Fig. 1

Colonic histology, MR enterography, and MRI brain for Patient 1 (a-g). (a) Colonic biopsy showing active inflammation in keeping with panproctocolitis, H&E stain, magnification × 40. (b) Colonic biopsy showing focal atrophic changes within the smooth muscle cells of the muscularis mucosa, including intracytoplasmic vacuoles, pyknotic nuclei and eosinophilic degeneration of the cytoplasm, H&E stain, magnification × 200. (b-e) Coronal contrast MRI of the small bowel demonstrating a 2 cm segment of terminal ileum with mild mural thickening (c), mural oedema on T2 sequence (d), intermediate enhancement with gadolinium (e), and separation of bowel loops in the distal ileal mesentery suggesting fat proliferation. (f) Axial brain flair MRI taken during the acute admission, showing extensive confluent, symmetrical white matter hyperintensity in both cerebral hemispheres, which does not show restricted diffusion. This extends from the periventricular to the subcortical regions but sparing the U-fibres. (g) Follow-up axial brain flair MRI with contrast, at six weeks post-discharge, showing no change in the extent of diffuse periventricular and subcortical white matter hyperintensity