Library · Procedure
Core needle biopsy
Make it clearer
A core needle biopsy takes a small piece of tissue from a suspicious area so a pathologist can look at it under the microscope. The needle is hollow, and its thickness is measured on a scale called gauge: the ones used here run from 12 to 16.
Inside, the device runs on a spring. First it fires a thin rod, the stylet, into the lesion; right behind it a cutting cannula, a tube with a sharpened edge, shoots forward and slices around it. What ends up trapped inside is a cylinder of tissue, the way an apple corer pulls out a cylinder.
Coming out as a cylinder rather than a smear is exactly what matters. The tissue keeps its architecture, meaning how the cells are arranged in relation to one another, and that shows whether cells are pushing into places they do not belong, which is called invasion. A fine needle, the skinny one, brings back only loose cells: good for looking at them one by one, which is cytology, but not for seeing the arrangement.
And there is one last step that gets overlooked: what the imaging said and what the microscope said have to agree. If the imaging points to something worrying and the tissue comes back benign, the case is not closed: the sample is taken again, or the whole lesion is removed surgically.
In brief
A core needle biopsy uses a hollow 12 to 16 gauge needle to remove a cylinder of tissue.
A spring-loaded device fires a stylet into the lesion and a cutting cannula shears off the core.
That core preserves tissue architecture and allows invasion to be assessed; a fine needle yields only cytology.
It does not take loose cells: it takes a core with its shape intact.
If imaging and pathology disagree, the sampling is repeated or the lesion goes to surgical excision.
Sources (1)
- National Center for Biotechnology Information, StatPearls PublishingImage-Guided Breast Biopsy, StatPearlsPublished
This page explains the topic in general terms; it does not tell anyone what treatment to follow.
Updated