[Erdheim-Chester disease: an aggressive systemic disease treated with cladribine with favorable outcome (a case report)].

Erdheim-Chester disease (ECD) is a form of non-langerhans histiocytosis mainly affecting men, whose pathophysiology is poorly understood. Clinical picture is heterogeneous. The presence of hair kidney sign on Ct scan is pathognomonic. Diagnosis is based on anatomopathological examination. We here report the case of a 50-year old patient presenting with disorders of equilibrium and slow speech as well as general health deterioration Clinical examination showed cerebellar ataxia. Radiological and pathological investigations showed aggressive systemic ECD. cladribine-based treatment was initiated with satisfactory outcome. ECD is an extremely rare disease. Systemic forms are generally associated with poor prognosis and are refractory to treatment, unlike in the case of our patient who was treated with cladribine with good outcome.