CASE REPORT Laparoscopic removal of a pelvic cyst associated with obstructed megaureter and dysplastic renal remnant Michael L. Pianezza, MD, MSC, FRCSC; Eric P. Estey, MD, FRCSC Abstract alterations in a genetic pathway important for nephron or collecting duct formation lead to abnormal development, We report a case of a 41-year-old man with a solitary function- occasionally with cyst formation, and the second caused by 1–3 ing left kidney and history of chronic pelvic discomfort associ- obstruction. Obstructive conditions associated with renal ated with lower urinary tract symptoms. Imaging revealed a large dysplasia include primary obstructive megaureter and cystic structure in the pelvis attached to a dilated tortuous ureter ureteropelvic junction obstruction.4,5 on the right with congenital absence of the right kidney. The patient Laparoscopic nephrectomy and nephroureterectomy for underwent laparoscopic removal of the pelvic cyst and dilated dysplastic kidneys are now becoming widely accepted pro- right ureter. Pathological assessment revealed mesonephric rem- cedures for the pediatric population,6–9 but are uncommon nants representing dysplastic renal tissue attached to a dilated and for the adult population. We report a case involving the obstructed megaureter, extending into the bladder wall and form- laparoscopic removal of a dysplastic kidney with a primary ing a large pelvic cyst. The patient’s symptoms resolved. A laparo- obstructed megaureter associated with a symptomatic large scopic approach represents an excellent surgical option for pelvic pelvic cyst. pathology. Can Urol Assoc J 2009;3(2):159-62 Case report A 41-year-old man presented with a several-year history Résumé of chronic, nonspecific symptoms in his pelvis and lower back. The patient also complained of urinary frequency Nous décrivons le cas d’un homme de 41 ans porteur d’un seul (15–20 times/d) and urgency. The symptoms had been pro- rein fonctionnel (gauche) et ayant des antécédents de douleurs gressing during the previous 2 years. There was no hist- pelviennes chroniques liées à des symptômes affectant les voies ory of urinary tract infections or prostatitis. The patient did urinaires inférieures. Les épreuves d’imagerie ont révélé une masse α kystique volumineuse au niveau du pelvis, une dilatation et une not respond to -blockers, antibiotics or antispasmodic sinuosité urétérales du côté droit et l’absence congénitale de therapy. The patient was known to have a solitary left rein droit. Le patient a subi une ablation par laparoscopie du kyste kidney. Physical examination revealed a benign abdomen pelvien et de la section dilatée de l’uretère droit. L’évaluation with a normal penis and normal testicles and spermatic pathologique a révélé des vestiges mésonéphriques constitués cords. Digital rectal examination revealed an increased de tissu rénal dysplasique lié à un méga-uretère obstrué avec dilata- sphincter tone and empty rectum. The prostate was mild- tion kystique se prolongeant dans la paroi vésicale et formant ainsi ly enlarged with a distinct area of induration noted on un kyste pelvien volumineux. Les symptômes du patient ont dis- the right posterolateral aspect of the gland. The serum paru. Une approche laparoscopique représente une excellente prostate-specific antigen level was 1.2 µg/L with a nega- option chirurgicale en présence de pathologie pelvienne. tive urine culture. Ultrasonography of the abdomen and pelvis revealed Introduction a solitary left kidney with compensatory hypertrophy. A large cystic structure measuring 8 × 5 cm, posterior to the A dysplastic kidney associated with a primary obstructed bladder and slightly off midline toward the right was iden- megaureter is an unsuspected finding during radiological tified (Fig. 1). The mass did not change after voiding and evaluation of adult patients with chronic, nonspecific pelvic did not appear to have direct communication with any discomfort. Renal dysplasia is a histological diagnosis made pelvic structure. by the presence of embryonic mesenchyme and primitive Computed tomography (CT) of the abdomen and pelvis renal components. Two types of dysplasia exist, one in which revealed a 7.9 × 7.2–cm mass posterior to the bladder, which CUAJ • April 2009 • Volume 3, Issue 2 159 © 2009 Canadian Urological Association Pianezza and Estey impressed on the posterior aspect of the bladder distal right ureter with resultant congenital absence (Fig. 2). The mass appeared to be above the of the right kidney due to obstruction. Also includ- prostate gland with no fat plane between the mass ed in the differential diagnosis were mullerian duct and prostate. The mass had 31 Hounsfield units, cyst, utrical cyst, seminal vesicle cyst or cystic neo- which suggested that it did not represent a sim- plasm of the prostate. ple cyst. Extending from the mass was an elongat- Owing to his persistent pelvic pain, the patient ed tubular structure that extended up the expect- elected for laparoscopic removal of the large ed course of the right ureter to the level of the renal pelvic