Causes of haematuria in adult polycystic kidney disease

Patients with a chronic disease may develop new, but often related, symptoms. The assumption, however, that all symptoms are related and need no further investigation, may result in the misdiagnosis of a serious disease. Autosomal dominant polycystic kidney disease is a common inherited condition, occurring in between 1 in 200 and 1 in 1000 of the population.¹ After diagnosis patients are followed up by nephrologists because of the risk of progression to end stage renal failure. Renal function may be preserved, however, and outpatient attendance is often infrequent. If complications develop, affected individuals may present to primary care providers or a wide range of hospital and surgical specialties, where staff should be aware of possible diagnostic difficulties. Macroscopic haematuria is a common complication that is usually related to the polycystic kidney disease.² We present two cases where subsequent investigations discovered bladder carcinoma and suggest possible screening methods.

Case reports

Case 1—A 49 year old man with adult polycystic kidney disease and persistent microscopic haematuria since diagnosis nine years earlier, presented with a three week history of asymptomatic macroscopic haematuria. He was otherwise well with no reported anorexia or weight loss. Multiple urine cultures were sterile. Ultrasound scanning of the renal tract showed a three centimetre mass at the base of the bladder. At cystoscopy a papillary pT1 G2 tumour at the bladder neck was resected. There was no histological evidence of carcinoma in situ. The patient is currently undergoing treatment with intravesical BCG and remains well.

Case 2—A 34 year old woman with adult polycystic kidney disease was reviewed in the outpatient department shortly after she became pregnant. She was asymptomatic with no macroscopic haematuria, but a substantial number of red blood cells were discovered on microscopic urine examination. She had had several intermittent episodes of painless macroscopic haematuria for five years. These had settled with no intervention, and at her regular outpatient attendance the presence of haematuria had not been detected on urine dipstick or microscopy. Renal tract examination during fetal ultrasound scanning at eight weeks' gestation showed a non-mobile, lobulated soft tissue mass in the bladder. At cystoscopy a pTa G2 carcinoma was completely resected. No further specific treatment was indicated. The pregnancy continued to term, and the baby was delivered without complication.

Discussion

Almost two thirds (64%) of people with adult polycystic kidney disease also develop microscopic or macroscopic haematuria.² Most episodes are due to urinary tract infections and renal cyst rupture that relate to the underlying anatomical abnormalities. The symptoms are usually short lived³ and resolve with conservative measures such as rest and antibiotic treatment. Renal stone disease is also common, occurring in 20% of patients.⁴ However, macroscopic haematuria is also a presenting symptom of common, but unrelated, disorders that may occur coincidentally. For example, a woman with dysuria and suprapubic discomfort in association with haematuria may be diagnosed with cystitis; or acute prostatitis may present in men with low back pain and fever. In the absence of an obvious unrelated cause, symptoms are often assumed to be due to the chronic disorder. Serious coincident diagnoses may be overlooked, which would lead to a delay in treatment. We have described two patients with polycystic kidney disease and bladder carcinoma. The clinical presentation of renal tract cancer is similar to the other, more common complications of polycystic kidney disease,⁵ and the incidence of these malignancies matches that of the general population.⁶ With these points in mind, how should one effectively screen this group of patients who develop haematuria for underlying urothelial malignancy?

In the general population, standard investigations for haematuria include urinary microscopy, cytology testing, intravenous urography, and ultrasound scanning. These identify an upper renal tract malignancy in less than 1% of screened patients. Cystoscopy detects bladder carcinoma in 12%.⁷ Detection rates of malignancy in polycystic kidney disease are likely to be lower as the incidence of benign pathology is much higher. Macroscopic haematuria is frequently recurrent,³ which could result in repeated investigation. Both our cases of bladder carcinoma were diagnosed after transabdominal ultrasound scanning. This is a useful detection method for larger bladder tumours, but the yield is proportional to tumour size.⁸ Urine cytology may be a useful adjunct for high grade bladder cancer, but sensitivity is poor in detecting low grade malignancy.⁹,¹⁰ For upper renal tract cancers ultrasound scanning and intravenous urography are difficult to interpret in adult polycystic kidney disease, and enhanced computed tomography scanning of the abdomen is the radiological investigation of choice.¹¹

We have reported two cases of bladder carcinoma manifesting as macroscopic haematuria in adult polycystic kidney disease. These cancers can also be associated only with microscopic haematuria, and this further emphasises the need for continued vigilance. Underlying malignancy should be considered in patients with associated abdominal pain, weight loss, or constitutional symptoms,⁵ irrespective of age. Indeed, the second case provides further evidence that bladder carcinoma is not exclusively a disease of those aged more than 40 years,⁷ so screening protocols should include younger patients.

Routine screening for underlying urothelial tumours among all patients with adult polycystic kidney disease who also have episodes of haematuria is probably untenable. Simple non-invasive investigations such as transabdominal scanning and urine cytology may be viable, and these could easily be requested before referral to the appropriate specialty. Further studies are needed to assess whether such a routine screening protocol would be cost effective and whether there is a cohort of high risk patients who would benefit from more intensive investigation.

Do not assume that haematuria in association with adult polycystic kidney disease is always benign