Endometriosis of the urinary tract: symptoms, diagnosis, and treatment

Bladder endometriosis

Many authors have reported many cases of endometriosis of the bladder [1, 2, 3, 4, 5, 6, 7, 8, 9], with a particularly complete review of the literature after 1945 by Abeshouse [10]. Early reports frequently described the lesion as an adenomyoma of the bladder to reflect the histopathology seen under the microscope, with endometrial-like glands and stroma imbedded in fibromuscular metaplasia. Essentially, all reported cases represent spontaneous occurrence, and invasive bladder disease frequently coexists with significant invasive disease of the posterior pelvis. A case of full-thickness bladder endometriosis after Cesarean section has been reported [11], although there was no intraoperative bladder injury.


Bladder endometriosis may be superficial or deep. Superficial endometriosis of the peritoneum overlying the bladder is common and is usually asymptomatic. It is important to remember that just as with any other area of involvement in the body, invasive endometriosis can masquerade as a 'superficial' lesion unless discrimination is made by palpation or surgical resection.

Endometriosis invading the muscularis of the bladder is uncommon, and disease involving the mucosa is extremely rare. Invasive lesions are composed of combinations of endometrial-like glands and stroma surrounded by fibromuscular metaplasia. For this reason, such lesions have been termed 'adenomyomas' of the bladder [12]. With invasion of the muscularis, endometriosis of the bladder may result in urgency, frequency, nocturia [13], painful bladder spasm during voiding or either gross or microscopic hematuria [14]. These symptoms may be cyclic and increase during menses, although some patients may have a lower level of symptoms throughout the month. Interstitial cystitis should be considered in the differential diagnosis.


Cystoscopy will infrequently be helpful in the diagnosis of bladder endometriosis because full-thickness penetration of the bladder wall is rare. Occasionally, cystoscopy may reveal a bluish tinge beneath the mucosa, but a negative cystoscopy does not rule out significant invasion of the muscularis. A case of bladder endometriosis associated with a 14 week sized fibroid uterus was associated with decreased bladder capacity and increased detrusor irritability. These abnormalities resolved after hysterectomy and removal of a small 4 mm endometriotic nodule of the bladder [13]. The relative contribution of the enlarged uterus to this clinical picture confounds the issue of which problem caused the symptoms.

As with most cases of endometriosis, surgery provides the most accurate diagnosis. While magnetic resonance imaging (MRI) scans are recommended by some, scans do not relieve symptoms nor eliminate the eventual need for surgical exploration if symptoms do not resolve with conservative therapy. Additionally, the depth of resection required will be obvious at surgery since the surgical dissection will occur in normal soft tissue adjacent to a firmer nodule of bladder disease. Thus, preoperative scans will not assist the surgeon in planning or executing surgery. Just because a type of scan is available does not make it always necessary, particularly with a disease like endometriosis, which depends so heavily on surgery for diagnosis and treatment.


The principles of surgical diagnosis are identical whether performed at laparotomy or laparoscopy. Occasionally, peritoneal rolling will be seen across the uterovesical peritoneal fold (Fig. 1), and this frequently predicts only slight muscularis involvement. Invasive bladder disease that may result in full-thickness bladder resection can manifest as significant scarring and retraction of the bladder peritoneum with underlying nodularity and massive overlying hemorrhagic and exophytic changes (Fig. 2). Occasionally, a nodule of invasive bladder endometriosis may appear to be only a superficial hemorrhagic change (Fig. 3), with the nodule visible if the surface of the bladder is retracted (Fig. 4), or palpated, or if the bladder is filled with fluid instilled through a catheter.

Figure 1.

The peritoneum of the bladder exhibits rolling along its junction with the uterus, indicating significant endometriosis along this area, although bladder invasion is unlikely.

Figure 2.

Florid invasive and exophytic endometriosis with massive distortion of the position of the round ligaments. Bladder invasion will always be present with disease having this appearance

Figure 3.

An innocuous-appearing lesion of the right bladder. This appears to be a superficial hemorrhagic lesion. Actually, it is a large invasive bladder nodule which will require full-thickness resection of the bladder.

Figure 4.

Traction on the innocuous lesion seen in Fig. 3 reveals an underlying large nodule over 2cm in diameter.

