Intracranial mass lesions and skin discoloration in the armpits as unusual clues to Erdheim-Chester disease: a case report

BACKGROUND: Erdheim–Chester disease (ECD) is a non-Langerhans histiocytosis that results in multi-organ disease involving the skin, bones, lungs and kidneys. Central nervous system (CNS) involvement occurs in about 50 % of patients, and diabetes insipidus, visual disturbances, and cerebellar ataxia are the most frequent neurological signs. We report a case of Erdheim-Chester disease with central nervous system involvement in the form of enhancing intracranial mass lesions with massive edema. CASE PRESENTATION: The patient presented with vertigo, ataxia, encephalopathy and pyramidal signs. Diagnosis was suggested by xanthomatous skin lesions and a biopsy was compatible with Erdheim-Chester disease demonstrating xanthogranulomas CD68 positive (clone KP1) and CD1a and S100 negative. Testing for BRAF mutation was negative, which precluded treatment with Vemurafenib. Treatment with steroids and interferon resulted in improvement of neurological signs and regression of edema on MRI. CONCLUSIONS: The diagnosis of Erdheim-Chester disease should be considered in intracranial mass lesions. Xanthomatous skin lesions are a clue to the diagnosis.