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22719 Core Biopsy of Masses and Solid Organs
Fine Needle Aspiration (FNA) of the Thyroid Gland
Ranjith Vellody
20
Introduction
Thyroid cancer is the most common endocrine
malignancy in children [1] and is increasing in
both incidence and prevalence. Risk factors for
thyroid cancer in children are radiation exposure
(such as prior therapy for lymphoma), female
gender, and family history [2]. Children have the
same types of thyroid cancer as seen in adults
(papillary, follicular, medullary, anaplastic);
however, children often present with more advanced disease [2]. Data have shown that thyroid
nodules in children are more likely to be malignant than adults. In spite of this, children have a
better prognosis. Factors which worsen the prognosis include male sex, nonsurgical treatment,
non-papillary type cancer, and patients with distant metastases [3].
Guidelines from Society of Radiologists in
Ultrasound (SRU) and the American Association
of Clinical Endocrinologists do not specifically
mention the management of thyroid nodules in
children [4, 5]. However, the revised 2009 guidelines from the American Thyroid Association do
suggest that the management of pediatric thyroid
nodules should be the same as adults [3].
A detailed clinical history and physical examination are performed with an emphasis on
R. Vellody ()
Department of Radiology, University of Michigan,
1500 E. Medical Center Drive, Room UH B1-0502,
Ann Arbor, MI 48109, USA
e-mail: ranjithv@med.umich.edu
© Springer International Publishing Switzerland 2016
S. Scholz, M. D. Jarboe (eds.), Diagnostic and Interventional Ultrasound in Pediatrics
and Pediatric Surgery, DOI 10.1007/978-3-319-21699-7_20
detecting signs and symptoms of thyroid disease.
Laboratory values including a serum TSH are
then drawn. If TSH levels are normal or high, a
diagnostic ultrasound may be performed. Several ultrasound characteristics of the thyroid
gland are important to evaluate. These include
whether the disease process is diffuse versus
focal, the number and size of the lesions present,
and whether lesions are solid, cystic, or mixed
(Fig. 20.1 and 20.2). In addition, the presence of
calcifications, colloid, associated vascularity, and
levels of pathologically enlarged lymph nodes
should be documented. Typically, descriptors in
the thyroid ultrasound report suggesting that a
process may not be benign include the presence
of macrocalcifications or microcalcifications, absence of a halo, increased vascularity, solid composition, and irregular margins (Figs. 20.3, 20.4
and 20.5).
Based on the SRU consensus statement, fine
needle aspiration (FNA) is suggested for a thyroid nodule of 1.0 cm or larger if microcalfcifications are present, 1.5 cm or larger if the nodule is
solid with coarse calcifications, 2 cm with mixed
solid and cystic components, or nodules that have
substantial growth over an interval period [6]. As
reflected in the SRU guidelines, ultrasound characteristics are more important than size when determining whether a nodule should be sampled.
The cytopathology result of the FNA determines whether observation, repeat FNA, or surgery should be performed. With respect to the
cytopathology result, the Bethesda Classification
System for Reporting Thyroid Cytopathology
229
230 R. Vellody
Fig. 20.1 Transverse ultrasound image of the right lobe
demonstrates a thin-walled anechoic structure with posterior acoustic enhancement in the thyroid gland. This is a
simple benign cyst
Fig. 20.3 a Transverse thyroid ultrasound image reveals
microcalcifications (arrow) within a solid nodule in the
left lobe of the thyroid. Fine needle aspiration of the lesion was significant for papillary thyroid carcinoma. b
Transverse image of lymph node in the right neck adjacent to the carotid artery in the same patient. Note the
similar sonographic appearance to the primary thyroid
lesion (arrow)
Fig. 20.2 Transverse ultrasound image of the right lobe
of the thyroid demonstrating a mixed solid and cystic
nodule. Targeted FNA of the solid portion of the lesion
revealed papillary thyroid carcinoma
allows for standardization which in turn dictates management [7]. Every FNA report groups
the cytopathology into six distinct categories.
Each category has an associated risk for malignancy and a recommended management scheme
(Table 20.1).
