A needle biopsy is performed under local anesthesia. Simple aspirations are performed with a small gauge needle to attempt to draw fluid from lumps that are thought to be cysts. Fine needle biopsy uses a larger needle to make multiple passes through a lump, drawing out tissue and fluid. Withdrawn fluid and tissue is further evaluated to determine if there are cancerous cells present.
Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.