Locally aggressive tumors Kaposiform Hemangioendothelioma (and Tufted Angi- oma) Although
Tufted angioma is categorized as a benign
tumor while the
Kaposiform hemangioendothelioma is con-
sidered a locally aggressive tumor [
32
], the two lesions are
treated together because they have many similar aspects.
Both forms may be associated with systemic complica-
tions such as the Kasabach–Merritt phenomenon (char-
acterized by thrombocytopenia, microangiopathic hemo-
lytic anemia, and consumption of coagulation factors).
This common behavior led to the hypothesis that the two
lesions may represent a spectrum of the same neoplasm
[
13
]. The finding of the Kasabach–Merritt phenomenon is
indicative of the presence of one of these two tumors [
9
].
On the US examination these lesions tend to be inho-
mogeneous with poorly defined margins compared to the
surrounding tissues [
11
,
33
–
37
] (Fig.
10
). Tufted angioma
is generally more superficial, usually surrounded by sub-
cutaneous fat, with a maximum thickness of 1 cm [
9
,
33
],
while the Kaposiform hemangioendothelioma is generally
deeper, involving the underlying soft tissues. In addition,
there are sometimes calcifications that are not present in
the Tufted angioma. Although some authors report that
the Kaposiform hemangioendothelioma shows a lower
vascular density than infantile hemangioma [
33
], others
argue that the color Doppler shows a high vascular den-
sity with the presence of vessels already recognizable at
B-mode [
9
,
38
] (Fig.
11
).
Malignant tumors Angiosarcoma The angiosarcoma is an extremely rare
tumor. Only 2% of vascular tumors are malignant, and
angiosarcoma accounts for 0.5% of all pediatric sarcomas
[
13
]. It is a lesion more frequently localized to the limbs. At
the moment there are no pediatric ultrasound reports of soft
tissue angiosarcoma [
9
].
