A heterogeneous T2 hyperintense mass replaces much of the sacrum. The mass possesses fairly circumscribed hypointense margins with lobulation, mild patchy enhancement and extensive areas of restricted diffusion.
The sacral canal and all sacral foramina, except the right ventral S1 foramen, are obliterated within the mass. The anterior aspect of the mass slightly compresses the posterior aspect of the mid to lower rectum, with preserved intervening fat.
No size-significant intrapelvic or inguinal lymphadenopathy.
Persisting mild oedema of the erector spinae muscles at the L5 and S1 levels.
Indwelling catheter within the urinary bladder.