Case 1

This is a CT study of the abdomen, showing a round, heterogenous, well defined heterogeneous density mass with high density serpiginous structures within. It lies between the rectum and the urinary bladder, exerting mass effect and displacing the bladder laterally to the right side.  

The serpiginous lines exhibit uniform thickness and density, indicating that this is a foreign body rather than a natural endogenous structure.

The mass shows no enhancement on the post contrast images.

There is bilateral marked hydronephrosis and hydroureter, due to extrinsic obstruction of both ureters in the pelvis by the mass. The left kidney shows cortical thinning and atrophic changes due to longstanding obstructive nephropathy. The urographic phase images show retention of contrast and slow flow in the dilated right ureter, and no contrast flow in the left ureter indicating more complete obstruction and reduced function of the left kidney.

The features are in keeping with a pseudotumour forming around a retained surgical mesh, or a gossypiboma. This is causing bilateral obstructive nephropathy by extrinsic compression on the lower segments of both ureters.

I would ask about the patient’s previous surgical history, in particular if they have had abdomino-pelvic surgery in the past.

I would recommend relieving the kidneys by placing bilateral nephrostomy catheters in the first instance; I would then raise this case for discussion at surgical / urology MDT - surgical management is likely.