THE TECHNIQUE OF FINE-NEEDLE ASPIRATION OF PALPABLE MASS LESIONS OF THE HEAD AND NECK

Transcription

1 THE TECHNIQUE OF FINE-NEEDLE ASPIRATION OF PALPABLE MASS LESIONS OF THE HEAD AND NECK DAVID DUSENBERY, MD This article describes the technique of fine-needle aspiration biopsy in a stepwise fashion. The aspiration procedure is broken down into three phases: The preparatory phase, which includes patient counseling, preparation of equipment and materials, and patient positioning; the actual aspiration; and the specimen handling phase, which includes fixation and smear-making. Indications for the procedure, equipment required, ancillary techniques, and potential complications are also briefly discussed. Although the techniques presented are applicable to palpable masses at any anatomic site, the discussion is tailored to the head and neck area. The technique of fine-needle aspiration (FNA) biopsy consists of a series of discrete steps performed in a relatively rapid, smooth, and fluid manner. As such, it requires forethought and practice to be accomplished correctly. The requisite steps can be divided conceptually into three phases: preparatory, the actual aspiration, and specimen handling. The preparatory phase consists of questioning and examining the patient, obtaining consent for the procedure, preparing and labeling slides, and positioning the patient for the aspiration. The actual aspiration involves immobilizing the mass, cleansing the skin, placing the needle into the mass, and obtaining the specimen. The specimen handling phase consists of smear-making and fixation of slides performed optimally to ensure a top quality specimen for microscopic examination. Although in theory, and in practice when performed by an experienced aspirator, the technique of FNA is elegant and simple, disregard or inattention to any of the component steps may result in a suboptimal specimen. This article will describe the technique for FNA of palpable mass lesions in a stepwise fashion. More comprehensive descriptions of the technique are available, 1-s and the detailed discussion of Stanley and Lowhagen is particularly recommended to the interested reader. 3 Diagnostic considerations of smear interpretation will not be discussed. INDICATIONS AND CONTRAINDICATIONS FOR FNA Some proponents of FNA would consider the presence of any mass lesion in the head and neck to be an indication for the procedure. Others would consider the procedure useful only in answering a specific clinical question. Even those most skeptical of the technique readily acknowledge From the Department of Pathology, University of Pittsburgh, School of Medicine, Pittsburgh, and Laboratory Services, Horizon Hospital System, Greenville, PA. Reprints not available. Copyright 1997 by W.B. Saunders Company /97/ $05.00/0 its utility in diagnosing suspected metastatic carcinoma in cervical lymph nodes. In general, FNA performs optimally when directed at a discrete mass lesion, rather than diffuse swelling. Also, aspiration of neoplastic lesions, rather than inflammatory lesions, tends to result in a more specific and useful diagnosis, although the distinction between neoplastic and inflammatory lesions is not always clear-cut from the clinical examination. When the ancillary techniques of culture and special stains for organisms are added to FNA, it can become a useful procedure for infectious processes. The thyroid gland is an anatomic site in which FNA is widely acknowledged to be the first-line triage test in evaluating a mass lesion. As mentioned previously, enlarged lymph nodes in the neck are also likely targets. FNA of salivary gland swellings is favored by some and discouraged by others. Those critics of the procedure argue that these lesions will need to be excised for definitive diagnosis regardless of the FNA result. However, Frable and Frable have shown a decrease in unnecessary salivary gland surgeries when FNA is applied to salivary gland mass lesions. 6 Other targets in the head and neck include cysts, skin nodules, and intra-oral or parapharyngeal mass lesions. With the use of radiological imaging, the technique can be applied to an even wider range of lesions, but that is beyond the scope of this article. There are relatively few contraindications to FNA in the head and neck. This derives largely from the relatively atraumatic nature of the procedure. Obviously, lesions adjacent to large arteries should be approached with caution. Some authors advise against aspirating carotid body tumors (see following discussion). The use of small bore needles is the key to preventing complications. EQUIPMENT FNA is a powerful clinical tool, yet it is perhaps the simplest of medical procedures, save venipuncture. The equipment necessary to perform an FNA can be carried in a coat pocket (Fig 1). At a minimum, several glass slides, a needle and syringe, and an alcohol swab for cleansing the skin are required. In practice, a hand-held tray or a drawer in the clinic may be stocked with the necessary equipment and materials to perform several FNA biopsies (Fig 2). OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 8, NO 2 (JUN), 1997: PP

