Pedi Neck Masses and Vascular Anomalies Flashcards
What is the differential diagnosis for a congenital
neck mass?
Lateral neck masses: ● Branchial anomaly ● Laryngocele ● Thymic cyst ● Pseudotumor of infancy Midline neck masses: ● Thyroglossal duct cyst (most common midline congenital neck mass) ● Dermoid cyst ● Plunging ranula ● Teratoma Entire neck: ● Hemangioma ● Lymphatic malformation
What congenital neck mass is most commonly
seen in the first 5 years of life as a 1- to 4-cm
midline cystic mass that moves cranially with
tongue protrusion or swallowing and arises from
the foramen cecum?
Thyroglossal duct cyst
Where in the neck are thyroglossal duct cysts
found?
About 60% are located adjacent to the hyoid bone, 24% are
between the hyoid bone and base of the tongue, 13% are
between the hyoid and pyramidal lobe of the thyroid gland,
and the remaining 3% are intralingual. Up to 20% of cysts
are slightly off the midline, with a predilection for the left.
What is the cause of thyroglossal duct cysts?
Thyroglossal duct cysts form as a persistent epithelial tract
during the descent of the thyroid from the foramen cecum
in the base of the tongue to its final position in the anterior
neck. They rarely undergo neoplastic transformation (1%).
Discuss the evaluation of a child in whom a
thyroglossal duct cyst is suspected.
Evaluate for the presence of thyroid tissue in the cyst (45%)
and whether there is functional tissue elsewhere:
● Ultrasound: Median ectopic thyroid tissue would appear
solid on ultrasound.
● Thyroid function tests: Patients with median ectopic
thyroid tissue are frequently hypothyroid, with elevated
thyroid-stimulating hormone (TSH) levels and resultant
hypertrophy of the ectopic thyroid tissue.
● Thyroid scintiscan: This test is performed if the preceding
tests indicate the presence of a median ectopic thyroid to
determine whether there is functional thyroid tissue in
the cyst and elsewhere.
What is the procedure for removal of a
thyroglossal duct cyst?
Sistrunk procedure: Stresses removal of the central portion
of the hyoid bone associated with the thyroglossal duct
tract to decrease the risk of recurrence and removal of the
tract to the level of the base of tongue.
What is the clinical presentation of a cervical
thymic cyst?
Most occur in the first decade of life as a lateral neck mass,
anterior to the SCM, most commonly to the left; 80 to 90%
are asymptomatic. However, they may enlarge because of
hemorrhage or infection and cause dysphagia, pain,
dysphonia, and dyspnea. They are also known to expand
with the Valsalva maneuver.
What are the possible causes of a cervical thymic
cyst?
● Incomplete descent of the thymus into the chest
● Sequestration of thymic tissue foci along the descent
path into the chest
● Failure of the thymopharyngeal duct to involute
What is the difference between congenital and
acquired thymic cysts?
● Congenital: These cysts are usually unilobular and
originate from persistent rudiments of the thymopha-
ryngeal duct. They may have epithelium derived from the
thyroid and parathyroid glands because of their close
association during development.
● Acquired: Cysts are multilobular and develop from
degenerated Hassall corpuscles (degenerated epithelial
cells); they are associated with Sjogren syndrome,
apalastic anemia, and acquired immunodeficiency
syndrome (AIDS).
What congenital neck mass is a germ cell tumor
made up of ectodermal and mesodermal
elements but has no endodermal elements?
A dermoid cyst, which can contain hair follicles, smooth
muscle, fibroadipose tissue, and sebaceous glands
Where do dermoid cysts form?
Along the lines of embryonic fusion
How are head and neck dermoid cysts
categorized?
They are categorized by location:
● Periorbital region: Most common in the head and neck;
develop along the naso-optic groove between the
maxillary and mandibular processes
● Nasal dorsum: Develop during ossification of the fronto-
nasal plate
● Submentum/floor of mouth: Region of fusion of the first
and second branchial arches in the midline, most
common location in the neck
● Suprasternal, thyroidal, and suboccipital regions
On clinical examination, how can dermoid cysts
be differentiated from thyroglossal duct cysts?
Both most commonly present as painless midline neck
masses. Because of their superficial location and lack of
mesodermal attachments, dermoid cysts do not move with
tongue protrusion or swallowing. Infection of dermoid cysts
is also rare because they have no communication with the
oropharynx.
What is the treatment for dermoid cysts?
Surgical excision. If cervical and cannot exclude the
presence of a thyroglossal duct cyst, consider a Sistrunk
procedure.
What congenital anomaly arises from embryonic
germinal epithelium of all three types: ectoderm,
mesoderm, and endoderm?
Teratoma
What prenatal findings may indicate a cervical
teratoma?
Maternal polyhydramnios: Often diagnosed during the
prenatal or early neonatal period
Where do teratomas occur within the head
and neck?
Neck (most common), nasopharynx, oropharynx, and oral
cavity
What is the EXIT procedure?
The ex utero intrapartum treatment (EXIT) procedure is a
technique used to establish an airway in neonates with
airway compression from congenital anomalies diagnosed
prenatally. It involves establishing an airway while the
fetoplacental circulation is preserved. The fetus is partially
delivered via a cesarean section, and the airway is then
secured while the fetus remains attached by its umbilical
cord to the placenta.
What abnormal dilation or herniation of the
saccule of the larynx can result in an air- (most
often), mucus-, or pus-filled congenital neck
mass, respectively?
Laryngocele, laryngomucocele, laryngopyocele, respectively
What is the difference between an internal and
external laryngocele?
● Internal: Dilation lies within the limits of the thyroid
cartilage and is seen as cystic swelling of the aryepiglottic
fold.
● External: Dilation extends beyond the thyroid cartilage in
a cephalad direction to protrude through the thyrohyoid
membrane.
● Combination: These can have internal and external
components.
What benign congenital neck mass presents as
a firm, round, nontender mass seen at the
junction of the upper and middle third of the
SCM that typically presents 2 to 3 weeks
after birth?
Pseudotumor of infancy. Also called sternocleidomastoid
tumor of infancy, fibromatosis coli, or congenital muscular
torticollis.
What is the natural history of a pseudotumor of
infancy?
It is present 2 to 3 weeks after birth, slowly increases in size
for 2 to 3 months, and then slowly regresses for 4–8
months; 80 to 100% completely resolve by 12 months.
Some benefit is derived from physical therapy.
What salivary gland is most commonly associated
with a plunging ranula?
Sublingual gland
How do plunging ranulae most often manifest?
Intraoral component appears as a blue dome-shaped lesion
in the floor of mouth, usually on either side of the midline.
The extraoral portion is seen as a submental mass
extending along the inferior border of one side of the
mandible. It is not a true cyst.
