Differential Diagnosis of
Congenital Neck Masses
Key Points
 The two major categories of neck masses in children are congenital and acquired
lesions. Congenital cysts make up the majority of the congenital lesions, whereas
infectious masses comprise a majority of the acquired ones.
 A good history and physical are essential to narrow the differential diagnosis of a
pediatric neck mass. Computed tomography (CT), magnetic resonance imaging
(MRI), and neck ultrasound are the major radiologic studies that help in the
evaluation of a neck mass.
 Most branchial cleft cysts are either second or third branchial derivatives.
Thyroglossal duct cysts develop within the embryonic thyroid descent tract.
 Hemangiomas are proliferative lesions, rather than neoplastic, and typically begin to
involute at 18 to 24 months of age. Vascular and lymphatic malformations are also
congenital lesions but do not involute.
 Most infectious lymphadenopathy is viral, but streptococcal or staphylococcal
organisms may cause suppurative lymphadenopathy.
 Lymphoma is the most common neck malignancy in children and presents as an
enlarging neck mass with or without systemic symptoms of fever, weight loss, night
sweats, or fatigue. Malignant neck lesions tend to occur most commonly in either the
posterior cervical or supraclavicular regions.
 The presentation of a neck mass in a pediatric patient has many
diagnostic possibilities not normally encountered in an adult (Fig. 198-1).
Neoplastic disease, especially malignant, is the primary consideration in
the evaluation of a neck mass in an adult. In contrast, diagnosis of a
pediatric neck mass can be categorized, depending on the location,
growth factors, and the child’s age. The possibility of malignancy should
always be considered in the differential diagnosis in pediatric patients;
however, it is not as overriding a concern as in adults.
 The two major categories of pediatric neck masses include congenital
and acquired lesions. Congenital masses have a high incidence (>50% in
some series),1 which initially differentiates them from acquired masses.
The primary type of acquired masses is inflammatory (acute and chronic),
which further narrows the differential diagnosis. Benign and malignant
lesions are rare in the pediatric patient.
 The approach to the child with a neck mass depends on the history and
physical examination. Radiographic and laboratory studies may prove
helpful, but some masses require surgical biopsy to establish the
diagnosis. Thus the pediatric neck mass often poses a challenge to the
surgeon.
History
In the evaluation of a pediatric patient with a neck mass, a
detailed history alone can often exclude many lesions in the
differential diagnosis. Consideration of temporal relationships can
often prove helpful. A history of infection elsewhere in the patient
or recent travel or exposure to farm animals may suggest an
infectious origin. Preceding trauma may signal a hematoma,
whereas an increase in the size of the mass or pain with eating
may point to a salivary gland problem. Exposure to drugs such as
phenytoin may also be contributory. The growth characteristics of
the neck mass are important. Slow growth suggests a benign
process, whereas rapid enlargement occurs with infectious or
malignant lesions. Some masses fluctuate in size (e.g.,
hemangiomas increase in size with straining and crying). Fever,
weight loss, night sweats, or fatigue suggest a malignant process.
Physical Examination
In the evaluation of a child with a neck mass, comprehensive head and neck
examination is essential. Clues to the pathogenesis of the neck mass may be
found anywhere in the head. Likewise, a total physical examination should be
performed with special attention to other lymph node groups such as the axillae
and groin. Palpation for an enlarged spleen should always be attempted. Infants
frequently have small palpable lymph nodes in the posterior cervical region,
whereas older children have palpable nodes in the anterior cervical, posterior
cervical, and submandibular regions. Any node greater than 2 cm in diameter
falls outside the range of these normal hyperplastic nodes and should be
evaluated further. In examination of abnormal lymph nodes or a neck mass, the
location is important for determining the site of the precipitating infection or the
primary source of a malignant neoplasm. For example, infection in the
nasopharynx tends to drain into the posterior cervical region, whereas tonsillitis
may cause enlargement in the anterior cervical
region. The consistency of a neck mass is frequently helpful in categorizing
the mass. For example, hard masses tend to occur with infection or a malignant
process. Fixation of a mass to the skin or deeper structures of the neck
suggests a malignancy. A fluctuant mass tends to occur with abscess formation
or a cyst.
