Brain images in ECD. (A) Axial post contrast brain MRI showing suprasellar and cerebellar involvement in a patient with ECD. (B) Sagittal post contrast brain MRI (from panel A) showing suprasellar and cerebellar tumors in a patient with ECD. (C) Axial fluid attenuated inversion recovery brain MRI showing ECD tumors in cerebral hemispheres. (D) Axial fluid attenuated inversion recovery brain MRI showing ECD tumors in cerebral hemisphere. (E) Sagittal post contrast brain MRI showing an ECD tumor with cystic components in the midbrain-pons of a patient with ECD. (F) T2 fluid attenuated inversion recovery MRI image showing increased symmetrical signal intensity in the cerebellum. (G) Neurodegeneration and atrophy of the cerebellum in a patient with ECD seen on brain MRI. (H) Orbital involvement with tissue accumulation in the intraconal space secondary to histiocytes accumulation in ECD. (I) Orbital involvement showing increased thickening of the lateral rectus muscle. (J) Pituitary stalk is thickened secondary to macrophage accumulation in ECD and deviated to the right. (K) Hematoxylin and eosin stain for brain lesion showing foamy macrophages and inflammation in brain mass biopsy specimen (original magnification ×40). (L) CD68 KP-1 stain of panel K highlighting the foamy macrophages (original magnification ×40).