Surgical treatment

The surgical treatment of bladder endometriosis by laparotomy or laparoscopy is essentially identical. Laparoscopic surgery on the bladder is easy and represents a good starting point for surgeons seeking to advance their skills. The bladder is easy to visualize and reach with laparoscopic instruments and is filled with a sterile fluid which keeps the risk of infection low. The surgeon must be able to perform intracorporeal suturing in some fashion to repair the bladder. The main risk in the surgical treatment of bladder endometriosis is possible damage to the portion of the ureter traveling within the bladder muscularis. Most cases of invasive endometriosis of the bladder do not encroach directly on the course of the ureter through the bladder muscularis or on the ureteral orifice.

Superficial endometriosis of the bladder peritoneum is easily treated by peritoneal resection without damage to the muscularis. Invasive bladder endometriosis will require partial-thickness resection of the muscularis or occasionally full-thickness resection resulting in partial cystectomy of the urinary bladder. This can usually be accomplished laparoscopically. Partial-thickness resections of bladder muscularis are reinforced with imbricating dissolving sutures which can be placed in running or interrupted fashion. If the sutures are placed with care within the outer layer of muscularis which has been damaged, there is little risk to the unseen ureters. Ureteral catheters are rarely helpful and are not mandatory.

Nodules of the bladder wall are approached first by dissecting into normal, soft bladder muscularis adjacent to the nodule (Fig. 5). The nodule is circumscribed and undermined by incising normal muscularis (Fig. 6), until it is removed entirely either by partial-thickness or full-thickness resection.

Figure 5.

Electrosurgical incisions are created around the nodule in normal bladder muscularis.

Figure 6.

Full-thickness penetration of the bladder has just occurred.

Even a large diameter full-thickness penetration of the bladder during surgery may not always be apparent to the surgeon (Figs 7 & 8). Sometimes, the first notice of bladder penetration will be when the retention catheter bag is noted to fill with air, although neither this nor hematuria is always present during surgery [15]. Resection of large nodules will result in obvious entry into the bladder (Fig. 7). The ureteral orifices may sometimes be slightly hidden behind the rim of the posterior bladder wall, which needs to be retracted in order to view the jets of urine exiting the ureters (Fig. 9). Intravenous injection of indigo carmine may help identify the orifices more easily. It is mandatory to identify the ureteral orifices upon initial bladder entry to judge if the ensuing dissection may encroach upon them. The surgeon needs to be aware of the course of the unseen portion of the ureter within the bladder muscularis traveling posterolaterally away from the visible orifice. Since bladder endometriosis rarely involves the inferior wall of the bladder adjacent to the ureters and trigone, in most cases it is easy to repair the bladder in two layers without high risk of damage to the ureters. The mucosa can be repaired with absorbable suture, such as running 3-0 Vicryl (Fig. 10), while the muscularis is repaired with running 1-0 or 2-0 Vicryl. Interrupted sutures can also be used to repair the bladder, although this may take slightly longer. Once the bladder has been repaired, its integrity can be checked with instillation of irrigation fluid, with or without colored dye, injected through the catheter, although a retention catheter left in place postoperatively can allow even a poorly repaired bladder to heal. If the repair is perfectly watertight, the retention catheter can be removed when the patient is mobile, otherwise it should be left in for at least a week. If a surgeon may think it risky to remove the catheter soon after surgery, it should be kept in mind that suture repair of full-thickness bowel resections heal without any catheter bowel drainage or diversion. If the surgeon is concerned about possible constriction of the ureter by a stitch, cystoscopy can be done to observe bilateral ureteral patency as shown by passage of indigo carmine. In rare instances, it may be preferable to pass ureteral catheters or to perform an intraoperative retrograde pyelogram to document ureteral patency.

Figure 7.

After resection of the nodule, a large bladder defect is obvious if the anterior edge of the defect is retracted anteriorly.

Figure 8.

The large defect seen in Fig. 7 is virtually inapparent without traction on the bladder.

Figure 9.

The left ureteral orifice is seen in the center of the frame, appearing like an oval crater on top of a hillock.

Figure 10.

The bladder is repaired in two layers. Here, the mucosal closure with running 3-0 Vicryl is begun. The seromuscular layer is closed over this in running fashion with 3-0 Vicryl or similar suture.