Radiologic Studies
Depending on the clinical impression of a neck mass from the history and
physical examination, selected radiographic studies may help narrow the
differential diagnosis. Chest radiography is helpful if a malignancy,
sarcoidosis, or pulmonary tuberculosis is suspected. In the evaluation of the
nasopharynx, cervical spine, or retropharyngeal region, lateral neck
radiography may show an abnormality. Likewise, a sinus series may show
evidence of an infection or neoplasm in the paranasal sinuses. In cases of
infection in the neck, computed tomography (CT) with contrast may
differentiate cellulitis that may respond solely to antibiotic therapy from an
abscess with rim enhancement that may necessitate surgery. CT with
contrast also helps identify vascular masses such as hemangiomas.
Magnetic resonance imaging (MRI) provides even better detail of soft
tissue. When combined with contrast, MRI is also useful in the evaluation of
vascular lesions. Ultrasound of the neck is most helpful in differentiating a
cystic structure from a solid mass. It should be included as part of the
evaluation of any thyroid mass. Before excision of a thyroglossal duct cyst,
ultrasound can confirm the presence of a thyroid gland in its normal
position, ruling out the possibility of ectopic thyroid. Use of ultrasound in
these cases is easier and more economical. Thyroid scanning remains
essential in the evaluation of any thyroid mass.
Laboratory Studies
As with radiography, selected laboratory studies may be useful in
the evaluation of the pediatric neck mass. A complete blood
count with differential is indicated if a malignancy or systemic
infection is suspected.
Serologic testing for Epstein-Barr virus (EBV), cytomegalovirus,
toxoplasmosis, syphilis, or cat-scratch disease may be
diagnostic.
An elevated serum calcium level is highly suggestive of
sarcoidosis, whereas thyroid function studies are necessary in
the evaluation of most thyroid masses.
Urinary collection for vanillylmandelic acid (VMA) is helpful when
neuroblastoma is suspected.
Although not as accurate as a culture of infected tissue, skin
tests, if available, remain a reliable indicator of mycobacterial
disease.
Surgical Diagnosis
Although fine-needle aspiration of a suspected malignancy is
not as reliable in children as in adults, fine-needle aspiration of
a neck infection decompresses the mass and provides
material for culture.
In some cases, especially when the diagnosis of malignancy is
considered, an incisional or excisional biopsy is indicated.
Advantages of a biopsy include inspection of the lesion,
providing a cuff of healthy surrounding tissue and tissue for
frozen and permanent section, electron microscopy, and tumor
markers.
Congenital Masses
Branchial Cleft Cysts
Although the definitive mechanism for the development of branchial cleft cysts is
unclear, it is suspected that these congenital masses result from the cervical sinus of
His becoming entrapped without an external or internal opening. An epithelium-lined
cyst results. Others suggest that these cysts develop from epithelial rests of tissue from
Waldeyer’s ring.4 Branchial cleft cysts are relatively common; in one series, they
comprise one third of congenital neck masses.1
Branchial cleft cysts typically are seen as nontender, fluctuant masses that may become
inflamed and abscess during an upper respiratory infection (Fig. 198-2). First branchial
cleft cysts, although rare, typically present near the angle of the mandible (Fig. 198-3).
Second branchial cysts are found high in the neck and deep to the anterior border of the
sternocleidomastoid muscle. Third branchial cleft cysts, also rare, are seen near the
upper pole of the thyroid gland. Other symptoms, depending on the size of the cyst,
include dysphagia, dyspnea, and stridor.
Radiologic evaluation of a branchial cleft cyst may include ultrasound, CT, and MRI.
Ultrasound shows a fluid-filled cyst and can differentiate cystic lesions from solid
masses. CT and MRI also confirm the cystic characteristics of the mass and, more
importantly, delineate the relationship of the cyst to surrounding structures
(Fig. 198-4).
