Infantile hemangiomas are the most common vascular tumors in children, with an incidence of between 4% and 10%.11 They occur more frequently in white girls and most are sporadic. In general, they are not present at birth and progress in 3 characteristic phases. The first is a proliferative phase that lasts for the first 6 months of life, followed by a stabilization phase during the first year. Finally, there is an involuting phase that lasts until 5 to 7 years of age.

These are benign lesions with a favorable outcome and most do not require treatment. However, in 10% of cases, complications may occur, such as ulceration and life-threatening functional alterations, for example airway hemangiomas.

In these cases, propranolol, a nonselective β-blocker, has become the treatment of choice.12 The mechanisms of action that have been proposed include vasoconstriction, angiogenesis inhibition, and endothelial cell apoptosis.13

In general, diagnosis of infantile hemangiomas is clinical, but occasionally, due to the site or involvement of vital structures, complementary studies such as ultrasound imaging, computed tomography (CT), or magnetic resonance imaging (MRI) are required.14

Both CT and MRI generate anatomical information such as exact delimitation of the borders and size and determination of the proximity to adjacent structures. However, these techniques have certain drawbacks such as the need for sedation in children or the need for contrast agents that emit radiation, not to mention the high cost. CT is a reliable method for assessing bone and erosive structures. MRI is considered the method of choice for the study of cervicofacial hemangiomas to rule out posterior fossa malformations–hemangiomas–arterial anomalies–cardiac defects–eye abnormalities–sternal cleft and supraumbilical raphe syndrome (commonly known as PHACES syndrome).15

Ultrasound imaging is a noninvasive method that can be performed in an outpatient setting. The study provides immediate results and sedation is not required, although some authors are including sedation with chloral hydrate in their daily practice to reduce artifacts when performing the Doppler study.16,17 Spierer et al.18 established diagnosis in 20 patients with periorbital infantile hemangiomas without resorting to other imaging studies. The authors considered the technique the method of choice for detecting infantile hemangiomas in children.

Ultrasound imaging is currently the method of choice for assessing infantile hemangiomas because the technique allows measurement of the size, thickness, internal characteristics, and vascularization of the lesion, while involvement of adjacent anatomical structures can also be assessed.18

Infantile hemangiomas have different ultrasound patterns (Table 2), depending on the clinical phase. In the proliferative phase, in B mode, a well-defined solid, hypoechoic tumor mass is observed with a lobulated, homogeneous stroma. The color Doppler image is characterized by hypervascular lesions, with a vessel density>5 vessels/cm2 and a systolic Doppler shift >2kHz and a low resistive index (RI).19

In the involuting phase, however, the hypervascularized stroma of the proliferative phase is replaced by fibroadipose tissue, thereby changing the echogenicity, with most lesions now being hyperechoic and heterogenous. In most cases, there is a decrease in color Doppler flow, but high systolic flow may persist compared with normal skin.

Treatment with propranolol is effective in all growth phases of infantile hemangioma, but it is more effective if treatment is started during the proliferative phase. Bingham et al.20 reported the effectiveness of propranolol in 24 patients. At the end of treatment, a decrease in the size of infantile hemangioma was observed in 70% when treatment was given in the proliferative phase, whereas the reduction was 30% when treatment was given in the involuting phase.

Recent publications describe cutaneous ultrasound imaging as the method of choice for the objective assessment of treatment efficacy with propranolol in complex cases of infantile hemangioma (Fig. 3).21 Sans et al.19 used ultrasound imaging to assess the maximum thickness of infantile hemangioma and RI at baseline and after 60 days of treatment. They observed a decrease in the thickness associated with increased RI.21,22

Figure 3.

Infantile hemangioma on the right nostril treated with propanolol (courtesy of Dr. E. Baselga). A, Lesion prior to treatment. B, Echo Doppler image of hemangioma in proliferative phase; note the abundant vascularization. C, Clinical improvement of the nasal hemangioma. D, Decreased vascularization and thickness of the lesion.

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In general, the minimum duration of treatment with propranolol should be at least 6 months to avoid regrowth of the tumor mass.23,24

Shi et al.17 assessed the ultrasound characteristics of each phase of infantile hemangioma to decide when to suspend treatment with propranolol. The assessments were carried out at baseline, at 3 months, and at 6 months of treatment. Treatment was suspended at 6 months if internal flow was no longer observed or if flow was normal. If flow was still present, treatment continued until flow signals disappeared or after 11 months of treatment, whichever came sooner.

Chang et al.25 reported a more extensive study of 679 children, in which lesion thickness was also used as the endpoint to decide on discontinuation of treatment. The authors discontinued treatment when the color Doppler evaluation had remained stable for 2 months.

Vascular malformations are a group of uncommon diseases that affect 0.5% of the population. They arise due to innate errors in embryonic development of blood vessels.

