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

Classification and nomenclature of vascular 
anomalies
Vascular anomalies may be present at birth or arise shortly 
thereafter. Since they are often very apparent, they have 
always made a great impression among the observers who 
have tried to classify them. Obviously, attempts at classifi-
cation have been conditioned by the historical context and 
the methodological trends in vogue at the time of observa-
tion. This has led to a continuous revision and redefinition 
of terms and caused increasing confusion, sometimes with 
fatal results.
From the initial 
descriptive classification
—based above 
all on the external appearance of those lesions which dazzled 
the first observers—some very suggestive terms emerged, 
some of which have extended their influence to the present 
day. For example, a French dermatologist during the early 
nineteenth century used the generic term “angioses” (i.e., 
*
Francesco Esposito 
[e-mail]
1
Radiology Department, Santobono-Pausilipon Children 
Hospital, Naples, Italy
2
Department of Advanced, Biomedical Sciences, University 
“Federico II”, Naples, Italy
3
Radiology Department, Antonio Cardarelli Hospital, Naples, 
Italy
4
Department of Woman, Child and of General and Specialized 
Surgery, University “Luigi Vanvitelli”, Naples, Italy
5
Radiology Department, Regional Hospital of Bolzano, 
Bolzano, Italy
6
Department of Imaging, IRCCS Bambino Gesù Children’s 
Hospital, Rome, Italy

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14
Journal of Ultrasound (2019) 22:13–25
1 3
affection of the vascular system) to describe a variety of 
acquired and congenital lesions, as well as the term “haema-
toncus tuberosus” (“tumor of the blood similar to a potato”) 
[
1
, 
2
].
Next came 
anatomopathological classification
, under 
which Virchow, considered the father of the cellular pathol-
ogy, in 1863 generally classified all vascular anomalies as 
“angiomas”, labeling them according to vascular architec-
ture (e.g., “angioma simplex”, “angioma racemosum”, and 
“angioma cavernosus”) [
1
, 
3
].
Beginning in the early 1900s, 
embryological classifica-
tion
became widespread. One of the leading figures of this 
system was the Italian Edmondo Malan. In his monumental 
monograph, Malan divides angiomas into “venous,” “trun-
cular”, “arteriovenous”, and “capillary” [
1
, 
4
]. Although 
conceptually interesting, classification on an embryological 
basis does not appear clinically useful, as it fails to differ-
entiate between involutive lesions and non-involutive ones.
Finally, on the basis of clinical-histological studies, in 
1982 Mulliken and Glowacki proposed a 
biological clas-
sification
that distinguishes lesions based on the behavior of 
endothelial cells, with lesions broadly classified as 
heman-
giomas
(lesions in which endothelial hyperproliferation 
is present) and 
malformations
(lesions presenting normal 
turnover of endothelial cells) [
5
].
This fundamental distinction remains the basis of modern 
classification today. In fact, it was adopted and appropri-
ately modified by the International Society for the Study 
of Vascular Anomalies (ISSVA) in 1996 to provide the 
medical community with a universal scientific language that 
would prevent both misdiagnosis and inaccurate manage-
ment. Following adoption, the classification was reviewed 
in 2014 and updated in 2018 [
6
]. Under this classification, 
the vascular anomalies are divided into two main groups: 
vascular tumors
, characterized by a clonal proliferation of 
endothelial cells, and 
vascular malformations
, determined 
by errors in different developmental stages of embryogenesis 
but with a normal endothelial cell turnover. Vascular tumors 
are divided into three groups in relation to their neoplastic 
aggressiveness. Vascular malformations are divided into four 
groups in relation to the vascular structures involved.