2 FIGURE 1. Equipment necessary for performance of FNA: syringe, needles, glass slides, alcohol swab, and syringe holder (optional). Many practitioners use a syringe holder, which allows the aspirator to apply suction with the dominant hand while firmly fixing the mass with the nondominant hand (Fig 3). Fixative, usually 95% ethanol, is necessary if some of the smears are to be stained with Papanicolaou for hematoxylin and eosin stains. Culture medium (Thioglycollate broth) is useful in cases suspected of being infectious in etiology. Tissue fixative (10% neutral buffered formalin) for tissue particles or blood clot for cell block preparation, a slide box for carrying glass slides, cytopathology requisition forms, and perhaps fixative for electron microscopy and medium suitable for flow cytometry may all be useful in individual circumstances. PREPARATORY PHASE The steps before the actual aspiration set the stage and, to a large degree, determine the ultimate success or failure of the procedure. The opportunity to question and examine the patient may play a role in the eventual interpretation of the specimen. For this reason, this author feels that those practitioners who both obtain and interpret the specimen will obtain the highest possible accuracy. If the aspirator and the interpreter are two different people, clear communication between the two is essential. Before the aspiration, several slides should be labeled FIGURE 2. "FNA tray." A hand-held tray can easily be stocked with equipment and materials to perform several FNA biopsies and is convenient for transporting those materials to clinics or hospital rooms. FIGURE 3. Two examples of commercially available syringe holders ("aspiration guns"). Syringe holders are available to hold 10-mL or 20-mL syringes. 62 FNA OF HEAD AND NECK MASSES

3 with the patient's name and arranged on a clutter-free work surface; the fixative should be ready for use, and the syringe holder, syringe, and needle should be assembled and within reach. The next step involves palpating the mass to be aspirated and visualizing the optimal needle approach to the mass. Once the mass has been located and firmly fixed with the nondominant hand, the skin is cleansed with an alcohol swab. Given the small bore needles used in FNA (22 gauge or smaller), local anesthesia is not generally necessar~ THE ASPIRATION The aspiration should be performed with a small bore needle, generally 23 or 25 gauge, of sufficient length to reach the target lesion; 1½-inch needles are usually sufficient in the head and neck area. The aspirator should be cognizant of the fact that the depth of lesions in soft tissue tends to be initially underestimated at the time of palpation. The needle tip is advanced through the skin and into the center of the mass in one smooth, rapid motion. Once the needle is in place, suction is applied to the syringe and the needle tip is moved back and forth within the mass in a series of short, staccato strokes. Before removing the needle from the skin, the suction is released, allowing the plunger to return to its original position. If the needle tip exits the skin while suction is being applied, the diagnostic material may be sucked into the barrel of the syringe where it is less available for rapid smearing. Ideally, the diagnostic material should be confined to the bore (and occasionally the hub) of the needle (Fig 4). During the process of aspiration, the aspirator observes the transparent hub of the needle for the appearance of blood or aspirated material. The appearance of either signals the end of the aspiration. Occasionally blood appears almost immediately, but in other instances, 10 to 20 excursions with the needle can be performed before obtaining material in the hub. To continue the aspiration process beyond this point results in an aspirate sample diluted with blood and offers no diagnostic advantage. An exception is the aspiration of cystic masses. When a cyst is encountered, every attempt should be made to completely evacuate the cyst. This may require multiple repositionings of the needle tip if the cyst is multiloculated. After evacuation of the cyst contents, repalpation and reaspiration of any residual mass are mandatory to avoid a false-negative diagnosis in a partially cystic neoplasm (this may occur in papillary carcinoma of the thyroid). SPECIMEN HANDLING PHASE As mentioned previously, the aspirator should have glass slides labeled with the patient's name ready to accept the specimen before performing the aspirates. After the needle has been removed from the skin, the material is quickly and gently expressed onto the slides. This is done by removing the needle from the syringe, drawing air into the syringe, reattaching the needle, and expelling one to two drops of material onto each slide. Subsequently, direct smears are made by gently spreading the material with another glass slide (Fig 5). Detailed descriptions of slide handling and smear-making are available elsewhere. 