One case of endometriosis involving the entire trigone has been encountered. This patient had multiple painful nodules palpable through the anterior vaginal wall, as well as associated severe pelvic disease with obliteration of the cul-de-sac. At laparotomy, it was necessary to remove the entire trigone from the level of the ureteral orifices down to the internal urethral meatus. The ureteral orifices were immediately adjacent to but not involved by the disease process and closure of the bladder left one ureter immediately anterior to the other, in an 'over and under' configuration. The patient had normal bladder function after removal of the catheter one week after surgery.

Laparoscopic resection of full-thickness bladder nodules has become fairly routine in many endometriosis treatment centers [16], and is associated with a low morbidity rate.

Ureteral endometriosis

Ureteral endometriosis is less common than invasive endometriosis of the bladder and has been reported by many authors [17, 18, 19, 20, 21].

Endometriosis invading the ureter is very rare and always results from extension of locally invasive disease from an adjacent uterosacral ligament nodule. More frequently, the ureter itself is not invaded by endometriosis, but is encircled by constrictive fibrosis related to invasive disease of the adjacent uterosacral ligament. When the diameter of the ureter is compromised either by extrinsic compressive fibrosis or actual invasion of the muscular wall of the ureter by endometriosis, hydroureter and hydronephrosis can occur with resultant flank pain which may occur or worsen during menses. In some cases, the stricture tightens so slowly that complete loss of kidney function occurs silently, sometimes with associated hypertension [21].

Preoperative intravenous pyelogram, spiral computed tomography (CT) scan, renal scan, or intraoperative retrograde pyelogram may all be helpful in defining the extent of damage to the ureter and to renal function. For example, if the diameter of the ureter is seen to be small or non-existent, then resection of the involved portion of the ureter may be anticipated. In such a case, a urologist can assist by passing ureteral stents at the proper time during surgery. If renal function is already compromised or lost, this is helpful to know for medical and legal purposes so that unjust blame will not be assigned to surgical injury. If complete loss of kidney function seems apparent, laparoscopic nephrectomy may be a consideration.

Surgical treatment of endometriosis by removal of something else is rarely good practice, although this is favored by inexperienced surgeons. Thus, attempting to 'treat' ureteral obstruction by removal of the pelvic organs will frequently result in postoperative incredulity by the patient that her disease was left untouched and may invite further surgery since the obstructing nodule was left in place. Even in the absence of ovaries, invasive endometriosis may remain symptomatic because of the conversion of adrenal precursors into estrogen by the action of aromatase enzyme produced by the nodule itself.

Patients with ureteral obstruction due to endometriosis who have been treated by removal of the pelvic organs and retention of endometriosis may have involvement of the vaginal apex by disease invading from the underlying involved uterosacral ligament (Fig. 11). Surgery commences vaginally by circumscribing the lesion with electrosurgery until the soft areolar tissue of the rectovaginal septum is encountered (Fig. 12). This will make the last part of the upcoming laparoscopic surgery easier. The initial laparoscopic view (Fig. 13) will frequently seem normal, since all the invasive disease is retroperitoneal and bowel and omentum may be adherent to the pelvic surfaces, especially in the area overlying the active retroperitoneal nodule (Fig. 14).

Figure 11.

This patient had previous hysterectomy and castration. The apex of the vagina is involved by endometriosis invading from the region of the right uterosacral ligament, which in turn involved the ureter in retroperitoneal fibrosis.

Figure 12.

The vaginal lesion seen in Fig. 11 is circumscribed, the incision entering only into the rectovaginal septum.

Figure 13.

The laparoscopic view of the case seen in Figs 11 and 12 seems to be normal.

Figure 14.

The ileum is adherent to the right uterosacral ligament. Note the right hydroureter in the bottom center of the frame, adjacent to the hemorrhagic area.

