What is the gold standard for diagnosing breast cancer?

The definitive method for diagnosing breast cancer is the histopathological examination of biopsy specimens. This process involves the microscopic examination of tissue samples obtained from the breast, allowing for the identification of cancerous cells and the determination of cancer type and grade. Histopathology provides detailed information about the biological characteristics of the tumor, which is crucial for treatment planning and prognosis.

Imaging techniques like MRI and ultrasound can assist in detecting abnormalities and guiding biopsies but cannot provide the cellular-level information needed for a diagnosis. Similarly, while Paget's disease assessment can have implications in breast cancer diagnosis, it specifically relates to a type of cancer that affects the nipple and does not serve as a general diagnostic standard for all breast cancers. Therefore, histopathological examination remains the cornerstone in confirming breast cancer diagnosis, guiding clinical management effectively.