Transitional cell carcinoma arising in the gastric remnant following gastrocystoplasty: a case report and review of the literature

Invasive poorly differentiated adenocarcinoma of the bladder following augmentation cystoplasty: a multi-institutional clinicopathological study

Augmentation cystoplasty is a surgical procedure used in the management of patients with neurogenic bladder. This procedure involves anastomosis of the bladder with gastrointestinal grafts, including portions of ileum, colon, or stomach. A rare but important complication of augmentation cystoplasty is the development of malignancy. The majority of malignancies arising in this setting have been described in case reports. A search for cases of non-urothelial carcinoma following augmentation cystoplasty was conducted through the urological pathology files of four major academic institutions. Ten cases were identified, including six cystoprostatectomy/cystectomy, two partial cystectomy, and two transurethral resection of bladder tumour specimens. The mean patient age at diagnosis was 47 years (range 27-87 years). The male:female ratio was 4:6. The tumours tended to present at an advanced stage; four cystoprostatectomy/cystectomy cases were categorised as pT3a, one was categorised as pT3b, and one was categorised as pT4a. Lymph node metastases were present in all cases which had lymph node excision (range 1-16 positive nodes per case). The majority of cases (90%) were predominantly characterised by a poorly differentiated adenocarcinoma with signet ring cell features. Other morphological features included mucinous features (30%), plasmacytoid features (20%), enteric/villous architecture (10%), and large cell undifferentiated morphology (10%). This is the largest study to date on the clinicopathological features of invasive non-urothelial carcinoma of the bladder following augmentation cystoplasty. The tumours are typically poorly differentiated adenocarcinoma, with diffuse signet ring cell features, aggressive, and present at high stage. Further molecular characterisation may provide additional insights into the pathogenesis of this entity.

Bladder Augmentation (Enterocystoplasty): the Current State of a Historic Operation

PURPOSE OF REVIEW

The goal of this paper was to evaluate the current use of enterocystoplasty, a historical operation for bladder dysfunction but with continued and increasing modern relevance.

RECENT FINDINGS

Since the advent of third line neuromodulation techniques for neurogenic and idiopathic overactive bladder (OAB), the usage of enterocystoplasty has decreased. However, this procedure continues to be utilized in pediatric urology patients and the most refractory OAB patients. Adult urologist should be familiar with this operative technique in an effort to manage pediatric patients transitioning to adulthood. Minimally invasive techniques for this surgical procedure have been described with very limited outcome data. It is important for all urologists to be familiar with enterocystoplasty, both technically and with the unique needs of these patients postoperatively. Further studies evaluating the outcomes of this procedure in idiopathic overactive bladder patients and efforts to standardize recommendations for neurogenic bladder patients will help guide care in the future.

Secondary Tumors After Urinary Diversion

It has been known that urinary diversions juxtaposing the urinary and intestinal tracts lead to increased incidence of secondary malignancies. Although tumorigenesis in ureterosigmoidostomies follows the typical course from adenomas to adenocarcinomas, secondary malignancies arising from isolated intestinal diversions are much more heterogeneous. Research over the last half century has unveiled patterns of incidence and progression, while also uncovering possible mechanisms driving the neoplastic changes. In this review, we summarize the current understanding of these unique tumors, with the hope that the knowledge gained may shed light on the etiologies of other cancers arising from the urinary and intestinal tracts.

Systematic review of bladder cancer outcomes in patients with spina bifida

BACKGROUND

In patients with congenital bladder anomalies, bladder augmentation is used as a last resort to reduce intravesical pressure, but concerns about malignant transformation in augmented patients were first raised in the 1980s. The best evidence to date indicates that augmentation does not appear to increase the risk of bladder cancer in spina bifida patients. To date, oncologic outcomes from patients with spina bifida with and without augmentation have only been available in small case reports.

OBJECTIVE

To systematically evaluate factors in myelomeningocele patients with bladder cancer, including bladder augmentation, that contribute to overall survival (OS).