Fig. 20.4 Coarse calcifications within a thyroid nod-
ule. Note the posterior shadowing from the calcifications
(arrow). FNA revealed papillary cancer
23120 Fine Needle Aspiration (FNA) of the Thyroid Gland
inherent risks and every case should undergo
an appropriate risk/benefit analysis. However,
it is best to err on the side of increased patient
comfort and hence decreased patient motion as
adjacent structures can be inadvertently damaged
even with a small-gauge needle.
Some practitioners perform FNA of thyroid
without ultrasound. Although ultrasound guidance may add slightly to the cost and length of
the procedure, it is felt to provide more accurate
diagnostic information. This is particularly true
when nodules cannot be palpated, when there is
some alteration in anatomy, and when a specific
thyroid nodule needs to be sampled in the setting of multiple nodules. Additionally, ultrasound
allows for targeting of the solid components of
a lesion that has mixed solid and cystic characteristics and allows for the visualization of larger
vasculature that should be avoided.
Pre-procedural Management
The most important aspect of pre-procedural
management is confirming that there is a documented indication for the biopsy. All prior im-
Fig. 20.5 a Transverse ultrasound images of the thyroid
in a 10-year-old female. A dominant nodule path proven
to be papillary thyroid carcinoma is noted within the right
lobe of the thyroid. b Color Doppler demonstrates hypervascularity of the lesion
aging studies should be reviewed. Most practitioners agree that anticoagulants, including antiplatelet agents, should be held for 4–7 days prior
to the FNA procedure. In some instances, antiplatelet agents may be difficult to hold. Thyroid
lesions can still be safely biopsied in this clinical
FNA in children presents a unique challenge
as opposed to adults. While most adults can
lie still for an FNA, children may require local
anesthesia, intravenous conscious sedation, or
even general anesthesia. Anesthesia does carry
Table 20.1 The Bethesda classification system for thyroid malignancy
Classification Risk of malignancy (%) Management
Nondiagnostic 1–4 Repeat FNA
Benign <5 Follow up ultrasound in 6–18 months
Follicular lesion of uncertain significance 5–15 Follow up ultrasound +/− repeat FNA in 3–6
Follicular neoplasm, Hürthle cell neoplasm 20–30 Surgical lobectomy
Suspicious for papillary thyroid cancer 60–75 Thyroid lobectomy/total thyroidectomy
Papillary thyroid cancer 98 Total thyroidectomy
FNA Fine needle aspiration
setting as long as the procedure is meticulously
performed. Informed consent with documentation of the risks of the procedure should be obtained from the patient or legal guardian. It is also
prudent to discuss each case individually with the
months
232 R. Vellody
anesthesia provider to determine whether local
anesthetic alone, intravenous sedation, or general
endotracheal anesthesia will be required. If the
institution has the capability, having an on-site
cytopathologist during the procedure can eliminate unnecessary needle passes through the thyroid lesion and limit the amount of nondiagnostic
biopsies.
Technique
Once the child is in the procedure room, patient
verification is performed. A preliminary thyroid
ultrasound should be performed at this time to
document the continued presence of the lesion
that is to be biopsied. The patient should then be
anesthetized according to the previously determined plan. The patient is positioned with their
neck in extension, usually with a rolled towel or
small pillow underneath the shoulder blades [8].
With a high frequency probe (7.5–15 MHz),
the nodule of interest is identified and an overview of the surrounding anatomy is obtained [4].
Using color Doppler, large surrounding vascular
structures are noted. An appropriate path for the
biopsy needle is determined to avoid vascular
structures and traverse as little as normal tissue
as possible. The neck is prepped and draped in
standard sterile fashion. At this point, the ultrasound probe should be covered with a sterile
probe cover containing ultrasound gel.
Although many ultrasound-guided procedures
require the use of ultrasound gel on the outside
of the probe cover in order to maximize image
quality, gel can get stuck in the needle bore and
can interfere with the cytology assessment by
causing precipitation on Wright staining [9]. For
this reason and because the thyroid is a superficial structure, FNA can be performed in an alternative manner using only an antiseptic solution
such as betadine to achieve adequate skin contact
with the ultrasound probe. It should be noted that
ultrasound gel can still be used as long as the operator is aware of the potential downsides.
