Introduction to
FNA
FNA can be defined as "the removal of a sample of cells,*
using a fine needle, from a suspicious mass for diagnostic
".purposes
!"Not a "shot in the dark*
FNA generally works best when a lesion is clinically
suspicious (usually of being a neoplasm) and the number of
.diagnostic possibilities is limited
The more refined the question, the more refined the*
.answer
the procedure is usually not therapeutic (except for some*
Diagnostic Uses of FNA
• Neoplasms
The primary use
• Infections
Eg, fungal, viral, protozoal
• Inflammations
Eg, granulomas in sarcoidosis
• Infiltrations
Eg, amyloidosis
Targets
"Superficial "lumps or bumps •
Thyroid, lymph node, breast, etc
Deep, radiologically imaged sites •
Lung, liver, pancreas, kidney, etc
Outpatient office or clinic
Bedside, OR, ER, etc
Technique
Basic Equipment
:Assorted fine needles •
and smaller; various lengths -22
Syringe ("pistol") handle •
Not mandatory, but can be useful
Needle guide (eg, Franzen) •
For transrectal, transvaginal bx
Slides, fixative, alcohol swabs, gauze pads, etc •
Ancillary: eg, culture media •
Needle
A variety of needles, ranging from 27- to 22-gauge, in various
,lengths
A 25-gauge , 1-inch needle is a standard needle that can be
.used to biopsy most superficial targets
A 27-gauge needle is good for sampling vascular organs, *
such as the thyroid or for transthoracic aspirations to reduce
the risk of complications
A 22-gauge needle is good for sampling soft tissue tumors or
when high cell volume is required
Long needles, guided by diagnostic imaging techniqus, can
.reach deep body sites
Intracranial and osseous lesions may require a trocar to
.introduce the needle
To ensure the best outcome for the patient from the FNA
-:procedure, you must
Clinical assess patient prior to procedure/1
Adequately perform the FNA biopsy/2
Make observations during the procedure/3
Prepare quality smears/4
Perform microscopic interpretation/5
Report the results properly /6
Background of FNA procedure [CAP]
Each single needle pass should take less than 5 - 10 seconds/1
to complete
When sampling vascular targets or the thyroid gland, single/2
pass should take 2 - 5 seconds and use smaller gauge needles
,(e.g. 25 or 27 gauge)
Usually 2 - 6 passes are performed on the target for/3
adequate sampling
Using needle only or using an aspiration device with suction/4
may be employed
Number of slides produced will vary on how you are/5
planning on triaging the material obtained and the smearing
technique used
Needle rinses in a preservative solution (formalin) or/6
additional unstained slides may be obtained for special studies
Pre FNA procedure events
:Focused patient history and physical exam/*
A/Obtain patient history
B/Determine site to be biopsied
C/Review any pertinent radiographic imaging and laboratory
studies
D/Inquire about any significant medical problems including
bleeding disorders, anticoagulation, previous episodes of
syncope or complications and perceived problems from other
previous biopsy procedures
E/Perform a focused physical examination
Location relative to other anatomical structures/@
Estimated depth from skin/@
Consistency (firm vs. soft or solid vs. cystic)/@
Mobile vs. fixed/@
Any evidence of pulsation or bruit/@
,F/Explain biopsy procedure in lay terms
G/Address any patient concerns about the procedure
BEFORE proceeding
Ready aspiration setup and supplies (needles, syringes,
slides, special collection tubes for any additional studies)
Performing the FNA procedure
Always follow saftyprecautions/1
Locate and immobilize target with onehand/2
Disinfect the skin with alcohol (70%) at site of/3
planned needle puncture site
Pass the needle through the skin in one quick/4
motion
Usually needle approach is 30 - 45 degree angle to
the skin for very superficial targets
In most cases, the aspirator will notice a/5
difference in the consistency of the tissue of the
target when penetrated
If the target is small, one usually directs the/6
needle toward the center of the target; if the
target is large and there is concern for central
necrosis, the needle should be aimed toward the
Once in the target, you may apply suction if/6
using an aspiration device, and then the needle is
moved in long back and forth cutting motions
within the target (DO NOT let the needle come
out of the skin during this motion)
When blood or material appears in the hub of/7
the needle the aspiration should be stopped
PRIOR to withdrawal of the needle if using/8
suction, negative pressure must be released to
prevent suction of the material into the barrel of
the syringe when the needle exits the skin
Apply pressure to the aspiration site/9
10/Prepare smears (see smear makig) and
obtain needle rinses as needed
French," or nonaspiration technique simply uses"
only a needle to capillary action draws the sample
.into the needle
The volume of the sample tends to be less, but the
concentration of cells tends to be higher, compared
. with aspiration
Advantages of the nonaspiration technique include
increased sampling precision/1
better tactile "feel" of the consistency of the/2
lesion
less bloody specimens/3
much less scary-looking biopsyequipment/4
:Prepaation of smears
cordding to physical properties of FNA material,
for example cyst fluid versus semisolid material
Cells are spread out in a monolayer and stains so
they easily transmit light
Specimen is concentrated enough in a small
portion of slide for ease of screening and
microscopic review
Cells are well preserved without crush artifact
Any semisolid tissue fragments are spread out
with gentle pressure with some remaining intact
Slides are properly labeled
Advantages of FNA
No hospitalization
No return visits
No preparation (diets, enemas, etc)
No great discomfort
No great amount of time
No scar
No stitches
No anesthetic risk (if not used)
No long wait for results
No great cost
Resolve problems as outpatients
Economic
Safe
-:Complications
Infrequent, usually minor Rate increases w/ needle
diameter
Pain: usually minor, well tolerated •
Bleeding: apply pressure •
Light headedness, fainting •
Infection: very rare •
Others •
Lightheadedness/1
Nerve deficit, eg, affecting the recurrent laryngeal/2
nerve following thyroid FNA
Tracheal puncture/3
Xanthogranulomatous sialadenitis has occurred/4
following FNA of parotid Warthin tumor
Pneumothorax/5
-:Contraindications
Bleeding diathesis/1
Patients with suspected vascular lesions (eg/2
arteriovenous malformations, angiosarcomas) are not good
candidates for deep-seated aspirations
Advanced pulmonary emphysema, severe pulmonary/3
hypertension, severe hypoxemia uncorrected by oxygen
therapy, and mechanical ventilatory assistance
Aspirating paragangliomas including carotid body tumors/4
and pheochromocytomas may be associated
,with syncope, acute hypertension
Suspected hydatid disease ,Echinococcus /5
Aspiration of ovarian cysts/6
Uncooperative patient/7