STUDY DESIGN

A systematic review using PubMed was conducted by cross referencing terms 'myelomeningocele,' 'cystoplasty,' 'bladder cancer' and respective synonyms according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Inclusion criteria were studies with patients with an underlying diagnosis of myelomeningocele and bladder cancer with data on age, stage, and mortality status. Studies were excluded for spinal cord injury, history of tuberculosis or schistosomiasis, or prior ureterosigmoidostomy.

RESULTS

Fifty-two patients were identified from 28 studies with a median age at bladder cancer diagnosis of 41 years (range 13-73); 37 (71%) presented with stage III or IV bladder cancer. Overall survival at 1 year and 2 years was 48.5% and 31.5%, respectively. Overall survival was different between those with and without augmentation (P = 0.009) by log-rank analysis. No between-group differences in OS were seen based on age, management with indwelling catheter, diversion with ileal conduit or being on a surveillance program. Only stage remained a significant predictor of OS on multivariate analysis (HR 2.011, 95% CI 1.063-3.804, P = 0.032). Secondary analysis was performed after removing patients with gastric augmentation (n = 8), and no difference in OS was seen between patients with (n = 8) and without augmentation (n = 36, P = 0.112). Of augmented patients, latency to development of bladder cancer was variable (Summary Figure).

DISCUSSION

Bladder cancer is a deadly diagnosis in patients with congenital bladder anomalies like spina bifida, and while overall prevalence of the two conditions occurring together is low, bladder cancer will go on to affect 2-4% of spina bifida patients. The present study examined overall survival, and further characterized outcomes in these patients. Presence of a bladder augment did not appear to worsen overall survival.

CONCLUSIONS

Patients with myelomeningocele who developed bladder cancer had aggressive disease. Augmentation did not worsen OS, based on cases reported in the literature. Risk of bladder cancer should be discussed with all myelomeningocele patients.

Management of bleeding-associated severe gastritis of the gastric mucosa in a patient with a gastrocystoplasty

Gastrocystoplasty is a form of bladder augmentation (neobladder), where a segment of the stomach is surgically attached to the urinary bladder to increase bladder capacity and compliance. Although bleeding and malignant complications of gastrocystoplasty have been reported, the risks of these complications in the setting of gastrocystoplasty are not known. We describe the case of a 58-year-old African American woman with a history of a congenital solitary kidney, chronic kidney disease, and status postgastrocystoplasty and catheterizable umbilical stoma 21 years ago for neurogenic bladder presented with gross hematuria. To the best of our knowledge, this is the first reported case of gastrocystoplasty with a bleeding complication that has endoscopic pictures before and after treatment with proton pump inhibitor.

The evolution of bladder augmentation: from creating a reservoir to reconstituting an organ

Bladder augmentation was first described in 1899. The goal at the time was to establish the ideal method to create a simple capacious reservoir for the safe storage of urine. That simple idea has over the last 100 years grown into one of the most dynamic areas in Pediatric Urology. Creative minds and hands from individuals in multiple disciplines have led us from creating a reservoir to the threshold of recreating a functional organ. In this review, we look at the historical evolution of bladder augmentation and how it exponentially grew in scope from those initial descriptions of intestinocystoplasty to the work being reported today in the field of tissue engineering.

Understanding roles of porcine small intestinal submucosa in urinary bladder regeneration: identification of variable regenerative characteristics of small intestinal submucosa

