Biopsy and FNAC: key differences

FNAC stands for fine-needle aspiration cytology. A clinician passes a thin needle into an area such as a lump or enlarged lymph node and draws out cells for a cytologist to examine. Ultrasound or another imaging method may guide the needle when the area is deep or difficult to feel.

A core-needle biopsy removes narrow pieces of tissue, preserving more of the structure around the cells. A surgical biopsy removes part or all of an abnormal area. Tissue architecture can help a pathologist classify a tumour and may allow additional staining or molecular tests. FNAC can provide useful answers with a small sample, but an unclear or insufficient result may need repeating or following with a core or surgical biopsy.

Tell the procedure team about blood-thinning medicines, bleeding problems, allergies, pregnancy and any infection near the sampling site. Do not stop a prescribed medicine on your own; the clinician arranging the test should give specific instructions. Ask whether you need to avoid food or drink, whether sedation is planned and whether someone must take you home.

Afterward, keep the dressing and site as directed. Mild tenderness or bruising can occur, and simple pain relief may be advised. Check when results are expected and which clinician will explain them. A sample result is interpreted with the examination and imaging rather than treated as an isolated answer.

Contact the procedure team promptly if bleeding continues despite firm pressure, pain is increasing rather than settling, redness spreads, swelling grows, pus appears or you develop fever or chills. Seek emergency care for severe breathlessness, coughing up blood, fainting or rapidly enlarging neck swelling. The relevant warning signs vary with the body area sampled, so follow the discharge instructions provided for your procedure.

Ask why FNAC, core biopsy or surgical biopsy is preferred for this area, how imaging will be used and what anaesthetic or sedation is offered. Clarify whether the sample should be large enough for immunohistochemistry or genomic testing, what an inconclusive result would mean and who will discuss the pathology report with you.