Erdheim-Chester Disease: Histopathological Perspective of a Rare Condition

Erdheim-Chester disease (ECD) is a rare, multisystem non-Langerhans cell histiocytosis of unknown etiology with characteristic radiological and histopathological features. It usually affects middle-aged individuals with slight male predominance. Radiologically symmetrical sclerotic lesions are seen mainly in the long bones. The histopathological hallmark is infiltration by foamy histiocytes at multiple sites of involvement. Immunohistochemistry (IHC) with CD68 confirms the diagnosis. This case report describes the case of a 60year old Indian male who presented with complaints of cerebellar ataxia with chorea and autonomic involvement. Radiological and histopathological investigations confirmed ECD with multisystem involvement, involving- CNS, skeletal, pulmonary, cardiovascular, adrenal gland, lymph nodes, retroperitoneal, and perinephric soft tissue. The variable presentations require consideration and ruling out of numerous differential diagnoses such as histiocytosis X (LCH), multiple sclerosis, neuro-sarcoidosis, amyloidosis, metabolic disorders, Rosai–Dorfman disease, malignancies, and mycobacterial infections. No definitive therapy exists for ECD presently, with the prognosis being dependent on the extent and distribution of the extra-skeletal manifestations.