Neuropathic bladders are the result from damages to the central or peripheral nervous system, and ultimately may require surgical reconstruction to increase bladder volumes and to reduce the risk of damages to the kidneys. Surgical reconstruction through bladder augmentation has traditionally been practiced using a segment of the ileum, colon, or stomach from the patient through enterocystoplasty. However, the use of gastrointestinal segments can lead to serious adverse consequences. Porcine small intestinal submucosa (SIS), a xenogeneic, acellular, biocompatable, biodegradable, and collagen-based bioscaffold is best known to encourage bladder regeneration without ex vivo cell seeding before implantation in various experimental and preclinical animal models. Although it has been demonstrated that SIS supports bladder cell growth in vitro, and SIS-regenerated bladders are histologically and functionally indistinguishable from normal functional tissues, clinical utilization of SIS for bladder augmentation has been hampered by inconsistent preclinical results. Several variables in SIS, such as the age of pigs, the region of the small intestine, and method of sterilization, can have different physical properties, biochemical characteristics, inflammatory cell infiltration, and regenerative capacity due to cellular responses in vitro and in vivo. These parameters are particularly important for bladder regeneration due to its specific biological function in urine storage. Clinical application of SIS for surgical bladder reconstruction may require graft materials to be prepared from a specific region of the small intestine, or to be further formulated or processed to provide uniform physical and biochemical properties for consistent, complete, and functional bladder regeneration.

Full-thickness hysterocystoplasty for management of a large bladder defect: experimental study in goats

The uterine tissue of three healthy nonpregnant goats was evaluated experimentally as a graft for closure of a bladder defect. Goats were subjected to ovariectomy, and then one detubularized uterine horn was used as a graft to close a large defect in the ventral aspect of the bladder. Follow up included monthly radiographic and ultrasonographic examinations and evaluations of kidney function and electrolytes changes for six months. The goats were euthanized after six months, and both the bladder and the graft were examined macroscopically and histologically. The technique required less invasive procedures than those described with alternative techniques of cystoplasty, achieved a high survival rate without life-threatening complications post surgery, was associated with no significant changes in kidney function and electrolytes levels, showed proper healing of the transplanted graft by regeneration rather than repair without scaring or fibrosis and with complete covering of the graft by a healthy urothelium and was associated with no malignant transformation. Hysterocystoplasty is a non-invasive, non-life-threatening technique due to the close position of the bladder to the uterus, and proper healing of the graft reflects absence of pressure on its blood supply. It is an acceptable alternative technique for closure of a large bladder defect and avoids disadvantages of alternative techniques of cystoplasty. It might be accepted by owners of pets, and further studies in clinical cases of dogs are advised.

[Metabolic long-term complications after urinary diversion]

Metabolic long-term complications and consequences after urinary diversion are somewhat neglected. Subclinical metabolic disturbances are quite common; however, complications are rare. The absorptive surface of the bowel segment is lost for the physiological function of the gastrointestinal tract. Some studies demonstrated that at least some of the absorbent and secreting properties of the bowel are preserved if exposed to urine. For each bowel segment typical complications are reported. Using ileal and/or colon segments, hyperchloremic metabolic acidosis may occur. Studies demonstrated that metabolic effects are not as severe as suspected and could be prevented if a prophylactic treatment is started early.The resection of ileal segments is responsible for malabsorption of vitamin B(12) and bile acid; when using colonic segments, electrolyte disturbances are more common. Careful patient selection, meticulous follow-up and prophylactic treatment are crucial to prevent metabolic complications.

Experimental gastrocystoplasty in rats: risk of developing ECLoma

OBJECTIVE

There are no clinical reports on the risk of carcinoids in the gastric segment following gastrocystoplasty. The aim of the present study was to examine whether gastric carcinoids could develop in a rat model of gastrocystoplasty.

MATERIALS AND METHODS

Rats were subjected to gastrocystoplasty in which 10% of the oxyntic part of the stomach was removed (i.e. 10% fundectomy), gastrocystoplasty with 90% fundectomy (known to induce hypergastrinemia), sham operation, or no operation, and were followed up for 6 months. Tissue specimens of bladder and stomach were analyzed by means of pathology and immunohistochemistry.

RESULTS

Atrophy of gastric glands in the augmented bladders was found after gastrocystoplasty with either 10% or 90% fundectomy. Gastrocystoplasty with 90% fundectomy resulted in hyperplasia of the oxyntic mucosa, enterochromaffin-like (ECL) cell hyperplasia and ECLoma in the remnant stomach, and atrophy of the oxyntic mucosa and ECLoma in the gastric segment of the bladder.

