What is the main function of transurethral resection of bladder tumor (TURBT)?

The main function of transurethral resection of bladder tumor (TURBT) is primarily to diagnose and treat bladder cancer. This procedure involves the removal of bladder tumors through the urethra, allowing for direct access to the bladder without the need for open surgery. During TURBT, not only are tumors excised, but tissue samples are also taken for pathological examination which helps in accurately staging and grading the cancer. This dual role of both therapeutic intervention and diagnostic evaluation is critical in the management of bladder cancer, enabling subsequent treatment decisions.

In contrast, the other options do not reflect the primary purpose of TURBT. Providing chemotherapy is a treatment modality but is not part of the TURBT procedure itself. Assessing kidney function typically involves blood tests or imaging studies rather than this specific procedure, and excising external tumors is not relevant to TURBT, which targets tumors that are located within the bladder itself.