Management of branchial cleft cysts is surgical excision. It is advisable, if possible, to
manage an infected cyst with antibiotics, allowing the inflammation to resolve before
excision is attempted.
Thyroglossal Duct Cysts
Thyroglossal duct cysts form in a persistent thyroid descent tract that
begins as an elongation of the thyroid diverticulum. Beginning at the
foramen caecum of the tongue, this tract may extend to the thyroid gland
itself, where some tissue may persist in the region of a pyramidal lobe.
These remnants are cysts and are not associated with a cutaneous sinus
or fistula tract unless surgically drained and inadequately excised. They
comprise approximately one third of congenital neck masses in children.1
Most thyroglossal duct cysts are seen in the midline near the level of the
hyoid bone because the tract passes just anterior to the hyoid bone (Fig.
198-5). Some cysts may present laterally and are not infrequently found
superior to the hyoid or as low as the level of the thyroid gland.
Thyroglossal duct cysts that occur off the midline may be difficult to
differentiate from branchial cleft cysts, an important factor in their surgical
excision. Other unusual presentations of thyroglossal duct cysts include
formation on either side of the hyoid bone as dumbbell- shaped lesions
and, rarely, as cystic lesions in the larynx. Thyroid tissue is found in
surgical specimens in up to 45% of cases.5
A thyroglossal duct cyst usually presents as an asymptomatic mass but
may be associated with mild dysphagia. Not infrequently, presentation of
these cysts may be accompanied by infection, causing rapid enlargement
that may produce significant dysphagia and choking.
In cases in which a thyroglossal duct cyst is suspected, it is
important to differentiate ectopic thyroid from a cyst. Although only
10% of ectopic thyroid is found in the neck, it may represent the
only thyroid tissue in 75% of patients.6 Children with ectopic thyroid
may be mildly hypothyroid; however, excision of this tissue
necessitates hormone replacement for the remainder of the
patient’s life. Thyroid ultrasound and radionucleotide scanning can
differentiate ectopic thyroid from a thyroglossal duct cyst;
ultrasound is easier to perform, less expensive, and does not use
radioisotopes.
The Sistrunk operation is the standard method of thyroglossal duct
cyst excision. The cyst is excised along with a cuff of tissue
including the center portion of the hyoid bone. Incision and
drainage of an infected cyst should be avoided because violation of
the cyst capsule may invite recurrence. Recurrence rates of nearly
10% have been reported in children who have undergone
uncomplicated Sistrunk operations.1
Lymphatic Malformations (Lymphangiomas)
The term lymphatic malformation is a better definition of the lesion
that was previously termed lymphangioma. Lymphatic
malformations are congenital malformations of lymph tissue that
result from the failure of lymph spaces to connect to the rest of the
lymphatic system. Lesions containing both lymphatic and venous
components may be labeled combined venolymphatic
malformations. Macrocystic lymphatic malformations (previously
termed cystic hygroma) contain large thickwalled cysts that have
less infiltration of surrounding tissue. Microcystic lymphatic
malformations have more extensive infiltration of the soft tissue
structures of the head and neck, especially in the tongue and floor
of mouth, making their excision difficult.
A lymphatic malformation presents as a soft, smooth, nontender
mass that is compressible and can be transilluminated (Fig. 198-6).
Typically, lymphatic malformations fluctuate in size as a result of
infection or hemorrhage. They mostly impact the cosmetic
appearance of the child. Depending on the size and location of the
mass, there may be respiratory compromise and difficulty in feeding.
Radiographic evaluation with MRI or CT is invaluable for
diagnosis and determination of the extent of the lesion.
Radiography shows fluid-filled spaces with surrounding
connective tissue. Because these malformations lack a capsule
and extend along the lymphatic channels, MRI or CT is essential
in defining normal anatomic structures that should be preserved
when surgical excision is performed.
