A biopsy is a medical procedure used to take a sample of abnormal tissue in the body, according to WebMD. The tissue sample allows the physician to evaluate the abnormal cells to diagnose a medical condition or develop a treatment plan.
Biopsies are often used to diagnose cancer after finding a mass or abnormal area. While imaging tests may show the mass, physicians can't determine if the cells are cancerous, notes Mayo Clinic. The biopsy provides an accurate diagnosis by evaluating the actual cells from the area.
The location of the abnormal cells determines the type of biopsy performed, states WebMD. A needle typically goes into the area to collect the sample. CT scans or ultrasounds sometimes help guide the needle to the area within the body. A pathologist analyzes the cells after collection to make a diagnosis.