Figure 1.

66-year-old female undergoing treatment with bevacizumab and FOLFOX (folinic acid, fluorouracil and oxaliplatin), for locally recurrent rectal carcinoma at the site of the surgical anastomosis. The patient developed right hip pain, caused by perforation at the site of recurrence. (a) Pre-treatment axial contrast-enhanced CT of the pelvis demonstrates a soft tissue mass (arrows) in the pre-sacral space close to the surgical anastomosis (arrowhead), representing the site of tumour recurrence. (b) Non-contrast CT of the right hip after commencement of therapy and symptoms reveals a fistulous tract containing oral contrast (arrows) extending from the pre-sacral mass into the right gluteus medius muscle. Several locules of air (arrowheads) are also seen in the right gluteus medius muscle.