A rare cause of central diabetes insipidus with arthritis (Erdheim-Chester disease)

Abstract

Mr. Haider is a 26-year-old resident doctor who presented with intermittent fever relieved by NSAIDS fatigue, weakness, loss of libido, fever with no rigor, night sweat, bone, joint pain and knee swelling. He lost weight. He was diagnosed with central chronic D.I for the last 3 years after several weeks history of polyurea and thirst without identifiable cause which follows elbow fracture with trivial trauma and was taking nasal desmopressin as required Suspicion of inflammatory or infiltrative lesion of pituitary was raised. For proximal tibial lesion bone biopsy was done and revealed marked fibrosis with infiltration of bone marrow by foamy cells with multinucleated cells positive for CD 68 and negative for CD 1a by immunohistochemistry. Further evaluation by PET scan confirms the diagnosis and shows multifocal hypermetabolic symmetrical bone lesions most intense around elbows and knees consistent mostly with Erdheim Chester disease (ECD).