Genomic aberrations are rare in urothelial neoplasms of patients 19 years or younger

Urothelial neoplasms in patients 19 years of age or younger are rare, and the data regarding clinical outcome are conflicting. Molecular data are not available. Urothelial tumours from 14 patients aged 4 to 19 years were analysed, including FGFR3 and TP53 mutation screening, comparative genomic hybridization (CGH), UroVysion FISH analysis, polymerase chain reaction for human papillomavirus (HPV), microsatellite analysis using the NIH consensus panel for detection of microsatellite instability (MSI) and six markers for loss of heterozygosity on chromosome arms 9p, 9q, and 17p and immunohistochemistry for TP53, Ki-67, CK20 and the mismatch repair proteins (MRPs) hMSH2, hMLH1, and hMSH6. Based on the 2004 WHO classification, one urothelial papilloma, seven papillary urothelial neoplasms of low malignant potential (PUNLMPs), five low-grade, and one high-grade papillary urothelial carcinoma were included. No multifocal tumours were found and recurrence was seen in only one patient with a urothelial papilloma. All patients were alive with no evidence of disease at a median follow-up of 3.0 years. We found no mutations in FGFR3, deletions of chromosome arms 9p, 9q or 17p, MSI or MRP loss, or HPV positivity in any of the patients. Three cases showed chromosome alterations in CGH analyses, urothelial dedifferentiation with CK20 overexpression, or aneuploidy, and one TP53 mutation with TP53 overexpression was found. Urothelial neoplasms in people younger than 20 years are predominantly low grade and are associated with a favourable clinical outcome. Genetic alterations frequently seen in older adults are extremely rare in young patients. Urothelial neoplasms in children and young adults appear to be biologically distinct and lack genetic instability in most cases.

CT appearance of some colonic villous tumors

OBJECTIVE

A review was made of the CT studies and pathology reports of four patients with surgically resected colonic villous adenomatous tumors, two of whom had focal carcinomatous invasion.

CONCLUSION

Two patients had villous tumors with IV contrast-enhancing convolutional gyral patterns. The other two patients had tumor masses that showed oral contrast medium collecting in surface interstices, analogous to findings with barium enemas. One of the latter also had an unusual cluster of mesenteric vessels adjacent to the lesion.

Elevated expression of caveolin-1 in adenocarcinoma of the colon

Caveolins 1, 2, and 3 are the principal proteins of caveolae, the vesicular invaginations of the plasma membrane. Several reports have suggested that caveolin-1 may have a role in cellular transformation and tumorigenesis. We studied the expression of caveolin-1 and caveolin-2 in normal epithelium, adenoma, and adenocarcinoma of the colon and their possible role in tumorigenesis. Formalin-fixed, paraffin-embedded sections of 41 cases of adenocarcinoma and 13 cases of adenoma of the colon were stained immunohistochemically with anti-caveolin-1 and anti-caveolin-2 antibodies. The expression of caveolin-1 was elevated in the overwhelming majority of the adenocarcinomas, while most normal colonic epithelium and adenomas showed little or no staining. There was significant statistical correlation of the expression of caveolin-1 with adenocarcinoma but not with tumor stage. Expression of caveolin-2 was undetectable in all of the normal colonic glands, adenomas, and carcinomas. We discuss the possible clinical implications of our findings within the context of caveolins and signal transduction.

Transgenic overexpression of caveolin-3 in skeletal muscle fibers induces a Duchenne-like muscular dystrophy phenotype

It recently was reported that Duchenne muscular dystrophy (DMD) patients and mdx mice have elevated levels of caveolin-3 expression in their skeletal muscle. However, it remains unknown whether increased caveolin-3 levels in DMD patients contribute to the pathogenesis of DMD. Here, using a genetic approach, we test this hypothesis directly by overexpressing wild-type caveolin-3 as a transgene in mice. Analysis of skeletal muscle tissue from caveolin-3- overexpressing transgenic mice reveals: (i) a dramatic increase in the number of sarcolemmal muscle cell caveolae; (ii) a preponderance of hypertrophic, necrotic, and immature/regenerating skeletal muscle fibers with characteristic central nuclei; and (iii) down-regulation of dystrophin and beta-dystroglycan protein expression. In addition, these mice show elevated serum creatine kinase levels, consistent with the myo-necrosis observed morphologically. The Duchenne-like phenotype of caveolin-3 transgenic mice will provide an important mouse model for understanding the pathogenesis of DMD in humans.

Congenital renal arteriovenous malformations

Congenital renal arteriovenous malformations are rare, but their incidence are frequency of recognition are rising. Six cases of both cirsoid and idiopathic varieties are described. Patients were either asymptomatic or presented with gross hematuria and flank pain. Physical findings included hypertension, cardiomegaly, flank tenderness, and an abdominal bruit. IVP findings included filling defects in the renal pelvis from blood clots, irregular mucosal pattersn, or mass effect. Angiography demonstrated either single, simple, vascular channels or multiple, complex, varix-like communications. In both there was early filling of the renal vein, a normal caliber to the feeding artery and draining vein, and no displacement of parenchymal vessles. Asymptomatic patients required no treatment. Surgical procedures that spare renal parenchyma are preferred.

Renal autotransplantation and partial resection of the ureter for recurrent benign ureteral tumor

A report of a patient treated by partial resection of the ureter and renal autotransplantation for recurrent benign ureteral tumors and impaired renal function in the contralateral kidney is presented. Autotransplantation of the ipsilateral kidney associated with benign disease of the renal excretory system is recommended even with normal function of the contralateral kidney. Experience with renal homotransplantation has led to excellent technical and functional results from autotransplantation, and use of the procedure is expanding to include treatment of a variety of renal, ureteral, and renovascular pathology. The role of renal autotransplantation in the preservation of functioning renal units is emphasized.