1-3,5,7 Before undertaking the practice of FNA, practitioners must become proficient in smear-making techniques. This aspect of FNA is frequently the downfall of those who only dabble in the procedure. A defect in this one stage can render an otherwise adequate specimen useless. The mode of fixation will vary depending on which stains are to be performed, but ideally some of the smears should be rapidly fixed in 95% ethanol for Papanicolaou staining, and some smears should be allowed to air-dry for subsequent staining by one of the Romanovsky-type stains. Alcohol fixation, if desired, must occur immediately after smears are made. Delaying fixation for even one second may introduce air-drying artifact to the specimen, so that smears must literally be made above the open mouth of the Coplin jar waiting to accept them. An alternative method to immediate fixation with alcohol which results in high quality smears without the possibility of air-drying artifact is the method of saline rehydration of air-dried smears. 8 To use this method, the smears are first allowed to air-dry completely; next, after returning to the laboratory, the smears are "rehydrated" in normal saline for 30 seconds to 1 minute; and, finally, they are placed directly into 95% ethanol. The slides can be subsequently stained by the Papanicolaou method or by hematoxylin and eosin. This method is advantageous when air-drying artifact is considered a problem because its use completely eliminates this artifact. It has the added benefit of lysing some of the red blood cells in the smears. Whatever method is used, the entire preparatory process should be rapid and smoothly executed. This obviously requires practice and proficiency at smear-making. Fresh specimens from the surgical pathology bench, autopsies, or fresh beef liver are suitable materials to practice smearmaking techniques before actual patient FNA. The final result should be an evenly spread cellular preparation, which occupies an area of the slide approximately the size of a nickel or a quarter (Fig 6). This author finds direct smearing the most useful means of preparing material obtained by FNA; however, brief mention of other options is indicated. Needle rinses (with normal saline or some other physiological solution) can be used to supplement, or in some instances, replace, direct smears. The rinse solution can be processed onto glass slides by cytocentrifugation. This procedure may be helpful in instances in which the need for multiple special stains is anticipated, but the material is limited in amount. Multiple cytocentrifugation slides can be prepared from a low-volume needle rinse. Preparation of a "cell block," material permitting, is often useful is providing a diagnosis from FNA material. A cell block is prepared from solid tissue fragments or blood clot present in the aspirate and is processed using histological technique identical to that used for surgically obtained tissue. The cell block material often provides a clue regarding tissue architecture and has the added advantage of being familiar to surgical pathologists. A cell block is also the preferred substrate for performance of immunoperoxidase stains. If grossly purulent material is obtained, some of it should be submitted to the microbiology laboratory for culture. Other ancillary techniques such as electron microscopy, flow cytometry, and cytogenetics can be applied to FNA specimens in selected instances. SPECIAL CONSIDERATION IN HEAD AND NECK FNA PATIENT POSITIONING Patient positioning is an important consideration for FNAs performed in the head and neck area. Most aspira- DAVID DUSENBERY 63

4 A_ C B 1 1) F_, 0 F G C. I_1 I~ I-I i_} [~-- FIGURE 4. Line drawing illustrates the sequence of steps in the FNAtechnique: (A) insert needle tip into mass, (B) apply suction to syringe, (C) move needle back and forth in mass, (D) release suction and allow negative pressure to equalize, (E) remove needle tip from skin, (F) detach needle from syringe, (G) draw air into syringe, (H) reattach needle to syringe, (I) expel aspirated material onto glass slides. 64 FNA OF HEAD AND NECK MASSES