cyst. An infrared fibreoptic ureteric stent vein, where it disappeared abruptly after tapering. was placed into the left ureter by cystoscopy On the delayed images no contrast was seen with- before starting the laparoscopic procedure. No in the mass or in the tubular structure (Fig. 3). The right ureteric orifice was identified by cystoscopy. left kidney was normal. The laparoscopic procedure involved the use of The differential diagnosis of the pelvic mass 4 ports (Fig. 4). The ports included an optical port based on radiological imaging included a dilated placed at the level of the umbilicus, two 5-mm ports placed on the left side between the anterior Fig. 1. Ultrasound of the abdomen and pelvis demonstrating a large cystic structure measuring 8 × 5 cm, posterior to the blad- der and slightly off the midline toward the right. Fig. 3. Computed tomography scan of the abdomen and pelvis with delayed images demonstrating no contrast within the mass or in the tubular structure. The left kidney excreted contrast nor- mally and the bladder filled with contrast. Fig. 2. Computed tomography scan of the abdomen and pelvis demonstrating a 7.9 × 7.2–cm mass posterior to the bladder, im- pressing on the posterior aspect of the bladder. Fig. 4. Diagram illustrating port placement used for this procedure. 160 CUAJ • April 2009 • Volume 3, Issue 2 Laparascopic removal of a pelvic cyst superior iliac spine and the umbilicus, and one a particular gene or genetic pathway malfunctions. 12-mm port placed on the right side between Common histological features of dysplastic kid- the anterior superior iliac spine and the umbili- neys include distortion of renal architecture, imma- cus. During the procedure a large cystic structure ture or primitive glomeruli, nephron precursors was identified extending from the level of the right such as comma- and S-shaped bodies, and carti- common iliacs down to the pelvis. There appeared lage and tubules encircled by collars of fibro- to be some remnants of renal tissue with a renal muscular cells referred to as primitive ducts.4,5 artery and vein. The renal vessels were dissect- Primitive ducts are considered to be the hallmark ed and clipped. The specimen was then dissect- finding of all dysplasia.10 ed into the region of the pelvis where there Dysplastic kidneys most often occur in conjunc- appeared to be a large tortuous ureter. The ureter tion with ectopic ureteral orifices, with the extent was attached to a very large pelvic cyst occupy- of dysplasia correlating with the degree of ectopia. ing the entire retrovesical space. The large cyst However, dysplastic kidneys may be seen in a few was dissected circumferentially with care taken patients with normal ureteral orifices. In such to preserve the left ureter. The seminal vesicles cases, obstruction may or may not be present.1–3 and ampulla of vas deferens were identified bilat- Obstructive conditions associated with renal dys- erally as normal and left in situ. The large cyst plasia include primary obstructive megaureter and also appeared to attach to the posterior aspect ureteropelvic junction obstruction. These condi- of the bladder wall. A small opening was made tions are usually associated with normally situat- in the bladder. An opening was also made in the ed ureteral orifices and kidneys that have suffered cyst wall and about 200 mL of fluid was drained. diffuse damage because of hydronephrosis.4,5 The cyst was excised and the portion on the pos- Laparoscopic nephrectomy and nephroureterec- terior aspect of the bladder wall was fully cauter- tomy for dysplastic kidneys are now becoming ized. A ureteral orifice was not identified. The widely accepted procedures for the pediatric pop- bladder defect was then closed laparoscopically ulation.6–9 Laparoscopic surgery can reliably con- in 2 layers with 2.0 Vicryl (Ethicon). The fibre- firm the diagnosis, locate the dysplastic kidney and optic stent was removed. ectopic ureter, and allow their removal simulta- Pathological assessment revealed mesonephric neously, safely and effectively. In addition, the remnants representing dysplastic renal tissue laparoscopic approach has allowed a reduction in attached to a cystically dilated and obstructed right patient morbidity, hospital stay and analgesia ureter, extending into the bladder wall and form- requirement. ing a large pelvic cyst. No definite glomeruli, prox- Laparoscopic removal of dysplastic kidneys in imal or distal tubules were seen. No malignancy the adult population is uncommon. Several cases was present. involving laparoscopic removal of dysplastic kid- The patient was discharged home on the sec- neys are reported in the literature. Buogo and col- ond postoperative day. He reported a substantial leagues11 reported a case of a 23-year-old man who reduction in his pelvic pain before discharge. At underwent laparoscopic removal of a symptomatic last follow-up, the patient was 7 months post- seminal vesicle cyst associated with an ectopic surgery with negative results on CT, and no longer ureter and dysplastic renal remnant.