Introduction: Langerhans Cell Histiocytosis (LCH) is a rare disease, more common in children than in adults, resulting from aberrant proliferation of Langerhans cells, belonging to the monocytemacrophage system.
Case history: We present the case report of a 40-year-old man with a 16-year history of polyuria, polydipsia and tiredness. For 10 years he had perianal, groin, abdomen and scalp scarring, hyperpigementation along with follicles and pustules. Skin biopsy confirmed LCH. Twenty-four hour urine volume excretion was over 4 l and water deprivation test confirmed diabetes insipidus (DI). He also had secondary adrenocortical insufficiency (short synacthen test: baseline and 30-min cortisol, 92 and 263 nmol/l respectively) and hypogonadotrophic hypogonadism (FSH, LH were 1.0 and 0.4 IU/l respectively; Total testosterone 3.9 nmol/l). IGF1 was low (8 nmol/l; NR 1247). Thyroid function tests and serum prolactin level were normal. Magnetic resonance imaging (MRI) scan of the pituitary confirmed loss of high signal of the posterior pituitary on T1 enhancement and marked enhancement of the hypothalamus. Although lung function tests revealed restrictive pattern, High Resolution CT scan of the chest excluded pulmonary involvement. DEXA scan revealed osteopenia (lumbar spine and left femoral neck, T score −2.1 and −1.9 respectively). He was treated with desmopressin, oral hydrocortisone and testosterone, with significant improvement of symptoms. Radiotherapy was considered but was deferred as subsequent MRI scan showed improvement of the hypothalamic lesion.
Conclusion: Hypothalmo-pituitary axis involvement occurs in up to 50% of patients with LCH; unexplained skin and mucosal lesions of the scalp and intertriginous areas with polyuria should prompt clinicians to consider this condition. Although DI is the earliest and commonest pituitary manifestation (25%) of LCH, up to 20% may have anterior pituitary involvement; long-term follow up is needed to detect endocrine deficiencies.