5 FIGURE 5. One method of making direct smears is illustrated in this sequence of photographs: (A) Expel aspirated material onto glass slide, (B) while grasping and supporting the slide containing the specimen with the nondominant hand, bring a second ("spreader") slide in contact with the first slide perpendicular to it. Pivoting on the rear edge of the "spreader" slide, gently rotate it until it is flat against the slide containing the specimen. (C, D & E) Applying gentle pressure, and maintaining the two slides in a flat orientation, bring the spreader slide toward yourself (as indicated by the arrow) gently spreading the material over the first slide. tions can be performed in a clinic chair with a headrest. Resting the patient's head against the headrest helps prevent sudden movements during the aspiration and also allows the sternocleidomastoid muscles to relax, facilitating palpation and aspiration. The muscle should be avoided if possible because traversing it is painful and will often DAVID DUSENBERY "plug" the needle, preventing acquisition of an adequate sample. Occasionally, turning the head slowly to one side or the other may bring small or deep masses into prominence. Knowledge of the anatomic relationships in the head and neck is useful in avoiding structures such as the 65

6 FIGURE 6. The desired result is a smear with the aspirated material evenly spread over the central portion of the slide, carotid artery and trachea, although inadvertent puncture of these structures with small needles is usually without lasting ill-effect. Thyroid gland aspirations are best performed with the patient in a supine position, with the aspirator standing on the opposite side from the nodule to be aspirated. The nodule can be pinned between two fingers of the nondominant hand with slight medial traction against the trachea for the aspiration. Placing a pillow between the patient's shoulders allows the shoulders and head to fall back, bringing the thyroid into prominence. The patient should be instructed not to swallow during the procedure. Aspiration biopsy in the supraclavicular fossa should be approached carefully with attention to the close proximity of the pleural cavity at the lung apices. ORAL/PARAPHARYNGEAL SPACE FNA Performance of intra-oral FNA is greatly facilitated by a strong directed light source. In general, these aspirates are performed similarly to other superficial aspirations with a few modifications. Use of a topical spray anesthetic is recommended. Spinal needles are usually of sufficient length to reach most targets without inserting the syringe into the patient's mouth. The best exposure and visualization are often obtained by grasping and applying slight traction to the patient's tongue between gauze pads with the aspirator's gloved, nondominant hand, leaving the dominant hand free to perform the FNA. Tongue depressors and retractors may be useful in gaining exposure. Under no circumstances should the aspirator's fingers be allowed to come between the patient's teeth. OCULAR ADNEXAAND GLOBE All but the most superficial ocular adnexal lesions should be approached only by an experienced ophthalmic surgeon? Otherwise, the procedure for lesions within or around the orbit is identical to that already discussed. THE USE OF THE 'NON-ASPIRATION TECHNIQUE' It has been shown that applying negative pressure during the biopsy is not necessary to procure a good sample 1 and, furthermore, it may occasionally be detrimental. This is especially true in richly vascular anatomic sites, such as the thyroid gland, where aspiration results in an excessively bloody specimen. The non-aspiration method is similar to that used in conventional FNA except that the biopsy is performed with the needle alone without the syringe. The method relies on capillary action to obtain cells within the bore of the needle. A syringe may be attached to the needle to enable easier handling, but the plunger must be removed to allow cells to freely enter the needle bore. The non-aspiration technique is also useful in situations requiring precise needle placement such as the aspiration of very small skin nodules. Grasping the needle in a "pencil grip" allows for the manual dexterity required to enter these difficult targets. Anecdotally, in this author's opinion, the non-aspiration technique is less effective than the traditional method when aspirating hypocellular, fibrous lesions. COMPLICATIONS OF FNA IN THE HEAD AND NECK AREA NEEDLE TRACT SEEDING BY TUMOR Needle tract seeding by malignant tumor cells is an exceedingly rare event when needles smaller than 22 gauge are used. This author is aware of only two reports of needle tract seeding occurring after FNA in the head and neck. One case was that of a follicular carcinoma of the thyroid, which recurred in the skin at the site of a previous FNA performed with a 22-gauge needle, lj The other was a papillary carcinoma of the thyroid, which developed at the site of FNA 3 weeks after an FNA with a 25-gauge needlej 2 However, this latter patient was subjected to FNA biopsies 5 and 7 years earlier with 20 and 21 gauge needles and, therefore, the needle tract seeding cannot be conclusively attributed to the 25-gauge needle aspiration. 