The Langerhans Cell Histiocytosis (LCH) Adult Clinic is part of the department of medical research, and consists of a multidisciplinary collaboration of several subspecialties concerning patients with LCH and Erdheim Chester Disease (ECD). The LCH Adult Clinic is located at the 251 Hellenic Air Force & VA Athens General Hospital which is one of the 3 largest military hospitals in Greece and provides general and tertiary services for the wide geographical area of Attica while it accepts referrals from all over Greece. The LCH adult clinic at the 251 Hellenic Air Force & VA Athens General Hospital delivers leading care for adult patients suffering from LCH and ECD by providing: access to optimal and complete care, supporting programmes and scientific innovations for every patient. In addition, all treatment plans are in keeping with international standards of care for these disorders. Lead and coordinator of the LCH Adult Clinic is Dr P. Makras who is a founding member of the European Consortium for Histiocytosis (ECHO), member of the Histiocyte Society, and member and expert physician of the Histiocytosis Association. Additionally, Professor G. Kaltsas is a co-supervisor of the LCH Adult clinic and shares the same years of experience and memberships with Dr P. Makras as he is co-founder of this clinic, acting also as a direct link with on of the largest Hospitals in Greece namely “Laiko” Hospital, which is affiliated to the National and Kapodistrian University of Athens. The LCH Adult clinic has the required infrastructure which includes signed contracts among all relevant disciplines, including the main partners (Haematology, Endocrinology, Internal medicine, Oncology, Nuclear Medicine, Radiology, Orthopedic surgery, Pneumonology, Dermatology, and Histopathology). Secondary partners include Surgery, Cardiology, Nutrition Service, Psychological Services and others. All our multidisciplinary partners have extended experience in the field of LCH. The LCH Adult clinic runs at least once monthly an LCH/ECD Specialist Multidisciplinary Team (MDT), pending on the number of patients needed to be discussed. In these meetings all new patients are discussed as well as all other LCH and/or ECD patients in case of disease progression, need for treatment modifications, patient’s request or for other related reasons if required. All disciplines involved in the center follow standard operation procedures (SOPs). The LCH Adult clinic organised and currently runs a phase IIa clinical study regarding a new treatment modality in LCH (NCT03270020) and has published multiple original research and review papers in international medical journals. In addition, it is in close collaboration with other LCH centers across Europe and USA.