Cytologic and histologic features of superficial bladder cancer.

Despite technologic advances in diagnostic skills, cytologic and histologic evaluation is still the standard for the identification of bladder cancer, and these two techniques are critical in therapy selection and post-treatment surveillance. The key to the proper interpretation of cytologic specimens lies in appropriate collection and handling of the sample. Because treatment differs according to the histologic type of a tumor, when a mixture of types is found, all should be listed with their relative proportions. Both pathologists and urologists must be aware of the importance of the muscularis mucosae; a transitional-cell carcinoma may invade this layer without extending into the true muscle.