Because the thyroid gland is highly vascular,
a small gauge needle is recommended for aspiration. There are different recommendations for
the gauge of a needle ranging between 22 and 27
gauge [4, 9, 10, 12]. Any needle gauge less than
27 is too small, given that the diameter of the follicular cell nucleus is in the 200 µm range and
the inside diameter of a 25- and 27-gauge needle
is between 191 and 241 µm [9]. Furthermore,
core biopsies of the thyroid gland are not part of
routine practice and are rarely performed due to
the potential increased risk of bleeding complications.
While operators at many institutions use local
anesthesia, it is not recommended by the National Committee for Clinical Laboratory Standards
because it can cause more pain than the FNA itself. Moreover, it can obscure cellular detail on
pathology and anatomic detail during instillation
[11]. However, local anesthesia does offer the
benefit of pain relief during and after the procedure, allowing for a better patient experience.
Typically, this is done using a 25-gauge needle
and should be used in the subcutaneous fat, not
the reticular dermis, to infiltrate dermal nerves
[9]. The amount of anesthetic that can be administered varies depending upon the type of medication used, whether it is mixed with epinephrine,
and the weight of the patient. Additionally, an
anesthetic cream such as EMLA cream, a spray
formulation or ice can be used as an anesthetic.
The former has a vasoconstrictor effect and leads
to less hemodilution of the aspirate [9, 12].
Under ultrasound guidance, utilizing the free
hand technique or an ultrasound guide, the needle
is slowly advanced toward the superficial margin
of the nodule. Several forward and back oscillations are made with the needle through the lesion
(Fig. 20.6). This motion allows for more material to enter the bore of the needle and become
trapped for extraction. The intralesional dwell
time during this portion of the procedure should
be 2–5 s. Suction can be applied to the needle
with a syringe during the aspiration but is not
necessary as there is already native suction provided by the existing surface tension in the nodule [13, 14]. The literature suggests that suction
is more convenient, however, it is not does not
provide a better diagnostic yield when compared
to using no suction [13, 14].
23320 Fine Needle Aspiration (FNA) of the Thyroid Gland
Fig. 20.6 Intraprocedural transverse ultrasound image
of a thyroid fine needle aspiration. Note the echogenic
25-gauge needle (arrow) within a dominant right thyroid
nodule
Some operators feel more needle passes
through the lesion can increase the diagnostic
yield. However, there is some literature to suggest that more than ten needle passes during
sampling can increase the risk of hematoma
formation [10]. If blood is identified within the
needle during sampling the operator should not
be alarmed, since this only means that the lower-viscosity blood has preferentially entered the
needle over the higher-viscosity material. Blood
identified within the needle can be due to excessive suction or a long dwell time of the needle
within the lesion [9, 11].
The nodule of interest is sampled and the needle is given to the cytopathologist for analysis.
Typically, three to five passes are performed at
the beginning of the procedure and given to the
cytopathologist at one time, since preparation of
the material for viewing under the microscope
can take a few minutes. If no cytopathologist is
present, the needle can be placed bevel down and
the aspirate smeared onto a slide and submitted
to cytopathology [11]. When preparing your own
slides, using a one step method is preferable by
using one slide to hold the sample and the second to spread it. It can be difficult to know when
enough material is present for diagnosis when an
on-site cytopathologist is not present.
A thorough ultrasound of the neck is performed after the procedure to look for a hematoma [10]. An ice pack or acetaminophen is the
preferred method of analgesia post procedure.
Discharge instructions should include notifying the clinician for any signs of neck swelling,
shortness of breath, redness, or discharge from
the FNA site [10].
Post-procedural Complications
Complications that can be seen after a thyroid
FNA include pain, bruising, and hematoma around
the FNA site. Rarely, an infection may be encountered. Allergic reactions to local anesthetics are
rare and the main treatment is antihistamines. The
recurrent laryngeal nerve is within the region of
the thyroid, therefore puncture is possible, however this is extremely rare [11, 15]. Large blood
vessel transgression can occur with the needle,
but with good ultrasound imaging and color Doppler this is also extremely rare. Another rare complication is tumor seeding which has been noted
in 12 cases [16]. Tumor seeding may be prevented
by limiting the number of needle passes, making
sure the needle does not transgress deep to the lesion and using smaller needles for the FNA.