The goals of surgery are to improve cosmetic appearance and to
counter impaired breathing or eating. Because of the infiltrative
nature of these malformations, complete surgical excision is
often difficult; debulking of the mass often accomplishes these
goals. Some experts recommend staging of surgical excision in
extensive cases.7 Management with radiotherapy has not been
effective.8 Macrocystic lesions can be treated with sclerotherapy
using alcohol. An experimental lyophilized streptococcal
compound, OK-432, has been used successfully to sclerose
macrocystic lesions.9
Hemangiomas
Hemangiomas are proliferative endothelial lesions rather than true
neoplasms. Hemangiomas present at birth, grow rapidly during the first year
of life, and begin to slowly involute at 18 to 24 months of age.
Hemangiomas occur in up to 10% of children with a female-to-male
ratio of 2 : 1.
Hemangiomas are seen as red or bluish soft masses that frequently have a
skin component. Typically, these masses are compressible and increase
with straining or crying. With large hemangiomas, a bruit may be heard over
the lesion. CT or MRI with contrast often confirms the diagnosis of a
vascular lesion (Fig. 198-7).
Because hemangiomas typically involute after several years, the usual
management is observation, unless there is functional impairment, bleeding,
skin necrosis, or a coagulopathy caused by thrombocytopenia.
Use of systemic corticosteroids may be helpful in the management of
complications such as skin ulceration, dysphagia, dyspnea,
thrombocytopenia, or cardiac failure.11-14 Surgical excision or laser therapy
may be helpful in cases of incomplete involution or when mild functional or
cosmetic abnormalities remain. Management with radiotherapy may lead to
malignant transformation, and the use of sclerosing agents and cryotherapy
has produced poor results.8,15
Dermoid Cysts
Similar to teratomas, to which they are pathologically
related, dermoid cysts arise from epithelium that has been
entrapped in tissue during embryogenesis or by traumatic
implantation. Dermoid cysts consist of epithelium-lined
cavities filled with skin appendages (e.g., hair, hair follicles,
sebaceous glands). They are found at other sites in the
head and neck including the orbit, nose, nasopharynx, and
oral cavity.
Typically, dermoid cysts are seen in the midline of the neck,
usually in the submental region (Figs. 198-9 and 198-10).
They are attached to and move with the overlying skin and
are painless unless infected. Management is by complete
surgical excision.
Vascular Malformations
Vascular malformations can be divided into two groups
depending on blood flow. Slow-flow lesions include
capillary malformations and venous malformations,
whereas arterial and arteriovenous malformations are
typically fast-flow lesions. Vascular malformations
represent congenital structural anomalies, grow at the
same rate as the child, and do not involute.
Venous anomalies of the external jugular vein may
occasionally present as a neck mass.21 Typically, the
external jugular vein empties into the subclavian vein, but it
may empty into the internal jugular vein outside the carotid
sheath, forming a venous plexus. Jugular malformations
present as soft, compressible masses along the anterior
border of the sternocleidomastoid muscle. Management is
by ligation or excision of the anomaly.
Sternocleidomastoid Tumors of Infancy
Neonates with sternocleidomastoid tumors present with neck
masses that are usually not apparent at birth but appear at 1 to 8
weeks of age. Pathologically, the mass is characterized by dense
fibrous tissue and the absence of normal striated muscle (Fig. 19811). As the mass resolves, the remaining muscle continues to
degenerate into fibrous tissue. The etiology of this disorder, also
known as congenital torticollis, is unclear; however, birth trauma,
ischemia of the muscle, and intrauterine positioning have been
implicated.
Most patients are firstborn22; siblings are rarely affected.1
Congenital torticollis presents as a firm, painless, discrete, fusiform
mass within the sternocleidomastoid muscle that slowly increases in
size for 2 to 3 months and then slowly regresses for 4 to 8 months
(Fig. 198-12). Because the mass disappears in more than 80% of
cases,23 conservative management with physiotherapy (passive
and active motion) prevents the development of restrictive torticollis.
In resistant cases, surgical section of the sternocleidomastoid
muscle may be required.