Presacral retroperitoneal rounded well-defined mass displacing the rectum and the rectosigmoid junction anteriorly with preserved presacral fat.
The mass measures 10 x 10 x 9.5 cm with a predominant hypointense signal at the periphery and central stellate hyperintense areas on T2WI. No opposed phase signal drop (not shown). A profoundly hypointense focus at the periphery, likely an area of calcification. Heterogeneous enhancement of the peripheral mass on the post-contrast images, with a hypovascular swirling-shape central area corresponding to the hyperintense stellate area on T2WI. Diffusion restriction in the periphery.
The uterus and ovaries are unremarkable.
Differential diagnosis includes gastrointestinal stromal tumor (GIST), solitary fibrous tumor of the retroperitoneum, or neurogenic tumor (less likely).