A tissue biopsy is a medical procedure that involves taking a small sample of tissue from the body for examination. This sample can help diagnose diseases, including cancer, by allowing doctors to analyze the cells under a microscope. Biopsies can be performed using various methods, such as needle aspiration, excisional biopsy, or endoscopic biopsy, depending on the location and type of tissue being examined. After the tissue is collected, it is sent to a laboratory where pathologists, specialists in diagnosing diseases, evaluate the sample. The results can provide crucial information about the presence of disease, its type, and how aggressive it may be, guiding treatment decisions for patients.