12 Given the large number of head and neck FNAs that are performed relative to the number of reported cases of needle tract seeding, this cannot be considered a significant complication of the procedure. ECCHYMOSIS AND HEMATOMA The potential complications of ecchymosis and hematoma formation may be minimized by having an assistant, or the patient, apply direct firm pressure to the aspiration site immediately after the needle is withdrawn. If inadvertent carotid artery puncture occurs, direct pressure should be applied for at least 5 minutes and the patient should be observed following the aspiration. When performing aspirations in the head and neck, the needle should always be withdrawn along the same tract that it was inserted to avoid shearing forces, which could result in a laceration to an artery (rather than a simple puncture injury, which is more easily controlled). TRACHEAL PUNCTURE Tracheal puncture may occur during thyroid FNA biopsy. This event is signaled by "loss of suction" in the syringe. The patient invariably coughs and occasionally may bring up a small amount of blood. Although this is often a somewhat startling event for both the patient and the aspirator, it is short-lived and self-limited. VASOVAGAL REACTIONS Vigorous palpation of the neck or the action of FNA itself may occasionally result in a vasovagal reaction. The patient will almost always report the symptoms to the 66 FNA OF HEAD AND NECK MASSES

7 aspirator. In such cases, the aspiration should be stopped immediately and the patient should be placed in a "head down" position. CAROTID BODY TUMORS A word of caution regarding FNA of carotid body tumors (paragangliomas) is in order. Some authors advise against puncturing carotid body tumors 13,14 and others do not. 15 This author has aspirated a small number of these tumors, not always knowingly, without significant incident. Nevertheless, a tumor situated in an anatomic location that raises the possibility of a carotid body tumor (lesion at the carotid bifurcation) should be approached with caution and certainly with a very small bore needle such as a 25- or 27-gauge needle. Ausculation over these tumors occasionally reveals a bruit that may serve as a warning. The danger of aspirating these tumors derives from their rich vascularity and from their close proximity to the carotid artery. CONCLUSION When performed properly by an experienced aspirator, FNA is a rapid, accurate, and cost-effective technique for the diagnosis of head and neck mass lesions. In this setting, the overall sensitivity of the procedure is about 95%, with a specificity of approximately 98%. 4 The unsatisfactory rate ranges from 0% to 20% and is largely dependent on the experience of the aspirator. 4 ACKNOWLEDGMENTS The author thanks Ronald Thompson for photographic assistance and Esther LaMotte for typing the manuscript. REFERENCES 1. Frable WJ: Thin-needle aspiration biopsy, in Bennington J (ed): Major Problems in Pathology, Vol. 14. Philadelphia, PA, Saunders, Ljung BM: Principles of aspiration biopsy: Techniques of aspiration and smear preparation, in Koss LG, Woyke S, Olszewski W (eds): Aspiration Biopsy: Cytologic Interpretation and Histologic Basis, 2nd ed. New York, NY, Igaku-Shoin, Stanley MW, Lowhagen T: Fine Needle Aspiration of Palpable Masses. Boston, MA, Butterworth-Heinemann, DeMay RM: The Art and Science of Cytopathology. Chicago, IL, ASCP Press, Powers CN, Frable WJ: Fine Needle Aspiration of Biopsy of the Head and Neck. Boston, MA, Butterworth-Heinemann, Frable MAS, Frable WJ: Fine needle aspiration biopsy of salivary glands. Laryngoscope 101: , Abele JS, Miller TR, King EB, et al: Smearing techniques for the concentration of particles from fine needle aspiration biopsy. Diagn Cytopathol 1:59-65, Chan JKC, King ITM: Rehydration of air-dried smears with normal saline: Application in fine-needle aspiration cytologic examination. Am J Clin Pathol 89:30-34, Kennerdell JS, Slamovits TC, Dekker A, et al: Orbital fine-needle aspiration biopsy. Am J Ophthalmo199: , Zajdela A, Zillhardt P, Voillemot N: Cytological diagnosis by fine needle sampling without aspiration. Cancer 59: , Panuzi C, Paliotta DS, Papini E, et al: Cutaneous seeding of a follicular thyroid cancer after fine-needle aspiration biopsy? Diagn Cytopathol 10: , Hales MS, Hsu FSF: Needle tract implantation of papillary carcinoma of the thyroid following aspiration biopsy. Acta Cyto134: , Engzell V, Franzen S, Zajicek J: Aspiration biopsy of tumors of the neck. II. Cytologic findings in 13 cases of carotid body tumor. Acta Cytol 15:25-30, Koss LG, Woyke S, Olszewski W: Aspiration Biopsy: Cytologic Interpretation and Histologic Basis, 2nd ed. New York, NY, Igaku- Shoin, Fleming MV, Oertel YC, Rodriguez ER, et al: Fine-needle aspiration of six carotid body paragangliomas. Diagn Cytopathol 9: , 1993 DAVID DUSENBERY 67