CT findings. U, urinary bladder; T, tumor (GIST); C, subcutaneous cavity. Tumor was located between abdominal wall (A) and urinary bladder (E) before sunitinib therapy. Abdominal tumor was smaller on day 4 of fourth course of sunitinib (B and F). Vesicocutaneous fistula bridged by subcutaneous cavity at onset of abdominal pain (C and G). Small opening (arrow) at anterior bladder wall. Air collected in urinary bladder. Fistula healed after sunitinib discontinuation (D and H) and subcutaneous cavity became smaller.