Clonal trisomy 4 cells detected in the ossifying renal tumor of infancy: study of 3 cases.

The ossifying renal tumor of infancy is a rare neoplasm diagnosed in the first 2 years of life, predominantly in boys. The neoplasm is primarily characterized by the presence of a large ossifying component. Its most common mode of presentation is hematuria, and it has a uniformly benign behavior. The karyotypic makeup of the process has not been reported. Thus, a study was undertaken and it allowed demonstration of clonal trisomy 4, which was confirmed by the fluorescent in-situ hybridization-probing of two additional archival formalin-fixed, paraffin-imbedded similar tumors. On the basis of the findings in these three cases, it seems that clonal trisomy 4 may be considered as a characteristic of the tumor, which makes it distinct from any other infantile renal tumor.

Regression of inflammatory pseudotumor of the bladder in a child with medical management.

Inflammatory pseudotumor of the bladder is a benign proliferative lesion of the submucosal stroma that cannot be distinguished from malignant tumors of the bladder either endoscopically or radiographically. Although benign, the proliferative nature of the inflammatory pseudotumor histopathology has led others to recommend open surgical removal or complete transurethral resection for definitive treatment. A limited number of case reports have described inflammatory pseudotumor of the bladder in either adults or children. This is a case of biopsy-proven inflammatory pseudotumor in the bladder of a child that regressed after medical management alone.

Percutaneous extraction of bilateral renal mycetomas in premature infant using mechanical thrombectomy device.

Although mycotic infections of the urinary system occur not infrequently, obstruction of the upper urinary tract because of mycetomas or fungus balls is exceedingly rare. Treatment consists of antifungal treatment and appropriate urinary drainage. In cases resistant to treatment with external drainage and chemotherapy, open surgery is typically performed to remove the mycetoma. However, this can also be achieved percutaneously using mechanical thrombectomy devices, as shown in this case of a 4-month-old infant presenting with renal failure due to bilateral obstructing mycetomas.

Intratesticular varicocele in adolescents: a reversible anechoic lesion of the testis.

PURPOSE: We describe ultrasonographic and clinical findings in adolescents with intratesticular varicocele. MATERIALS AND METHODS: Three adolescent boys 12 to 16 years old each had a large intratesticular multicystic lesion on scrotal Doppler ultrasound for a large extratesticular varicocele. The presence of active Doppler flow within the anechoic lesions supported the diagnosis of intratesticular varicocele. RESULTS: All 3 boys underwent spermatic vein ligation for varicocele. In each case scrotal Doppler ultrasound at 3 months postoperatively demonstrated resolution of the intratesticular anechoic lesions and Doppler flow, confirming the diagnoses of intratesticular varicocele. CONCLUSIONS: Intratesticular varicocele is a clinically occult lesion that may occur in conjunction with extratesticular varicocele. This entity is apparent on scrotal Doppler ultrasound as an intratesticular anechoic lesion with active Doppler flow, and has been shown to resolve following spermatic vein ligation. Its clinical significance has not yet been defined.

Bladder wall necrosis in an extremely low-birth-weight infant: a thought-provoking complication of necrotizing enterocolitis.

An 879-g baby boy had catastrophic necrotizing enterocolitis (NEC) at 29 days of life and underwent surgical laparotomy with a subsequent ileostomy and peritoneal drain placement. The infant was subsequently stable until 42 days of life when a spontaneous perforation of the bladder apex was diagnosed by a suprapubic cystogram. Laparotomy on day of life 46 found a loop of dead bowel herniating into a necrotic hole of the bladder dome. This case shows a previously unreported complication of NEC and discusses the possibility that prolonged use of a peritoneal drain may have permitted its genesis.

Signaling through PI3K/Akt mediates stretch and PDGF-BB-dependent DNA synthesis in bladder smooth muscle cells.

PURPOSE: Smooth muscle cells (SMC) of the bladder undergo hypertrophy and hyperplasia following exposure to sustained mechanical overload. Although superficial similarities in the response of the heart and bladder to hypertrophic stimuli suggest that similar molecular mechanisms may be involved, this remains to be demonstrated. In this study we compared signal transduction pathway activation in primary culture bladder SMC and cardiac myofibroblasts in response to cyclic stretch. The effects of growth factor stimulation on pathway activation in bladder SMC were also investigated. MATERIALS AND METHODS: Primary culture rodent bladder SMC or cardiac myofibroblasts were subjected to cyclic stretch-relaxation in the absence or presence of pharmacologic inhibitors of the phosphoinositide-3-kinase, (PI3K)/Akt, extracellular signal-regulated kinase-mitogen activated protein kinase (Erk-MAPK) or the p38 stress-activated protein kinase-2 (SAPK2) pathways. In parallel experiments human bladder SMC were treated with platelet-derived growth factor-BB (PDGF-BB), heparin-binding EGF-like growth factor (HB-EGF) or fibroblast growth factor-2 (FGF-2). In each case the extent of DNA synthesis was determined by uptake of tritiated thymidine, and activation of specific signaling intermediates was determined by immunoblot analysis using antibodies to the non-phosphorylated and phosphorylated (activated) forms of Akt, p38 and Erk1/2. RESULTS: Akt and p38 were rapidly phosphorylated in stretched bladder SMC and cardiac myofibroblasts, and stretch-induced DNA synthesis in these cells was ablated with inhibitors of PI3K or p38 but not Erk-MAPK. Similarly, PDGF-BB up-regulated DNA synthesis in bladder SMC in a p38 and Akt-dependent manner. CONCLUSIONS: We conclude that distinct stimuli, such as mechanical stretch and PDGF-BB, promote DNA synthesis in bladder SMC through shared downstream signaling pathways. Furthermore, phenotypically similar cells from the bladder and heart show comparable pathway activation in response to stretch. These findings suggest that similar molecular mechanisms underlie the altered growth responses of the bladder and heart to mechanical overload. This study also provides the first report of Akt activation in bladder SMC and suggests that Akt, consistent with its pivotal role in cardiac hypertrophy, may also be a key regulator of remodeling in the SMC compartment of the bladder exposed to hypertrophic/hyperplastic stimuli in vivo.