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Fig 10.
Axial (A), coronal (B), and sagittal (C) CT images in soft tissue window of a child with cervical extension of a bronchogenic cyst.
The images show a well-defined cystic structure (A-C) in the sternal notch region (C). The predominant volume of the cystic structure is
found in the upper thoracic region (B, C) and therefore the cervical part of the lesion presumably represents cervical extension of a thoracic
bronchogenic cyst.
Fig 11.
Axial T2-weighted (A) and sagittal T1-weighted (B) fetal MR images of a fetus with a large cervical teratoma. The axial image (A)
shows a large right-sided neck lesion with widespread infiltrative extension. The cystic components are T2 hyperintense. The sagittal image
(B) demonstrates the typical area of fat as T1 hyperintense signal intensity (arrow). Polyhydramnios is noted and is due to impaired fetal
swallowing. The postnatal CT image (C) of the child shows the calcification / ossification in the lesion.
three embryonic cell layers involving endodermal, mesoder-
mal, and/or ectodermal elements. They are hypothesized to
arise either from pluripotent stem cells sequestered during em-
bryogenesis or from embryonic tissue that escaped the regional
influences of the primary organizer.
6
Teratomas are classified
as mature or immature lesions.
18,32
The risk of malignant con-
genital cervical teratomas increases with advanced age at di-
agnosis. Alpha-fetoprotein (AFP) is an indicator for teratoma
in infants and children; however, in neonates, AFP has high
normal baseline values. Cervical teratomas typically are lo-
cated in the midline in the suprahyoid region.
1,32
They may
extend into the mediastinum or compress the trachea. If tra-
cheal compression occurs during embryonic development, this
may result in pulmonary hypoplasia. In prenatally identified
lesions, polyhydramnios may be seen secondary to impaired
fetal swallowing.
32
On US, the lesion shows heterogeneous
echogenicity with solid and cystic components. MR imaging
demonstrates the typical areas of fat as T1 hyperintense signal
intensity. The cystic components are T2 hyperintense. Intrale-
sional calcifications can be identified on susceptibility-weighted
MR imaging sequences or on selective CT examinations. At
time of diagnosis, cervical teratomas are often large lesions with
widespread infiltrative extension.
1,5
There are no reliable imag-
ing features to differentiate mature from immature teratomas.
On histology, these lesions tend to be generally benign mature
tumors.
33
Immature cervical teratoma or malignant transforma-
tion is rare.
Congenital and Acquired Vascular Masses
Vascular Malformations
Vascular malformations include several types of anomalies
and are identified in the head and neck region in 1–4% of
the pediatric population. They demonstrate normal endothe-
lial cell turnover and are classified as nonneoplastic lesions
according to the International Society for the Study of Vas-
cular Anomalies (ISSVA) classification system recently up-
dated in 2014 (Table 2), which stems from the early work
of Mulliken and Glowacki.
34
Vascular malformations may
remain stable, grow commensurate to the child, or demon-
strate enlargement after infection, trauma, or endocrine changes
(eg, puberty, pregnancy). Vascular malformations are grouped
based on the predominant anomalous tissue or vessel type
into lymphatic malformations, venous malformations, arteri-
ovenous malformations (AVMs), capillary malformations, and
mixed-type lesions.
35,36
The capillary malformations (previ-
ously named as port wine stain) are rather cutaneous le-
sions than a neck mass, therefore are beyond the scope of
this review.
Lymphatic malformations are the most common congenital
anomalies in the posterior cervical triangle accounting for
75–80% of the cystic lesions in this region, but they can occur in
any of the different neck regions. The majority of these lesions
are present at birth or appear before the age of 2 years as a
soft mass of variable size.
3
Lymphatic malformations can be
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