Demographics and most frequently observed CNS imaging features of ECD, RDD, and LCH

	ECD	LCH	RDD
Demographics	M>>F, 50–70 yrs	M > F, 1–3 yrs	M > F, young adults
Presentation	Commonly asymptomatic; CNS involvement leads to diabetes insipidus, pontocerebellar symptoms, and seizures	Nonspecific, including lethargy, fever, bone pain, diabetes insipidus	Lymphadenopathy, night sweats, weight loss
CNS imaging	Patchy enhancement and T2 hyperintensity in the posterior fossa; enlargement and enhancement of the pituitary stalk; loss of posterior pituitary T1 signal; intra- and extra medullary spinal lesions	Enlargement and enhancement of the pituitary stalk; loss of posterior pituitary T1 signal; neurodegenerative changes in the basal ganglia, pons, and dentate nuclei; parenchymal atrophy	Enlarged cervical lymph nodes; enhancing dural-based masses that mimic meningiomas

Note:—M indicates male; F, female.