Teaching NeuroImages: Brain and Skin Involvement in Erdheim-Chester Disease

A 61-year-old man developed progressive gait imbalance and papular skin lesions over 9 months. He reported fatigue, but no other constitutional symptoms. Neurologic examination revealed ataxia. Brain MRI (figure 1, A–D) demonstrated punctate enhancing foci supratentorially patchy pontine T2 hyperintensity; pituitary or orbital abnormality was reported. Skin biopsy 2) a histiocytic neoplasm that stained negative for CD1a, weakly positive S100, CD163, factor 13A, BRAF V600E, compatible with Erdheim-Chester disease.1 Bone scan body PET did not demonstrate osseous, cardiac, lung, retroperitoneal involvement. Vemurafenib prescribed disease brain involvement.2 involvement occurs in up to half of patients most often manifests radiographically as cerebellar hyperintensity, although multifocal enhancement has also been reported.3,4 is observed approximately one-quarter are commonly xanthelasma-like, nonfacial cutaneous xanthoma-like seen our patient may occur.5 On follow-up 4 months later, the patient's had flattened, gadolinium resolved, hyperintensity nearly resolved E F), persisted.