Erdheim-Chester Disease Revealed by Central Positional Nystagmus: A Case Report

Advances in Understanding and Management of Erdheim-Chester Disease

Erdheim Chester Disease (ECD) is a rare histiocytic disorder marked by infiltration of organs with CD68+ histiocytes. ECD stems from mutations of BRAF and MAP2K1 in hematopoietic stem and progenitor cells (HSPCs), which further differentiate into monocytes and histiocytes. Histopathology reveals lipid-containing histiocytes, which test positive for CD68 and CD133 in immunohistochemistry. Signs and symptoms vary and depend on the organ/s of manifestation. Definitive radiological results associated with ECD include hairy kidney, coated aorta, and cardiac pseudotumor. Treatment options primarily include anti-cytokine therapy and inhibitors of BRAF and MEK signaling.

Multiple Nervous System Involvement of Erdheim-Chester Disease With Responsive Perinephritic Hypermetabolism

ABSTRACT

A 36-year-old man who was at follow-up for histiocytosis had sudden-onset symptoms of unilateral ophthalmic increased pressure. The patient was referred to the FDG PET/CT for determination of involvement with suspicion of Erdheim-Chester disease. The reduction of the FDG uptake in all of the lesions (medial temporal lobes, nasal septum, medulla spinalis in sacral region, as well as perinephritic infiltrations), which were determined by the first PET/CT, was achieved at second imaging.

Novel paraneoplastic mechanism for cerebellar ataxia in Erdheim-Chester disease

We report a case of BRAF-mutation positive Erdheim-Chester disease presenting with a cerebellar ataxia. This is the first such case to be reported without structural MRI abnormalities but with a single intrathecally produced oligoclonal band. Now that the histiocytoses have been recharacterised as neoplastic, we speculate that the mechanism of the ataxia in our case is paraneoplastic. We highlight the importance of searching for BRAF mutations in this disease, as their presence leads to effective personalised treatments.