Diagnosis basics · 5 min read
What is a biopsy for cancer?
A biopsy removes cells or tissue so a lab can examine them. It is often needed to diagnose cancer or learn more about a tumor.
Written by OncosAI Editorial Team · Editorial review 2026-07-04
Key takeaways
- A biopsy can be done in different ways depending on location and sample needs.
- The sample may be used for diagnosis, grade, subtype, and biomarker testing.
- Ask how the biopsy will be done and what risks to expect.
- Ask whether enough tissue will be collected for molecular testing if needed.
The simple version
Imaging can show that something looks abnormal, but a biopsy is often needed to know what cells are actually present. The sample is sent to a lab where specialists examine it.
Some biopsies use a needle. Others use an endoscope, skin procedure, or surgery. The best approach depends on where the abnormal area is and what information is needed.
What the sample can show
- Whether cancer cells are present.
- What type of cancer it appears to be.
- How abnormal the cells look.
- Whether special stains or biomarker tests are needed.
- Whether there is enough tissue for additional testing.
Questions to ask
- What type of biopsy do I need?
- Will I be awake or sedated?
- What are the risks and recovery instructions?
- How long will results take?
- Will the sample be enough for biomarker testing?
Sources
- American Cancer Society: How Is a Biopsy Done? — Explains biopsy types and sample processing.
- Mayo Clinic: Biopsy — Overview of biopsy procedures used to diagnose cancer.
This guide is educational and does not replace advice from your oncology care team.