Fig. 12
From: What is hiding in the hindgut sac? Looking beyond rectal carcinoma
Primary amelanotic anorectal melanoma. a, b Axial T2-weighted MRI reveals fungating intraluminal mass (arrow) with a large perirectal deposit (arrowhead). c Sagittal T2-weighted MRI demonstrates the polypoidal mass (arrow) expanding the rectum and the large perirectal deposit (arrowhead). d Axial T1-weighted post contrast MRI reveals heterogeneous enhancement of the mass (arrow) and the deposit (arrowhead)