Pseudo-subphrenic abscess.

The presence of a subphrenic abscess can be established by its soft tissue mass effect especially when it contains gas. In the five patients presented here, gas-containing subphrenic abscesses were mimicked by air in loops of ileum; partially loculated air due to subphrenic adhesions in the post-laparotomy patient; layering of denser barium below with gastric content above in a patient with gastric outlet obstruction; and gas in the renal bed after nephrectomy.