CONCLUSIONS

ECLoma could develop in the gastric segment of the bladder after gastrocystoplasty, particularly in the setting of hypergastrinemia. The tumorigenesis of ECLoma seems to follow the same pathological pathway regardless of whether the oxyntic mucosa is located in the stomach or the bladder.

Re-epithelialization of demucosalized stomach patch with tissue-engineered urothelial mucosa combined with Botox A in bladder augmentation

Re-epithelialization demucosa stomach patch is important to prevent the patch being exposed to urine that might cause patch shrinkage and fibrosis formation due to urine-derived chemical irritation. Additionally, Botox A acts by blocking the transmission of nerve impulses to smooth muscles and so paralysing the muscles, which is commonly used to relax muscle for treatment of oesophageal achalasia due to overactive smooth muscle and sphincters of gastrointestinal tract. We fabricated in vitro tissue engineered urothelial mucosa with multi-layers of urothelium and smooth muscle layers seeded on SIS scaffold and then used this cell-scaffold construct to cover nuke gastro patch combining with Botox A for gastrocystoplasty in a canine model.

OBJECTIVE

To evaluate the demucosalized stomach patch covered with tissue-engineered urothelium for gastrocystoplasty and to determine whether or not injections of Botox A into the re-epithelialized stomach patch can protect the graft from contraction in a canine bladder reconstruction model.

MATERIALS AND METHODS

Gastrocystoplasty was performed in 10 adult beagles after hemi-cystectomy using five types of stomach patch (n = 2 per group): entire stomach patches (group I); demucosalized patches (group II); demucosalized patches covered with cell-free small intestinal submucosa (SIS) (group III); demucosalized patches with urothelial and smooth muscle cell-seeded SIS (group IV); and demucosalized patches with the cell-seeded SIS combined with injections of Botox A (group V). The bladder volume/pressure and the graft sizes were measured before surgery and again 10 weeks after bladder augmentation. The graft tissues were examined both histologically and using immunohistochemistry.

RESULTS

All dogs survived and their gastric grafts were all vital with a good blood supply. Gastric metaplasia of urothelium appeared on the top of stomach mucosa patches in two animals in group I. There was calcification formation at the centre of the graft in one animal in group II. As compared with urothelium that was partially covered over with stomach patches in groups II and III, stratified urothelium completely covered the demucosalized gastric patches in groups IV and V. There was less shrinkage of the stomach grafts in groups I and V, which shrank to half of their original size, than of the stomach grafts in groups II, III, and IV, which shrank significantly to one-quarter of their original sizes.

CONCLUSIONS

Botox A injections appear to protect the graft contraction in the re-epithelialized stomach flaps. The gastrocystoplasty using demucosalized patches covered with tissue-engineered urothelial mucosa combined with an injection of Botox A could have clinical potential for use in bladder reconstruction.

The past, present and future of augmentation cystoplasty

What's known on the subject? And what does the study add? There is a wealth of evidence on the development, indications, outcomes and complications of augmentation cystoplasty (AC). Over the last decade, new evidence has been emerging to influence our clinical practice and application of this technique. AC is indicated as part of the treatment pathway for both neurogenic and idiopathic detrusor overactivity, usually where other interventions have failed or are inappropriate. The most commonly used technique remains augmentation with a detubularised patch of ileum (ileocystoplasty). Controversy persists over the role of routine surveillance following ileocystoplasty for the detection of subsequent bladder carcinoma; however the indication for surveillance after gastrocystoplasty is clearer due to a rising incidence of malignancy in this group. Despite a reduction in the overall numbers of AC operations being performed, it clearly still has a role to play, which we re-examine with contemporary studies from the last decade.

Malignancy after gastrointestinal augmentation in childhood

INTRODUCTION

To review the incidence and risks of bladder cancer following gastrointestinal augmentations done for congenial anomalies in childhood.

