LAUSR

OBJECTIVE Langerhans Cell Histiocytosis (LCH) is a rare inflammatory myeloid neoplasm which can infiltrate any organ or tissue. Endocrine involvement has mostly been described in case reports and small retrospective studies. We aimed to describe endocrine manifestations in a large cohort of adulthood onset (AO) and childhood onset (CO) patients with LCH. DESIGN single-center observational study conducted between January 2002 and December 2017 at Pitié-Salpêtrière University Hospital (Paris, France), a tertiary care hospital. METHOD Clinical, biological and morphological evaluations of pituitary, gonadal, adrenal, and thyroid function evaluations performed in 63 consecutive patients with LCH (AO patients:40, CO patients:23). Fifty-eight patients underwent follow-up assessments. RESULTS Complete pituitary evaluation was performed in 38/63 patients (60.3%); at least 1 anterior pituitary dysfunction (APD) was found in 63.2% of them. In this subgroup of patients, the most prevalent deficiencies were diabetes insipidus (DI,) and GHD (55.3% each), followed by gonadotropin deficiency (34.2%) and thyrotropin deficiency (23.7%). In the subgroup of the 25 incompletely evaluated patients, we found DI in 44%, GHD in 50%, gonadotropin deficiency in 30.4% and thyrotropin deficiency in 16%. APD was more common in CO patients (p=0.003) but was not systematically associated with DI regardless of the age of onset. Endocrine dysfunction was most often permanent; moreover, occurrence of new deficiencies has been described during follow-up. CONCLUSION The spectrum of endocrine disorders appears to be large in LCH (both in AO and CO patients) and should be evaluated carefully at diagnosis and during follow-up. APD was not always associated with DI.