Visual vignette

A previously healthy 22-year-old man presented with headache, altered mental status, polyuria, and hypernatremia is presented. Magnetic resonance imaging of the brain revealed a hypothalamic mass that had infiltrated the pituitary stalk. Laboratory evaluation confirmed the presence of panhypopituitarism and central diabetes insipidus, and treatment was initiated with hydrocortisone, levothyroxine, and desmopressin. After seven months, the patient presented with purulent discharge from his left ear. A computed tomographic scan of the basal skull showed prominent demineralization and bony destruction throughout the left mastoid bone, consistent with mastoiditis. Langerhans cell histiocytosis (LCH) is characterized by the abnormal proliferation of specific histiocytes known as Langerhans cells. This process results in inflammatory lesions that can cause damage to the hypothalamus, pituitary gland, bones (lytic lesions), skin, lymph nodes, oral mucosa, lungs, liver, and spleen.