Pathology of superficial bladder cancer with emphasis on carcinoma in situ.

The coexistence of carcinoma in situ in flat epithelium adjacent to tumors is prognostically significant and is associated with an increased incidence of tumor recurrence and invasion. Recent investigations have been aimed at finding markers that will help identify flat areas of dysplasia or low-grade papillary transitional cell carcinomas that have a high potential to evolve into invasive tumors. Both DNA and karyotype analyses, as well as cell surface markers, have been examined in some detail and could have clinical value in certain settings. The tumor DNA index as measured by flow cytometry of nuclei retrieved from deparaffined sections may be particularly useful as a predictor of tumor recurrences and, possibly, tumor invasion as well. The diagnosis of superficial disease rests on urine cytology and the histopathologic assessment of tissue biopsies; however, intra- and inter-observer reproducibility of tissue and cytologic diagnoses by pathologists is a significant problem. The application of new technologies, such as flow cytometric analysis of deparaffined nuclei, may reduce the subjectivity involved in the light microscopic assessment of pathology specimens.