Biallelic PMS2 mutations and a distinctive childhood cancer syndrome.

Biallelic mutations in PMS2, a gene usually associated in heterozygous form with hereditary nonpolyposis colorectal cancer (HNPCC), results in a recently described childhood cancer syndrome. The tumor spectrum encompasses atypical brain cancers, hematologic malignancies, and colonic polyposis and cancer. Cutaneous stigmata resembling café-au-lait macules with more diffuse margins are frequently seen. Onset is as young as 2 years. The risk of second malignancy is high. Evidence exists for surveillance for bowel cancer, but surveillance for the wider tumor spectrum is of uncertain benefit. We report a consanguineous Australian-Lebanese family with multiple affected individuals shown to be homozygous for a PMS2 exon 7 deletion. We also review published cases of biallelic mutations in HNPCC-related genes. Early recognition of this familial cancer syndrome is critical, and should prompt investigation for familial HNPCC mutations.

Guide wire-assisted urethral dilation in pediatric urology: experience of a single surgeon.

INTRODUCTION: A simple technique to dilate urethral stricture using guide wire and sheath dilator has been described in pediatric urology. The aim of this study was to report the long-term outcome of the children who underwent dilation of the urethral stricture using guide wire and sheath dilator. MATERIALS AND METHODS: From 1999 to 2004, a total of 52 children with documented urethral stricture were managed by urethral dilation using guide wire. Data on the cause of urethral stricture, operation, postoperative recovery, follow-up cystoscopic appearance, and patient's outcome were audited and analyzed. RESULTS: The mean age of the patients was 5.6 +/- 2.3 years (range, 2 to 18 years). The mean period of the follow-up was 4.5 +/- 2.4 years (range, 3.8 to 6.5 years). Twenty-two patients (42.3%) did not require any further surgical treatments. However, urethral stricture in 13 patients (25.0%) progressed significantly, and therefore, they needed further surgical interventions. The complications included minor urinary tract infections in 3 and bladder spasm in 2 patients. No case of false passage or sepsis was encountered. CONCLUSION: Guide wire-assisted urethral dilation avoids the risks associated with blind dilation techniques and continues to be a safe alternative for urethral strictures in selected cases. However, in our experience, less than half of the patients became "recurrence free" after two dilation attempts. We recommend that urethral dilation be considered only in selected cases and emergency settings.

Autoaugmentation gastrocystoplasty: further studies of the sheep model.

OBJECTIVE: To report our experience with autoaugmentation gastrocystoplasty (AAGC, reported to result in an inconsistent augmentation effect in children) in a sheep model, specifically addressing issues of surgical techniques and postoperative bladder drainage that may affect the augmentation result, as many factors have been implicated in the poor outcome. MATERIALS AND METHODS: Ten 6-month-old male lambs had a suprapubic catheter placed by an open laparotomy. Intraoperative urodynamics were evaluated before and after detrusorotomy for autoaugmentation and after completing AAGC. The bladder was drained with no distension for 1 week after surgery and the urodynamic evaluation repeated on control and experimental animals 6 months after surgery. The animals were then killed and the bladders evaluated for gastric flap survival and histological changes in the native bladder and augmentation segments. The results were analysed using a one-sided Student's t-test. RESULTS: The median (range) native bladder volume at leak-point pressure was 110 (40-490) mL. Intraoperative bladder volumes after completing AAGC confirmed adequate augmentation segments in all animals. The urodynamic evaluation at 6 months after AAGC showed increases in bladder volumes in nine of 10 animals (0-1336 mL), significantly greater than the increase in volume in the control sheep (median 337.5 vs 115.3 mL; P < 0.05). The bladder compliance (volume/pressure at leak capacity) 6 months after AAGC was slightly better but not significantly higher than in controls (median 17.3 vs 10.8 mL/cmH(2)O; P > 0.05). The median (range) ratio of surviving gastric flap to native bladder circumferences was 34.5 (31-53)%. Histology showed scarring of the submucosal layer in one of 10 augmentation segments and normal urothelium in all bladders. CONCLUSION: AAGC produces reliable bladder augmentation and excellent bladder compliance in a sheep model of a non-neurogenic bladder. The gastric flap survived well and there was no bladder wall separation with simple postoperative catheter drainage.