What type of biopsy is used for clinical staging in cases of infiltrating ductal carcinoma?

A core biopsy is used for clinical staging in cases of infiltrating ductal carcinoma because it collects a larger tissue sample than other methods, allowing for more accurate histological evaluation of the tumor. This type of biopsy provides sufficient tissue to assess both the histological grade of the tumor and the presence of certain biomarkers, which are critical for determining the most appropriate treatment plan.

Fine needle aspiration is less invasive but typically retrieves only a small amount of cells, making it more suitable for cytological analysis rather than detailed histopathological assessment. Excisional biopsies involve the surgical removal of an entire lump or suspicious area, which may not always be necessary for staging, as core biopsies can suffice. Incisional biopsies involve removing a portion of the tumor but are generally less preferred for initial staging compared to core biopsies, which provide adequate sampling without having to remove larger tissue areas unnecessarily.

Overall, the core biopsy is the most useful in clinical staging due to its ability to yield a comprehensive and representative sample of the tumor, aiding in establishing an accurate diagnosis and facilitating treatment planning.