Retroperitoneal fibrosis accompanying endometriosis may surround the ureter, requiring tedious ureterolysis. Frequently, this fibrosis will contain glands and stroma of endometriosis (Fig. 15), although sometimes the fibrosis seems to be only an intense reaction to adjacent disease. Ureterolysis is begun high on the pelvic sidewall in normal peritoneum anterior or posterior to the ureter. If an ovarian endometrioma cyst is adherent to the sidewall over a ureter, the retroperitoneal fibrosis can be surprisingly intense (Fig. 16) and the ovary will need to be freed and suspended from the adjacent round ligament with 4-0 Vicryl so it will not impede visualization during an already difficult dissection. Sharp and blunt dissection combined with occasional cutting with short bursts of electro-surgery or laser will allow the ureter to be progressively freed up. A vessel loop may be helpful for ureteral traction (Fig. 17), although more commonly an atraumatic grasper can be used to pull the ureter strongly in one direction or another in order to obtain a line of attack against the fibrosis. Sometimes, the fibrosis will be isolated to an area immediately lateral to the uterosacral ligament, and probing the ureteral tunnel under the uterine artery will show that the ureter is freely mobile within this tunnel, in which case further ureterolysis toward the bladder is unnecessary. It will sometimes be necessary to sacrifice branches of the internal iliac artery, most commonly the uterine artery (Figs 18 & 19), in order to completely free the ureter, and these can be controlled either with monopolar or bipolar coagulation or with sutures. Ureterolysis will be necessary immediately against the muscular wall of the ureter and occasionally small bleeding vessels on the surface of the ureter may require control by careful electrocoagulation applied in a very brief burst using a small active electrode. Bipolar electrocoagulation around the ureter may be problematic since many coagulator paddles are too large to apply a small energy footprint, so the risk to the ureter may be increased. Periureteral fibrosis may involve up to 4cm of the length of the ureter and may extend down to the edge of the base of the bladder. When the uterus is in place, the uterosacral ligament nodules will need to be amputated from the uterus while still encircling the ureters (Fig. 20).

Figure 15.

Periureteral fibrosis often harbors endometriosis. The adventitia of the ureter on the left upper side of the frame contains endometriosis. The muscular wall of the ureter is in the right lower side of the frame.

Figure 16.

The left ovary is seen in the upper left corner of the frame, just beneath the shaft of the graspers. It is densely adherent to the left broad ligament. Dense retroperitoneal fibrosis has entrapped the ureter which is being placed on stretch by the 3 mm scissors.

Figure 17.

A vessel loop can sometimes be helpful in gentle traction on the ureter.

Figure 18.

The right uterine artery is densely adherent to the right ureter lateral to the right uterosacral ligament. The artery has been ligated prior to transection.

Figure 19.

After transection, the right ureter is more visible and the distal uterine artery can now be dissected away from the ureter, thus completing the ureterolysis.

Figure 20.

The right ureter is involved by dense fibrosis associated with endometriosis. The mass being grasped consists of endometriosis as well as the lateral side of the cervix and right uterosacral ligament.

In rare cases, the muscularis of the ureter will be invaded by endometriosis which may penetrate to the lumen with resultant partial or complete occlusion (Fig. 21). In such a case, resection of a portion of the wall of the ureter is necessary. The dissection to free up the ureter is much more difficult than the resection of the ureter and its repair. The dissection should seek to find fatty tissue deep to the ureter on its anterior, lateral and posterior sides (Fig. 22). When the nodule is put on traction, retroperitoneal areolar tissue will exhibit straight lines of tissue pleats which will converge on the nodule (Fig.23). These straight tissue pleats can be severed without undue risk to the ureter. However, as the nodule is approached, the fibrosis will encircle the ureter tightly and it will be necessary to operate directly on the ureter (Fig. 24). The nodule must be completely separated from the ureter (Fig. 25).

Figure 21.

This is the case seen in Fig. 20. The endometriosis to the left side of the frame has invaded the wall of the ureter. The epithelial lining of the ureter is seen in the lower right of the frame. The left ureter was involved by an identical process.

Figure 22.

In this patient with previous hysterectomy and removal of the ovaries, the right ureter is in the bottom center of the frame and is massively dilated. Retroperitoneal dissection has begun to isolate a mass involving the stump of the right uterosacral ligament.

Figure 23.

The right uterosacral ligament mass is separated from the right side of the rectum.

Figure 24.

The ureter has been almost completely freed from the right uterosacral ligament mass posteriorly and laterally. The tight fibrosis associated with the mass had produced an area of severe ureteral constriction.

Figure 25.

The last medial attachment of the mass to the ureter is severed.