MATERIALS AND METHODS

A literature search using PubMed and Ovid Medline search engines was performed. MeSH terms evaluated were; bladder augmentations, enterocystoplasty, gastrocystoplasty, spina bifida, spinal dysraphism, myelodysplasia, neural tube defects, posterior urethral valves and bladder exstrophy were cross referenced with the terms, bladder cancer and urinary bladder neoplasm. All patients who developed a bladder cancer following a bladder augmentation for a congenital anomaly were reviewed.

RESULTS

A total of 20 cases of bladder cancer following augmentations for congential anomalies, were identified, 9 arose following ileal cystoplasty, 3 following colocystolasty and 8 following gastrocystoplasty. The incidence of cancer developing per decade following surgery was 1.5% for ileal/colonic and 2.8% for gastric bladder augmentations. The majority of cancers developing within the augmented bladder are at advanced stages at the time of diagnosis (60%; 12/20 cases were ≥T3 at diagnosis). Several of the cases that developed occurred in patients exposed to known carcinogenic stimuli and/or arose in bladders with a known predisposition to carcinoma.

CONCLUSION

Patients augmented with ileal or colonic segment for a congenital bladder anomaly have a 7-8 fold and gastric augments a 14-15 fold increased risk for the development of bladder cancer over standard norms. Published data is however unable to determine if gastrointestinal bladder augmentation is an independent risk factor for cancer over the inherent risk of cancer arising from a congenitally abnormal bladder.

Augmentation cystoplasty and risk of neoplasia: fact, fiction and controversy

PURPOSE

We determined if ileal/colonic bladder augmentation performed in patients with congenital bladder abnormalities is an independent risk factor for bladder malignancy.

MATERIALS AND METHODS

We reviewed a registry of patients with bladder dysfunction due to neurological abnormalities, exstrophy and posterior urethral valves. Individuals treated with augmentation cystoplasty were matched (1:1) to a control group treated with intermittent catheterization based on etiology of bladder dysfunction, gender and age (±2 years).

RESULTS

We evaluated 153 patients with an ileal/colonic cystoplasty and a matched control population. There was no difference (p=0.54) in the incidence of bladder cancer in patients with augmentation cystoplasty (7 patients [4.6%]) vs controls (4 [2.6%]). In addition, there was no difference between the 2 groups regarding age at diagnosis (51 vs 49.5 years, p>0.7), stage (3.4 vs 3.8, p>0.5), mortality rate (5 of 7 [71%] vs 4 of 4 [100%], p>0.4) or median survival (18 vs 17 months, p>0.8). Irrespective of augmentation status patients with a history of renal transplant on chronic immunosuppression had a significantly higher incidence of bladder cancer (3 of 20 [15%]), compared to patients who were not immunosuppressed (8 of 286 [2.8%], p=0.03).

CONCLUSIONS

In patients with congenital bladder dysfunction ileal/colonic bladder augmentation does not appear to increase the risk of bladder malignancy over the inherent cancer risk associated with the underlying congenital abnormality. In addition, immunosuppression irrespective of bladder treatment is an independent risk factor for malignancy in this patient population.

Bladder adenocarcinoma following gastrocystoplasty

Bladder augmentation with segments of small bowel (ileocystoplasty), large intestine (colocystoplasty) or stomach (gastrocystoplasty) has been used to treat patients with small or noncompliant bladders by increasing the capacity or compliance. Carcinomas following gastrocystoplasty have been observed in the segments of stomach; however, to our knowledge, carcinoma arising in the residual native bladder has not been reported. We report the first case of adenocarcinoma arising in the residual native bladder in association with intestinal metaplasia and dysplasia of bladder mucosa 17 years following gastrocystoplasty. Intestinal metaplasia secondary to recurrent urinary infection, chronic inflammation, and some form of irritation may potentiate the development of native bladder adenocarcinoma. Patients with gastrocystoplasty are at an increased risk for carcinoma in stomach segments and require close long-term follow up; however, the risk of carcinoma in native bladder is still unclear.

Tumor in Bladder Reservoir After Gastrocystoplasty

PURPOSE

To our knowledge the risk of malignancy in patients with previous bladder augmentation with stomach is unknown. We report 3 cases of gastric adenocarcinoma and 1 of transitional cell carcinoma after augmentation cystoplasty with stomach with long-term followup.

