Urothelial carcinoma following augmentation cystoplasty: an aggressive variant with distinct clinicopathological characteristics and molecular genetic alterations.

Aims: Patients who have undergone intestinal augmentation cystoplasty are at risk for developing latent vesicle malignancy. The aim was to evaluate the histological and immunohistochemical characteristics and molecular genetic alterations in these neoplasms. Methods and results: Four patients developing urothelial neoplasms after augmentation cystoplasty were included in the current study. The mean age of the patients, including two men and two women, was 37 years. The latency from bladder augmentation to developing malignancy ranged from 17 to 21 years (mean 19 years). All patients died of cancer shortly after diagnosis (mean 5 months). In the morphological evaluation, all tumours were high-grade (grade 3) invasive urothelial carcinoma comprising various architectural patterns with brisk mitoses and tumour necrosis. Three harboured glandular differentiation and the remaining one showed squamous differentiation. All cases revealed abnormal decreasing β-catenin expression. Two tumours showed nuclear expression of CDX2. On UroVysion fluorescence in situ hybridization (FISH) analysis, all tumours displayed characteristic chromosomal abnormalities. Point mutations of both FGFR3 and p53 genes were identified in one case. Conclusions: Urothelial carcinomas developed after augmentation cystoplasty are extremely aggressive and exhibit distinct morphological, immunohistochemical and genetic characteristics. UroVysion FISH analysis may offer a surveillance strategy in patients who undergo augmentation cystoplasty. [ABSTRACT FROM AUTHOR]