What is a fine needle aspiration?

A fine needle aspiration (FNA) is a diagnostic tool, which samples a small amount of fluid or tissue extracted by a small fine needle. Samples from the FNA are reviewed by a pathologist, who can confirm a diagnosis. FNAs are performed in the doctor's office and are minimally invasive. They may also be performed under CT or ultrasound. FNAs are not accurate for diagnosis of sarcomas and benign and malignant musculoskeletal tumors. FNAs lack tissue architecture to assess mesenchymal tumors accurately. Core needle biopsies demonstrate architecture and are more accurate for diagnosis of mesenchymal primary bone and soft tissue tumors and sarcomas.

FNA refers to Fine Needle Aspiration and should not be confused with a core needle biopsy. An FNA uses a very fine needle and does not obtain sufficient material for the diagnosis of bone and soft tissue tumors, bone sarcomas/soft tissue sarcomas. It is not used to biopsy tumors of the musculoskeletal system.