A rare case of Erdheim-chester disease reported from Nepal

INTRODUCTION: Erdheim-Chester Disease (ECD) is a rare non-Langerhans cell histiocytosis with a propensity to involve multiple organs. CASE PRESENTATION: We report a case of a patient in mid-60s with occipital headache and ataxia. Following the radiological and immunohistochemical investigations and genomic studies, a diagnosis of ECD was made with two intracerebral lesions. Brain lesions were resected and the patient was discharged with the medication Vemurafenib. After 3 years of diagnosis and 13 years of initial presentation, patient passed away. DISCUSSION: ECD frequently presents with Diabetes Insipidus as initial presentation, long bone osteosclerosis as the most common presentation, and has multi-system predisposition. ECD can be differentiated from Langerhans Cell Histiocytosis (LCH) with immunohistochemistry images of the biopsy specimens. Further, with genomic analysis of ECD, the neoplastic nature has been highlighted and targeted therapies like Vemurafenib and Cobimetinib are shown to be effective. CONCLUSION: Good clinical judgement and supporting investigations can aid in diagnosing rare entities like ECD even in resource-limited settings.