Depending on what type of lesion (lump) it is and where it is in the body, the actual biopsy takes only a few minutes. However, since the FNA is being performed by a cytopathologist, (Dr. Nadelman), the material is checked immediately under the microscope as you wait, to ensure that there is enough material to make a diagnosis later on. This is done to decrease the chance of having to come back for a repeat FNA because of not enough material. Due to this, the procedure may take up to 45 minutes (per site).