When is an image guided percutaneous core biopsy required as opposed to a percutaneous fine-needle aspiration (FNA)?
When architectural detail is needed for histopathologic diagnosis (e.g., well-differentiated neoplasms) and staging (e.g., staging fibrosis of diffuse liver diseases), a core biopsy is required.
FNA specimens are usually obtained using 22- to 25-gauge needles and yield clusters of cells and occasionally small tissue fragments for cytopathologic examination.
Core biopsies are performed using disposable, spring-loaded, automated devices (20 gauge or larger) and yield cylinders of tissue 1 to 2 cm long.
