Erdheim-Chester Disease: A Case Report Exploring Multisystemic Involvement.

Erdheim-Chester disease (ECD) is a rare, multisystemic, non-Langerhans cell histiocytic neoplasm predominantly affecting middle-aged males in their fifth to seventh decades of life. It often presents with nonspecific symptoms, leading to a delay in its diagnosis. We report a case of an 85-year-old male with multisystemic manifestations, including retroperitoneal, skeletal, vascular, cardiac, orbital, and central nervous system (CNS) involvement. Imaging revealed characteristic findings such as bilateral osteosclerosis, perirenal infiltration (hairy kidney sign), and dural-based intracranial masses. Histopathological analysis confirmed the diagnosis, identifying CD68+ histiocytes and the BRAFV600E mutation. The patient was managed initially by Internal Medicine and later referred to Hemato-Oncology for further treatment. This report highlights the importance of maintaining a high index of suspicion for this rare disorder, as well as adopting a multidisciplinary approach toward its treatment, integrating clinical, radiological, and histopathological data.