of posterior pituitary signal. Bone biopsy confirmed LCH by expression of S-100(+), CD1a(+) and CD68(+). After the start of systemic chemotherapy and DDAVP treatment, there was an improvement in polyuria, polydipsia, reduction of bone pain, regression of skin manifestations, normalization of the morphology of the pituitary stalk, and a reduction in the metabolic incidence of the lesion. The case shows that early diagnosis and treatment can lead to a significant improvement in the patient's condition.