Ureterolysis should extend at least 1cm in each direction beyond the segment to be removed so that normal distal ureter is visible and available for suture. The segment to be resected will be apparent as a strictured area (Fig. 26) which may have a gristly texture when brushed with an atraumatic grasper. The ureter proximal to the stricture may be obviously dilated while the distal ureter will appear normal in diameter (Fig. 27). Intravenous indigo carmine should be given before the segmental resection of the ureter is begun. The urologist should be present and performing cystoscopy with a double-J ureteral stent ready for passage in a timely manner. The ureter is cut proximal to the stricture with electrosurgical cutting current, cold scissors, or laser. The immediate exit of indigo carmine dye will give reassurance that no obstructive lesion has been left behind in the proximal segment. The cut edge of the proximal ureter can be inspected and should have a consistent thickness circumferentially since invasion of the wall of the ureter by endometriosis would be manifest by a thicker area. The diameter of the cut to the proximal ureter will be larger than normal and the wall may appear to be slightly thinned. The strictured area is now grasped and put on traction superiorly and the ureter is transected distal to the stricture. Sometimes, it will be necessary to trim the distal ureter further to ensure removal of all endometriosis. Since the resected segment typically measures less than 1.5cm in length, primary anastomosis is usually possible. The urologist now passes a guidewire through the distal stump of the ureter and the gynecological surgeon grasps the wire and feeds it into the proximal stump (Fig. 28). The stent is advanced over the guidewire (Fig. 29) and intraoperative fluoroscopy is done to prove proper placement. The urologist is now free to leave the operating room after as little as 10 or 15 minutes of work. The ureter is reunited with four or five sutures of 4-0 Vicryl applied in each quadrant (Fig. 30). The first stitch usually accomplishes a rough approximation which can be reinforced properly with other stitches. The ends of sutures which have already been applied should be kept somewhat long so they can be grasped to help rotate the ureter in order to apply subsequent stitches. The stitch can pass through just the muscularis or can pass through the mucosa as the surgeon wishes. It has not been necessary to spatulate the distal stump to accommodate the larger diameter of the proximal stump. The stent is removed in the urologist's office after six weeks.

Figure 26.

The strictured segment of the ureter is being excised. The scissors are cutting across normal distal ureter.

Figure 27.

The graspers are holding the proximal edge of the strictured segment. An incision has begun across the proximal normal ureter.

Figure 28.

After removal of the stricture segment, a guidewire is passed by cystoscopy through the right ureter and is being delivered into the proximal segment of ureter by the graspers.

Figure 29.

The double-J stent is passed over the guidewire before suturing the ureter.

Figure 30.

Four quadrant sutures of 4-0 Vicryl have been placed to complete the ureteral anastomosis.

Bypass of the ureteral obstruction by redirection of the ureter via a psoas hitch may not be good practice. While this will relieve ureteral obstruction, the uterosacral ligament nodule responsible for the ureteral obstruction remains highly symptomatic for non-urologic reasons and will require reoperation. In one woman with previous left nephrectomy because of left ureteral obstruction by endometriosis, the right ureter was bypassed around the obstructing right uterosacral ligament nodule. The bypassing right ureter was reinvaded and was almost completely obstructed anew by the nodule that had not been removed.

Renal endometriosis

Endometriosis of the kidney is very rare and may cause back pain or hematuria which does not always occur with menses. Some cases can be asymptomatic and discovered incidentally at autopsy. Some symptomatic cases have been diagnosed by nephrectomy [22, 23].

A 40-year-old woman had a 10 month history of left flank pain and swelling and a painless mass in the left upper quadrant. There was no change of the pain or the mass with menses. The urinalysis showed minimal proteinuria but no red blood cells. Intravenous pyelogram showed a marked abnormality of the left kidney. At nephrectomy, the middle of the left kidney was replaced by a 9cm cystic mass which was partially filled with chocolate-colored fluid. Smaller cysts were present within this mass which were filled with clear fluid. The mass was found to contain glands and stroma typical for endometriosis [23].

One patient with daily hematuria and back pain was found by a combination of angiography and ultrasonography to have a 4cm cystic lesion of the left kidney [24]. Needle biopsy of the lesion showed glandular fragments and cuboidal epithelium which could not have been of renal origin. At laparoscopy, a 1.5cm endometrioma cyst was removed from the left ovary but no other endometriosis was seen. Symptomatic treatment with progestins for 6 months was only partially successful and repeat laparoscopy showed three sites of pelvic endometriosis, each only 1mm in dimension. Nafarelin given by daily nasal inhalation for 11 months caused cessation of back pain and hematuria within one month and reduction of the left renal cystic lesion to 2cm with only red and white blood cells found on repeat needle biopsy. Five months after cessation of nafarelin therapy, symptoms recurred and cystoscopy showed blood coming from the right ureteral orifice. Nafarelin was resumed for 8 months and the patient remained symptom-free for at least 41 months following treatment.


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