Figure 9c. Lipomatosis of the median nerve in a patient without macrodactyly. (a) Axial T1-weighted (783/15) MR image of the wrist shows marked thickening of the median nerve with adipose tissue surrounding the nerve fascicles (arrowheads). (b) Longitudinal sonogram of the wrist also reveals cablelike thickening of the median nerve fascicles (arrowheads) with intervening hyperechoic fat. (c) Intraoperative photograph of the wrist dissection demonstrates a diffusely thickened, yellow median nerve (arrow) resulting from the lipomatosis of the nerve. (d) Photomicrograph (original magnification, x200; H-E stain) shows diffuse lipomatous infiltration (L) of the surrounding nerve fascicles (N).