MATERIALS AND METHODS

Between August 1989 and August 2002, 119 patients underwent augmentation cystoplasty with stomach at our 2 institutions (University of Miami School of Medicine, and Seattle Children's Hospital and Regional Medical Center). Medical records, urodynamic studies, radiographic imaging and laboratory evaluations were reviewed retrospectively and cases of malignancy were analyzed in detail.

RESULTS

Four male patients had carcinoma after augmentation gastrocystoplasty. Preoperative diagnosis was neurogenic bladder in 3 patients and posterior urethral valve in 1. Three patients had gastric adenocarcinoma, while the other had poorly differentiated transitional cell carcinoma. Each case progressed to malignancy more than 10 years after augmentation (11, 12, 14 and 14 years, respectively).

CONCLUSIONS

Patients who undergo bladder augmentation with a gastric remnant are at increased risk for malignancy, probably similar to that in patients with enterocystoplasty. Therefore, they require close long-term followup. Patients should be followed annually with ultrasound, and cystoscopy should be performed annually starting 10 years after gastrocystoplasty unless they have abnormal ultrasound, hematuria or another cancer risk factor. Any suspicious lesions should be biopsied, especially at the gastrovesical anastomotic site.

Patients With Spina Bifida and Bladder Cancer: Atypical Presentation, Advanced Stage and Poor Survival

PURPOSE

Patients with neurogenic bladder dysfunction due to spina bifida have been reported to be at increased risk for bladder cancer. Recent publications suggest that bladder augmentation is also a significant risk factor. We reviewed our experience with treating patients with spina bifida and bladder cancer.

MATERIALS AND METHODS

Patients with spina bifida treated for bladder cancer between 1995 and 2005 were identified. Patient demographics, mode of bladder management, risk factors and presenting symptoms were recorded along with therapy, pathological findings and outcome. This patient cohort was combined with all prior known published studies for analysis.

RESULTS

Eight patients with a median age of 41 years were treated. Only 1 patient (13%) had undergone bladder augmentation. Locally advanced stage (T3 or greater) or lymph node metastases were present in 88% of cases. Median survival was 6 months with only 1 patient alive with no evidence of recurrence at 20 months. A total of 11 prior published cases were identified and combined with this series. Transitional cell carcinoma was present in 58% of patients. Median survival was 6 months. Only 37% of patients had undergone bladder augmentation.

CONCLUSIONS

Patients with spina bifida and bladder cancer present at a young age with variable tumor histology and advanced stage, and they have poor survival. Presenting symptoms are often atypical and bladder cancer should be a consideration in this patient population, even in young adults. Due to poor survival further study is warranted in this population to determine whether screening would be beneficial for earlier detection and improved outcomes.

Differentially expressed gene networks in cultured smooth muscle cells from normal and neuropathic bladder

Neuropathic bladder dysfunction results from abnormal development of the spine, spinal cord injuries, or diseases such as diabetics. Patients with neuropathic bladders often require surgical intervention such as bladder reconstruction to improve incontinence and prevent renal damage. Tissue engineering with ex-vivo cultured bladder cells has been suggested as one means for improving bladder function. However, we previously demonstrated that cultured bladder smooth muscle cells (SMCs) derived from neuropathic bladder exhibit and maintain altered pathologic phenotypes in culture. To identify genes that are responsible for the abnormal neuropathic phenotypes specifically elevated cell proliferation, the expression levels of 1,185 genes were compared between cultured SMCs derived from normal and neuropathic bladders using a cDNA array consisting of well-annotated genes. The expression data were analyzed using several methods to identify differentially expressed genes. The resulting sets of differentially expressed genes were examined by pathway analysis to identify the networks that remain abnormal in the culture-stable phenotype of neuropathic SMCs. A total of 18 genes that are differentially expressed between cultured normal and neuropathic bladder SMCs were identified. Of these 17 were up-regulated greater than 2-fold in neuropathic bladder SMCs, six of them along with one gene that was not up-regulated greater than 2-fold in cultured neuropathic bladder SMCs were confirmed and identified by more stringent analysis methods including significance analysis of microarrays, class comparison, and class prediction analyses. The major dysregulated pathways include fibroblast growth factor signaling, PTEN signaling, and integrin signaling. Our results further suggest that altered neuropathic bladder SMC phenotypes is stable in the culture environments and that SMCs derived from diseased bladders may not be appropriate for tissue engineering purpose without modification of pathologically altered genes expression.

