A biopsy is a procedure to obtain a sample of soft tissue, fluid or bone that is sent to a laboratory for analysis. The analysis is done by a specialized physician known as a pathologist. A biopsy is the definitive procedure for the diagnosis of cancer. There are several major types of biopsies and those most often used to diagnose cancer include:

• Fine needle aspiration (FNA). A very thin needle and a syringe are used to withdraw small amounts of fluid or a few cells from a tumor mass or a suspected area of abnormality.
  
  
• Core needle biopsy. A larger needle removes a cylinder of tissue.
  
  
• Incisional biopsy. Small portion of tumor is removed through an incision in the skin.
  
  
• Excisional biopsy. Entire tumor is removed through an incision in the skin.

If the suspected area is not in or under the skin, the biopsy may be obtained in one of several ways.

• Endoscopy. Thin tube with fiber optic light and a viewing lens is inserted into a natural body opening, (e.g., mouth, anus) to view a suspicious area and remove a tissue sample.
  
  
• Laparoscopy. This procedure is similar to endoscopy except the tube is inserted through a small incision in the abdomen to view the inside of the abdomen and remove samples. When the same procedure is performed in the chest, it is called thoracoscopy.
  
  
• Laparotomy. Surgical technique that uses a large incision into the upper abdomen to explore a suspicious area. It is used when a laparoscopy cannot be used to obtain a diagnosis. A thoracotomy is a similar procedure performed in the chest area.
  

Based on the analysis performed on the biopsy material, the sample can usually be diagnosed as cancerous (malignant) or noncancerous (benign). Additional information, such as the type of cancer and its grade, can also be determined from most biopsies. Treatment will be based on the results of the biopsy as well as other factors.