The spectrum of endocrine abnormalities in patients with Langerhans cell histiocytosis (LCH)

Introduction: LCH is a rare, systemic disease due to monoclonal expansion of dendritic cells. The Hypothalamic – Pituitary system (HPS) is involved in 5–50% of cases, with most patients presenting with diabetes insipidus (DI); however, the majority of information is derived from studies in children. Only a few series including adult patients with LCH provide information of HPS involvement. We have evaluated the morphology and function of the HPS in 8 patients (3 males, median age 29.5 years, range, 16–57 years) with known LCH (median disease duration 11,5 years, range 0,3–22 years). Methods: All patients underwent clinical examination and basal endocrine assessment of the anterior and posterior pituitary. A dynamic endocrine test (insulin tolerance test (ITT) and/or water deprivation test) was performed for assessment of GH reserve and when basal investigations were not diagnostic. MRI scan of the HPS was performed in all patients. The form and duration of therapy that patients had received during the course of their disease was also recorded. Results: All patients had involvement of several systems. Six patients had received at least one therapeutic scheme in the past. DI was found in 7 patients (in two patients the diagnosis of DI was made at the time of assessment). Among the hormones of the anterior pituitary GH and gonadotrophin deficiency was found in 3 patients, whereas ACTH deficiency was found in another patient; no patient had TSH deficiency. Mild hyperprolactinemia was found in 2 patients. MRI demonstrated HPS pathology in 7 patients but was normal in the patient without DI; however, this patient had diffuse meningeal involvement. Conclusion: DI is very common in adult patients with LCH and is associated with structural abnormalities of the HPS on MR imaging. Such patients may also develop abnormalities of the hormones of the anterior pituitary and therefore require prolonged follow-up.