Summary of the CNS imaging findings in Erdheim-Chester disease (reported prevalence in parentheses)
| Compartment | Imaging Finding |
|---|---|
| CNS involvement (25%–76%) | Parenchymal volume loss (cortical and cerebellar atrophy), increased radial diffusivity of water molecules |
| Parenchyma (supratentorial [approx. 46%]; posterior fossa [20%–46%]; white matter [60%–87%]; basal ganglia [7%]) | Scattered lesions (micronodular, nodular, masslike), T2 prolongation, heterogeneous enhancement, minimal edema, increased Ktrans values |
| T2/FLAIR hyperintense lesions of indeterminate significance | |
| May have signal drop-out on SWI in basal ganglia | |
| Prolonged gadolinium contrast retention | |
| HPA (17%–44%) | Thickening of pituitary stalk, hypothalamic T2 hyperintensity |
| Loss of posterior pituitary bright spot, nodular or micronodular lesions, pituitary atrophy | |
| Vascular (10%–17%) | Periadventitial vessel inflammation, vascular sheathing |
| Dural venous sinus thrombosis or infiltration | |
| Extra-axial (dural [30%–50%], leptomeningeal [6%–7%]) | Dura-based solitary or multiple lesions (enhancing, isointense), pachymeningeal thickening, spinal extradural involvement |
| Leptomeningeal disease | |
| Craniofacial (40%–50%) | Osteosclerotic lesions (calvaria, skull base, paranasal sinuses), bone thickening |
| Orbital (18%–30%) | Intraconal or extraconal masses |
| Optic nerve sheath enlargement | |
| Choroidal involvement (intraorbital mass) |