The main cause of inadequate samples is other
substances such as ultrasound gel or blood predominating the sample. This can be minimized
by limiting the use of ultrasound gel or suction
and having on-site cytopathologist to review the
sample. Other causes include performing a biopsy on a predominantly cystic or excessively
vascular nodule. Although studies evaluating the
efficacy of FNA of the thyroid in children are
not well established, many centers find that diagnostic samples can be obtained in over 90 % of
patients. Some authors have concluded that the
efficacy is less for nodules less than 5 mm [17].
Summary
FNA of suspicious thyroid nodules in children
is an important part in the medical evaluation of
these patients. As research continues to evolve,
234 R. Vellody
it is important for clinicians to know what constitutes best practice with respect to technique.
Doing so will allow for maximum yield, less discomfort to the patient, and less inconvenience to
the patient’s family.
References
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and may have an adverse outcome. Clin Thyroidol.
2009;21(10):10–2.
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Cooper D, et al. Revised American thyroid associa-
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nodules and differentiated thyroid cancer. Thyroid.
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Kim M, et al. US-guided fine-needle aspiration of thy-
4.
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5. Frates M. Management of thyroid nodules detected at
US society of radiologists in ultrasound consensus conference statement. Ultrasound Q. 2006;22(4):231–40.
6. Frates M. Management of thyroid nodules detected at
us: society of radiologists in ultrasound consensus conference statement. Radiology
Cibas E, Ali S The
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thyroid cytopathology. Thyroid. 2009;19:1159–1165.
Dhurandhar N, et al. Fine needle aspiration biopsy
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(FNAB) techniques; approved guideline-second edi
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2003;23(27):3.
thyroid nodules in children and
. 2005;237(3):794–800.
bethesda system for reporting
9. Pitman M, et al. Techniques for thyroid FNA:
opsis of the national cancer institute thyroid fine-needle aspiration state of the science conference. Diagn
Cytopathol. 2008;36(6):407–24.
Dogra V, Saad W
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thyroid nodules. In: Ultrasound-guided procedures.
ed. New York: Thieme; 2010. pp. 67–72.
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NCCLS document GP20-A2 [ISBN 1-56238-509-7].
NCCLS, 940 West Valley Road, Suite 1400, Wayne,
Pennsylvania 19087-1898 USA, 2003.
12. Oertel Y. Fine-needle aspiration of the thyroid: technique and terminology. Endocrinol Metab Clin North
Am. 2007;36:737–51.
Pothier D, Narula A. (2006). Should we apply suc-
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systematic review and meta-analysis. Ann R Coll Surg
Engl. 88(7):643–45.
Maurya AK, Mehta A, Mani NS, Nijhawan VS,
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doi:10.4103/0970-9371.70737.
15. Tomoda C, Takamura Y, Ito Y, Miya A, Miyauchi
A. Transient vocal cord paralysis after ne-needle aspiration biopsy of thyroid tumor. Thyroid.
2006;16(7):697–9.
Polyzos S, et al. A systematic review of cases
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biopsy. World J Surg. 2010;34:844–51.
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Diagnostic and Therapeutic Drainage
Samir K. Gadepalli
21
Introduction
There are many different types of collections of
fluid (e.g., those in a cavity, those after surgery,
those that are congenital); the approach to diagnosis or therapy may be different based on the
type and location. Being able to categorize fluid
collections by type and location in the body is the
first step. These fluid collections can occur at any
part of the body and knowing your anatomy is a
key way to avoid any complications.
The next step is preparation which leads to a
series of questions: Do I have all the equipment,
does this need to be sterile, does the primary
team managing the patient want the fluid sent for
special things including cultures, is this a recurrence, do we need to perform a sclerosis, is this in
conjunction with a biopsy, is ultrasound the correct image guidance modality for this instance.
