Question: How is the diagnosis of breast cancer established?
Answer:
By tissue examination. This may be done by percutaneous fine-needle aspirate, with or without x-ray direction, or by incisional or excisional biopsy. While mammograms are essential in screening and localizing tumors, up to 15% of breast cancers may not be seen on mammogram, and the diagnosis cannot be made definitively without tissue confirmation. Any clinically suspicious mass must be biopsied.
Reference: Calabresi P, Schein PS (eds): Basic Principles and Clinical Management of Cancer, 2nd ed. New York, Macmillan, 1993
