Retroperitoneal fibrosis mimicking prostate cancer

Retroperitoneal fibrosis typically affects the region extending from the second lumbar vertebra to the pelvic brim. Where it extends below the pelvic brim, encasement of individual pelvic organs can mimic malignant disease.^1,2

Case history

A previously fit and well retired carpenter aged 65 was investigated after reporting painless macroscopic haematuria of short duration. The only noteworthy physical finding was a firm irregular prostate clinically compatible with a T3/T4 malignant lesion. Abdominal ultrasound showed moderate to gross bilateral hydronephrosis. CT confirmed the hydronephrosis and the irregularity of the prostate (Figure 1); in addition, CT and chest radiographs revealed extensive bilateral calcified pleural plaques typical of asbestos exposure. Prostate specific antigen was normal (1.5 ng/mL); serum creatinine was raised at 172 mmol/L and the erythrocyte sedimentation rate (ESR) was 56 mm/h.

Figure 1.

CT of pelvis

On examination under anaesthesia a distinct pelvic mass was felt at the level of the bladder base; the bladder was cystoscopically normal. Retrograde imaging showed bilateral tapering strictures of the distal ureters suggestive of external compression. Ureteric stents were inserted on both sides. Biopsies from the pelvic lesion contained dense fibrous tissue compatible with retroperitoneal fibrosis; no evidence of malignant disease was found in the pelvic mass or the prostate. Cancer having been excluded, the patient was started on prednisolone. Four and eight months later, retrograde studies showed only marginal improvement in the ureteric obstruction despite a fall in the ESR to 9 mm/h. Ureterolysis and ureteric reimplantation was planned, but had to be delayed when the patient had a major myocardial infarction.

COMMENT

Asbestos bodies have also been reported in various retroperitoneal organs, including the kidney and adrenal glands,³ and two previous case studies have reported a link between asbestos exposure and retroperitoneal fibrosis.^4,5 Uiba et al.⁶ found that patients with significant asbestos exposure (410 fibre-years) were at nine-fold excess risk with a mean latency period from first exposure of 30-33 years.⁶ Our patient had worked as a carpenter and ceramic tiler all his life, and the likely cause of his disease was occupational exposure to asbestos.

Isolated retroperitoneal fibrosis within the true pelvis is very rare, and involvement of single organs presents special diagnostic challenges. Symptoms can range from dyspareunia, when the cervix is affected,² to a change in bowel habit with rectal involvement.¹ The features can resemble those of malignant disease both clinically and radiologically. We have not found a previous case in which retroperitoneal fibrosis gave the appearance of prostate cancer. Once a malignancy is excluded, the aim of treatment is to restore normal renal function by relief of obstructive uropathy. Primary treatment with steroid therapy and ureteric stenting has been shown to be effective in most patients.⁷ Failure of medical therapy necessitates open ureterolysis.