Adenocarcinoma arising in a gastrocystoplasty

Gastrocystoplasty is a form of surgical bladder augmentation or neobladder used to restore bladder capacity and compliance in children and in patients with neurogenic bladder. Other forms of bladder augmentation include ileocystoplasty and colocystoplasty. Reported complications of gastrocystoplasty include post-operative bleeding, haematuria, stricture, metabolic alkalosis and rupture of the gastric segment. There are reports of adenocarcinomas arising in the setting of ileocystoplasty and colocystoplasty. However, the first case of adenocarcinoma arising in the setting of a gastrocystoplasty is reported.

Histologic findings after gastrocystoplasty in rabbits

PURPOSE

The aim of this study was to investigate the long-term histologic changes after bladder augmentation with gastric segment in an animal subject.

MATERIALS AND METHODS

Gastrocystoplasty was performed in 13 young, 3-month-old male rabbits. Open biopsies were taken from the native bladder and the gastric segment preoperatively and at 3, 6, and 12 months postoperatively. Sections were examined with H&E and periodic acid-Schiff (PAS) staining. Indirect immune peroxidase method was additionally applied to detect the carcinoembrionic antigen, the proliferative activity, and the gene for the tumor protein p53 in the epithelium.

RESULTS

On the native bladder, at the 3-month follow-up, polyps, mucosal edema, submucosal fibrosis, and squamous cell metaplasia were detected, which did not change during the follow-up. On the gastric segment, at the 3-month follow-up, parietal cell hyperplasia and inflammatory mucosal overgrowth were detected; at the 6-month follow-up, inflammation or atrophy of the gastric mucosa and colonic-type metaplasia was found. These alterations remained unchanged during later course of follow-up. Neither dysplasia nor malignancy was observed during the 12-month follow-up.

CONCLUSIONS

The present study supports the clinical observations of low cancer risk after gastrocystoplasty and may indicate different effect of gastric secretion on uroepithelium and that of urine on gastric mucosa.

Anaplastic signet ring cell carcinoma arising in gastrocystoplasty

Augmentation cystoplasty operations using segments of gastrointestinal tract are often necessary in neurogenic low-compliance bladders. Patients are usually rehabilitated with an increase in storage volume and normalization of the reduced compliance. However, gut mucosa-related early and late complications are not very uncommon. Malignancy, although rare, is known to occur after enterocystoplasty, but only one such case has been reported for gastrocystoplasty, a single patient who developed urothelial carcinoma. We describe what we believe to be the first case of signet ring cell carcinoma developing after gastrocystoplasty.

Tumour formation within intestinal segments transposed to the urinary tract

Patients and their urologists are quite rightly concerned about the possibility of neoplastic change within intestinal segments transposed to the lower urinary tract. This fear arises from the occurrence of latent adenocarcinoma arising from the urocolic anastomosis in approximately 10% of patients who underwent ureterosigmoidostomy in childhood. The present text provides an update of previous reviews and details work published since 1990 on epidemiological, experimental and clinical studies. Consideration of the collected evidence confirms the increased risk of colonic neoplasia following mixing of the faecal and urinary stream by ureterosigmoidostomy or its more recent variants. In contrast, the occurrence of tumours within transposed intestinal segments appears more likely to be related to the underlying urinary tract disease for which the surgery was performed rather than exposure of the intestinal mucosa to urine. This conclusion is, however, based on low level evidence and, despite the reassuring findings, caution is advised until more robust data are available to provide a confident risk assessment.