An Unusual Case Of Urinary Bladder Arteriovenous Malformation 

D Gnanappiragasam1 S Gnanappiragasam2 , T.E.D McDermott2

1Imperial College School of Medicine, Imperial College London, London, SW7 2AZ, UK

2Department of Urology, Tallaght University Hospital, Tallaght, Dublin 24, Ireland

Abstract

A 45-year-old male presented with haematuria and urinary frequency. Computed Tomography (CT) urogram revealed gross thickening of the left bladder wall. Histology showed large vessels cuffed by eosinophonilic material suggestive of urinary bladder arteriovenous malformation (AVM). No further intervention was carried out as symptoms resolve after the resection. Follow up rigid cystoscopy and CT at 3 months showed resolution of all visible pathology and no evidence of recurrence.

Introduction

Haematuria is a commonly encountered symptom of diverse renal tract disorders including calculus, neoplasms, trauma, infection, and rarely renovascular diseases. Arteriovenous malformations (AVMs) are relatively uncommon vascular phenomena in the urinary bladder. We present a case of AVM in a middle-aged male who presented with gross haematuria.

Case report

A 45-year-old gentleman was initially seen by General Practitioner (GP) and treated for suspected urinary tract infection with minimal improvement. Subsequently, he was referred to Emergency Department with suprapubic pain, urinary frequency and macroscopic haematuria. Computed tomography (CT) of the kidneys, ureters and bladder showed no obvious abnormalities. He presented again to his GP with progressive clot haematuria and on-going suprapubic pain.

Six weeks after initial presentation, he was seen in the urology department. Physical examination and vital signs were unremarkable. Urinalysis showed positive haematuria and no leucocytes. The patient had no previous history urinary tract infections, renal calculus or any history of trauma. Contrast CT Urogram showed a gross thickening with stranding along the left side of the bladder consistent with the tumour. However, there was no ureteric filling defects or hydronephrosis noted. Transurethral resection of the bladder confirmed findings of aggressive looking invasive tumour extending over left lateral wall to dome and was partially resected.

There were considerable disparity between the radiological and histological features and this was deemed an atypical presentation for AVM. Re-resection of bladder tumour and Magnetic Resonance Imaging (MRI) were performed to clarify the diagnosis. MRI of the pelvis showed marked irregular thickening of the left lateral and anterior walls of the bladder with an apparent stranding of the perivesical fat. On the repeat histology, there were evidence of reactive urothepithelium, inflammatory granulation tissue and patchy stromal necrosis. There was no neoplasm or any vascular features found similar to the previous specimen. Given the improvement in patient’s symptoms and the clinical stability, no additional interventions were carried out. At the three-month follow up, the patient had no recurrence of haematuria or features of AVM on the surveillance rigid cystoscopy and CT.

Discussion

AVMs are extremely rare and there have been less than 20 cases reported in the literature. Many urinary bladder AVMs are diagnosed as incidental findings on clinical imaging when investigating persistent microscopic haematuria. It’s believed that gross haematuria is a late manifestation and reflects the natural course of urinary bladder AVM.

CT or MRI scan is beneficial to demonstrate vascular nature of a lesion and to evaluate the extent of the disease1. In our hospital, the current CT Urogram protocol comprises plain, nephrogenic and pylogenic phase images. This is streamlined towards the diagnosis of the more common causes such as calculi and tumours. Angiography or arterial phase as part of CT Urogram has an added value in outlining flow characteristics of lesions, feeding vessels, draining veins and can often be therapeutic2. The management of urinary bladder AVMs are dependent upon multitude of factors such as size, location, and risk of complications. Minimally invasive percutaneous transarterial embolization is considered to be the first line treatment for symptomatic urinary bladder AVMs3. Although transurethral resection of the AVM may carry a risk of bleeding and potential injury to adjacent organs, this approach may work well for small AVMs4.

This particular case demonstrates the diagnostic difficulty in investigating the cause of haematuria. In this case, AVM was regarded to be the cause of haematurua, despite initial evidence of likely tumour. It’s imperative that AVMs are considered as a possible diagnosis at an early stage in view of the short chronology of the disease and the possibility of early deterioration. Furthermore, long-term surveillance is required to monitor recurrences of AVMs in such patients5.

 

Acknowledgment

Written consent was obtained from the patient prior to the submission.

 

Conflict of interest

The authors declare no conflict of interest.

 

Correspondence

Dushyanth Gnanappiragaam, Imperial College School of Medicine, Imperial College London, London, SW7 2AZ, UK

Email: dushyanth28@hotmail.com

 

References

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4 Smaldone MC, Stein RJ, Cho J, Leng WW. Giant idiopathic renal arteriovenous fistula requiring urgent nephrectomy. Urology 2007;69:576. e1-576. e3.

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