Knowing the history and doing a thorough physical checkup is still important prior to picking up
the ultrasound. A patient with allergies, having
severe anxiety to the procedure, or just after a
meal, could seriously hinder the ability to perform an ultrasound. As interventional ultrasound
is an adjunct to clinical care—the provider caring for the patient and the person performing the
ultrasound-guided procedure may be different—
S. K. Gadepalli ()
Division of Pediatric Surgery, Department of Surgery,
C.S. Mott Children’s Hospital, 1540 East Hospital Drive,
SPC 4211, Ann Arbor, MI 48108, USA
e-mail: samirg@med.umich.edu
© Springer International Publishing Switzerland 2016
S. Scholz, M. D. Jarboe (eds.), Diagnostic and Interventional Ultrasound in Pediatrics
and Pediatric Surgery, DOI 10.1007/978-3-319-21699-7_21
leading to a fragmentation in care that could lead
to communication issues.
Finally, technical considerations, such as having more than one ultrasound probe, are essential. The diagnostic and therapeutic probes used
for ultrasound do not have to be the same. For
example, identifying the collection may be better with a curved probe, but following the needle
into the cavity may be better with a linear probe.
Furthermore, having a range of drainage catheters, guidewires, and dilators is crucial to the success of a drainage procedure. Moreover, the path
to the collection does not have to be directly percutaneous and may need to traverse an organ. For
example, accessing the gallbladder through the
liver parenchyma or a pelvic collection through a
transrectal approach often is superior to other options. Finally, having the ability to inject the collection with contrast and monitoring this using
fluoroscopy should not be underestimated.
In this chapter, we focus on general principles as briefly outlined above, then focus on
a transrectal approach to drainage, after which
we discuss special circumstances where there is
literature to support a specific strategy. For example with ascites, make sure to have albumin
available or know if the patient has significant
liver disease; or with a pleural effusion, use of
tissue plasminogen activator (TPA) to prevent a
recurrence versus needing to send samples to rule
out malignancy.
235
236 S. K. Gadepalli
General Principles
Fluid collections can be differentiated into various types based on history and anatomic location.
Categorizing them based on history and location
helps with management by using a diagnostic or
therapeutic algorithm. The following is an example of various ways a collection can be categorized:
1. Collections in general: unknown, malignant,
infectious, lymphatic
2. Abscesses: postoperative, chest, mediastinal,
abdominal, pelvic
3. Gastrointestinal (GI): pancreatic, splenic,
foregut/duplication, chronic cholecystitis, hydatid cyst
4. Urologic: hydronephrosis, suprapubic catheter placement
Prior to drainage of a collection, the indications must be reviewed, coagulopathy must be
excluded or treated, and the appropriate imaging modality must be chosen [1]. The diagnostic
approach to fluid collections starts with a good
history and location of the lesion. If the patient
has a history of malignancy or risk factors that
increase the risk for a malignancy, the identification of a collection, such as a pleural effusion,
can be a marker of the malignancy. Furthermore,
qualities of a collection, such as the percentage
of solid material, can differentiate a cystic collection. Knowing the likelihood of a malignancy is
important in the approach to drainage of a collection as the tract used to sample the fluid can be a
potential pathway for the spread of the disease.
Similarly, the sampling of the collection can
be diagnostic, therapeutic, or both. Therefore,
having a general framework to approach the fluid
is useful to prevent additional procedures or anesthetics. As there is always a risk in the aspiration of a collection, combining procedures into
one setting can mitigate further risks. For example, injection of a sclerosant into the cavity during drainage of a lymphatic collection prevents
recurrence of the collection and, concomitantly,
an additional procedure.
Drainage of a fluid collection should only be
performed when there is [2]: a suspicion of infec-
tion, a need for fluid characterization, or symp-
toms that warrant drainage. “The basic indication
for needle aspiration is to confirm the radiological diagnosis of an abscess because the radiological signs may not distinguish amongst various
types of fluid collection including abscess, hematoma, urinoma, biloma, lymphocele, seroma,
and loculated ascites. The main indications for
catheter drainage include treatment or palliation
of sepsis associated with an infected fluid collection, and alleviation of the symptoms that may
be caused by fluid collections by virtue of their
size, like pancreatic pseudocele or lymphocele”
[1]. Figure 21.1 demonstrates needle entry into a
fluid collection of unknown etiology for diagnostic purposes.
