Endocrine Abstracts

Background: Langerhans cell histiocytosis (LCH) is an uncommon myeloproliferative disorder characterised by inflammatory lesions and accumulation of histiocytes leading to the destruction of affected tissues. LCH has a variable presentation and can occur as a single indolent lesion or can affect multiple organs such as the pituitary gland, bones, CNS, liver, lungs, lymph nodes, spleen, skin, heart and gastrointestinal tract. LCH of the pituitary gland most commonly presents with arginine vasopressin deficiency (AVP-D).

Case Presentation: A 61 year old lady presented to dermatology in 2017 with two vulval lesions which were excised. Histology confirmed LCH. 16 months later she presented to endocrinology with an 8 month history of thirst and polydipsia. Her water deprivation test was consistent with AVP-D and pituitary MRI showed thickened pituitary stalk. Desmopressin was commenced. On recommendations of the specialist histiocytosis centre, oral mucosa and teeth were carefully examined. A history of intermittent oral ulcerations affecting the mouth floor, tongue and gingiva was elicited. Oral mucosa biopsy confirmed LCH leading to a diagnosis of multisystem disease. FDG PETCT revealed avid foci within the iliac bone and cervical lymph nodes progressing to multiple bone sites during follow up. She was managed with Prednisolone, Mercaptopurine and Methotrexate, the latter stopped after a severe chest infection. In 2020 she developed secondary hypogonadism and osteopenia. Attempted taper of medications in 2022 was unsuccessful leading to disease relapse.

Discussion: Multisystem LCH in adults is rare. There is no consensus on the optimal treatment and most of our understanding and management is derived from paediatric literature. Our case illustrates the course of the disease over a six year period and the importance of thorough oral examination that can reveal multisystem involvement necessitating systemic therapy. LCH should be considered in patients presenting with AVP-D with a history of recurrent oral or vulval ulceration.