Classification and ultrasound findings of vascular anomalies in pediatric age: the essential

Imaging techniques
The first level examination of pediatric vascular anomalies 
is ultrasound (US). The predominantly superficial loca-
tion allows a morphological evaluation of the lesions and a 
dynamic examination of the vascularization. The subsequent 
integration with magnetic resonance is reserved for selected 
cases and is always a next step compared to the ultrasound 
examination.
However, the instrumental investigation cannot be 
separated from a first clinical evaluation. Some elements 
must be known by the radiologist or sonographer who per-
forms the examination to better interpret the findings of the 
investigation:
• 
When was the lesion first noticed?
• 
Was it already present at birth or did it develop later?
• 
What was its growth rate?
The role of ultrasound imaging is fundamental in diag-
nostic orientation and to address the subsequent therapeutic 
phase. The main elements that the ultrasound examination 
must look for are:
• 
the anatomical localization of the lesion by determining 
the involved layers (e.g., skin, subcutis, muscular layer).
• 
degree of compressibility of the lesion (a hard, non-com-
pressible lesion must always be suspicious of possible 
different nature).
• 
distribution and density of vascularization of the lesion, 
including recognition of the type of vessels (arterial or 
venous) involved.
• 
assessment whether the clinically detectable lesion is 
single or consisting of multifocal elements.
The ultrasound examination, however, has intrinsic limits. 
For example, it cannot clearly define the limits in the case of 
very extensive and particularly deep lesions, and it presents 
difficulties in exploring some areas such as those near bony 
and air-filled structures.
Despite the numerous information that the ultrasound 
examination can provide, it is not always possible to arrive 
at a precise diagnosis with the color Doppler exam alone. 
The great semeiological overlap does not always allow for 
a differential diagnosis, not only between different vascular 
anomalies but also with other benign or malignant lesions 
of the soft tissues. In these cases, it is mandatory to use the 
MRI and, if necessary, the biopsy examination.
Vascular tumors
Vascular tumors are divided into three main categories 
according to their nature: benign, locally aggressive, and 
malignant.
Malignant tumors are, fortunately, infrequent among 
pediatric patients. Given the large number of recognized 
lesions, we will cover in particular those most frequently 
encountered in clinical practice. Benign tumors include:
• 
Infantile hemangioma.
• 
Congenital hemangioma (RICH, NICH, PICH).

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Journal of Ultrasound (2019) 22:13–25 
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Although they are identified with the same term (heman-
gioma), these two lesions have two substantial differences, 
one from the clinical point of view and the other from the 
histopathological point of view:
• 
Infantile hemangioma occurs and develops only after 
birth, while congenital hemangioma (as the name sug-
gests) is already fully developed at birth.
• 
From the histopathological point of view, the lesions 
are characterized by different behavior of the glucose 
transporter 1 (GLUT 1) protein. Infantile hemangioma 
is GLUT 1 + , while congenital hemangioma is GLUT 
1 − (this behavior is common with vascular malforma-
tions) [
7
, 
8
].