Informed consent following a thorough discussion with the patient is mandatory for any
invasive procedure. Rarely are the procedures
emergent and the expectations of the patients and
primary-care providers need to be assessed prior
to performing the procedure. Identification of the
indications, approach to drainage, choosing the
appropriate imaging modality, specific diagnostic tests on the drainage, and therapeutic options
should all be discussed at this time.
In diagnostic or therapeutic drainage, the steps
are fairly simple though difficult to execute without sufficient practice. The collection is identified using an ultrasound probe (as mentioned
earlier, the probe used to initially find the collection and that used for targeting drainage may be
different). Using ultrasound guidance, the collec-
Fig. 21.1 Figure represents needle entry into a collection
of unknown etiology using a curved probe for guidance
23721 Diagnostic and Therapeutic Drainage
Fig. 21.2 a Figure represents needle entry into a locu-
lated abscess cavity with multiple septations. b Figure
represents needle connecting multiple loculated collections by breaking up the septations under visualization.
tion is approached using an 18- or 22-gauge entry
needle based on the depth and size of the fluid.
Advancing the needle in line with the ultrasound
transducer provides excellent visualization of the
entire needle and the target collection simultaneously. This improves safety and maneuverability
in advancing the needle. If purulent fluid is aspirated, it is sent for culture; of note, immunocompromised patients may have bacteria or fungal
collections without evidence of an immune response. Keep in mind that a Gram stain may fail
to grow any organisms if the patient has already
received antimicrobial therapy. Furthermore, use
of a needle without the syringe attached can be a
useful technique to facilitate guiding the needle
into the cavity without the added weight of the
syringe. The syringe can be attached once entry
into the cavity can be confirmed by imaging.
Based on the thickness of the fluid, the needle
may need to be “upsized” prior to drainage of the
contents.
To “upsize” the needle, a guidewire can be
inserted with serial dilation over the guidewire
using a Seldinger technique. A 0.010- or 0.018in. wire can be placed through the 22-gauge needle whereas a 0.035 guidewire can be inserted
through an 18-gauge entry needle. When using
larger dilators, we routinely exchange a thinner
guidewire to a larger diameter and stiffer wire to
provide a stiff backbone for the dilator to travel
over preventing dislodgment and errant passage
of the dilator. Furthermore, the needle and guidewire exchange is easier to accomplish with the
cavity filled with fluid as there is more resistance
on the wall to prevent dislodgement as well as
prevent inadvertent entry through the opposite
wall. If the fluid within a cavity has already been
c Figure represents abscess cavity being drained by the
pigtail catheter that is now in place. The abscess is irrigated with saline and collapsed down at the end of the
procedure
evacuated for diagnosis, irrigation with saline
can be used to refill the area and help with the
needle and guidewire exchange. Once a drainage cathether has been inserted into the cavity,
we routinely use ultrasound to confirm adequate
drainage of the cavity and assess for additional
located collections that were not initially noted or
were inadequately drained. Although, the largest
possible drainage catheter is generally used, there
is no difference in recurrence, drainage time, and
complications [3]. Figure 21.2 demonstrates
evacuation of a loculated abscess by breaking up
septations using the needle and placement of a
pigtail for irrigation and drainage.
The management of a drain when placed
should be standard for each institution. Drains
can be placed to bulb or gravity drainage based
on the expected quality and quantity of output.
They should be ideally flushed with saline daily
and removed in about 1–3 days when the output
is less than 10 ml/day or 5 ml/day in infants [2].
While a drain is in place, antibiotics should be
considered if there is a risk of translocation based
on host factors, if there is adjacent foreign material such as an implant, or if the output is presumptively infectious.
Ultrasound has become the imaging modality of choice for many interventions with the
advent of high-resolution, wide-angle probes.
Ultrasound also offers the unique advantages of
portability, immediate availability, and flexibility, owing in part to the wide range of transducers now available. Ultrasound probes have been
specifically designed to guide the biopsy of small
lesions, allow precise control of biopsy instruments, and provide direct, real-time visualization
of successful target lesion biopsies. Moreover,