The first steps in performing an FNA are palpation and immobilization of the lesion. Palpation is performed at the time of physical examination to investigate the size, mobility, contour and consistency of the mass, and presence or absence of associated tenderness. It is repeated prior to sampling primarily to confirm the location and accessibility of the lesion. Before proceeding with immobilization and sampling of the lesion, children who are developmentally unable to cooperate and are not under general anesthesia must be securely positioned with a nurse and/or parent helping to immobilize their arms and legs. If the child is strong or there are not enough people to assist with the procedure, then a papoose can be utilized to secure the child (Fig. 2.5). In some cases the FNA is performed under conscious sedation or general anesthesia at the request of the parent and/or discretion of the clinician. An ideal time to perform an FNA is when the child is undergoing general anesthesia for another procedure (e.g., FNA of an enlarged cervical lymph node during anesthesia for placement of myringotomy tubes ) and can be optimally positioned with no movement; however, this is not an option in all cases. Once the patient is immobilized, the lesion itself can be immobilized with the fingers of the non-dominant hand, usually the index and middle fingers in order to reserve the thumb for stabilizing the needle and syringe holder. In young or anxious patients, topical anesthetic, such as 4 % topical lidocaine cream, can be applied prior to the procedure to decrease discomfort during the FNA and is typically tolerated better than subcutaneous injection of 1 % lidocaine with 1:100,000 epinephrine.

An FNA typically involves 3–5 needle passes with 22, 23, 25, or 27 gauge disposable hypodermic needles with long bevels. If aspiration is used, a syringe holder is helpful because it allows one to aspirate with one hand and stabilize the target with the other. Most syringe holders accommodate a 10cc syringe, which is easier to manage than those designed for 20cc syringes. Once the lesion is immobilized, the skin overlying the aspiration site is disinfected with an alcohol swab or iodine scrub. The needle is then inserted and a sweeping motion back and forth within the lesion is utilized for about 15 quick excursions or until material appears in the hub of the needle. FNAs can be performed with or without suction . A comparison of these methods is summarized in Table 2.1. FNAs utilizing suction are helpful for obtaining more abundant material for ancillary studies and for draining cystic lesions; however, the increased distance between the aspirating hand and the lesion limits the fine motor control and the size of the device may increase the patient’s apprehension (Fig. 2.6). FNAs performed without suction (capillary method, Zajdela technique , French method , or “non-aspiration aspiration ”) usually yield less material, but the aspirates tend to be less bloody and relatively more cellular making it ideal for sampling highly vascular lesions, such as thyroid nodules (Fig. 2.7). This approach may also cause less anxiety for a young patient because the equipment is limited to a small needle, which is more modest in scale and can be hidden discretely in the operator’s hand. It also offers better fine motor control because of the shorter distance between the lesion and the operator’s hand. This makes it the optimal technique for sampling small, mobile lesions or lesions in non-sedated or anxious patients who are likely to move during the procedure.