Venous malformations are lesions formed from anomalous veins. These lesions have differing degrees of communication with adjacent veins.

Clinically, they present as bluish, soft, depressible tumor masses at a similar temperature to the rest of skin. They increase in size during Valsalva maneuvers. The can occur at any site, with the most frequent being the limbs, head, and neck. Although they are generally asymptomatic, during development, complications such as inflammation and thrombotic episodes may occur.26

Venous malformations are typically solitary lesions, but they can appear in multiple cutaneous and visceral forms. The presence of multifocal venous malformations is suggestive of a hereditary disorder or syndrome. Anomalies of the deep venous system are present in 47% of patients with very extensive venous malformations of the limbs and with Klippel-Trenaunay syndrome. Such findings require study of the deep venous system before initiating treatment.27

Venous malformations typically present as anechoic or hypoechoic structures in B mode. Typically, venous malformations have scant fibrous stroma, but the walls of the isolated cavities range from very fine to very thick septa, and so up to 80% of these lesions have a mixed pattern of hypoechogenic cavities and hyperechogenic septa (Fig. 4),28 with the occasional presence of phleboliths.

Figure 4.

Venous malformation. A, Clinical appearance. B, Lesion X flow. Hyperechoic channels are apparent in the dermal-subdermal junction. This ultrasound mode can visualize very slow flows.

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At times, venous malformations are filled with thrombotic material. In these cases, the ultrasound image appears as a soft tissue tumor with mixed echogenicity, making it difficult to differentiate between hemangiomas and other soft tissue tumors (Table 3).29

In color Doppler mode, venous malformations have low and slow flows which are more marked with Valsalva maneuvers or compression-decompression. Venous malformations usually have a venous phasic spectrum with no arterial or arterialized venous flows within; these are more characteristic of arteriovenous malformations.

In ultrasound imaging, the capillary malformations appear as hypoechoic dermal areas with limited features in B mode (Fig. 5). In Doppler mode, an increase in Doppler flow may appear within the lesion compared to the adjacent dermis (Table 4).32

Figure 5.

Capillary malformation. A, Clinical appearance. B, Color Doppler ultrasound. A hyperechoic area can be seen in the dermis with increased vascularization at focal points.

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Troilius et al.32 presented a study in which 55 patients with port wine stains were assessed by ultrasound imaging. The objective of that study was to assess the depth of the capillary malformation and correlate this with response to treatment with pulsed dye laser, the treatment of choice in these patients.

Given that pulsed dye laser penetrates to a depth of around 0.65mm, the thickness of the capillary malformation may be predictive of response.5

Of the syndromes associated with capillary malformations, dominant autosomal syndromes arising from RAS/MAPK mutations are of particular interest.33 These syndromes have been linked to multifocal cutaneous capillary malformations associated with vascular malformations and arteriovenous fistulas in other territories.34

Kim et al.31 have recently described the presence of arterial flow in the capillary malformations detected by echo Doppler imaging, and they put forward the hypothesis that they could be a manifestation of an underlying atriovenous malformation.

Lymphatic malformations have been reported in individuals with RASA-1 mutations. In this case, cutaneous ultrasound could also be useful for diagnosis.34,35

Lymphatic malformations have a very characteristic morphology. They are comprised of cystic cavities with shared hyperechoic walls. The material inside the lesion is anechoic, unless an intralesional hemorrhage has occurred. In this case, we can observe hyperechoic content with hyperechoic signals inside the lesion (Table 5).

From the hemodynamic point of view, in general, lymphatic malformations do not have Doppler flow and, if observed, this is usually present at the walls (Fig. 6).

Figure 6.

Lymphatic malformation. Color Doppler ultrasound Hyperechoic cystic areas can be seen with no blood flow within the lesion. The vessels are located in the walls of the malformation (arrow).

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Differential diagnosis should be established with other low-flow vascular anomalies, which can present a similar appearance in the ultrasound study. In these cases, other methods such as MRI are needed for complete anatomical characterization and to determine the involvement of other structures.

The most widely used treatment for this type of malformation is sclerotherapy with agents such as tetracyclines or ethanol. These procedures are usually guided by ultrasound and fluoroscopic imaging.37,38

Ultrasound imaging is the first complementary diagnostic method in these types of lesions.38 In B mode, we observe tortuous, dilated and poorly defined vessels which, unlike those of hemangiomas, do not have the appearance of a tumor mass (Fig. 7).36

Figure 7.

Arteriovenous atrial malformation. A, Clinical appearance. B, Doppler ultrasound image of the lesion. Subdermal sponge-like areas with increased blood flow. C, Arteriography where arteriovenous malformations can be observed (arrow).

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The Doppler study reveals vessels with high flow that are not usually observed in venous and lymphatic malformations (Table 6).

The technique that best enables us to visualize arteriovenous malformations is contrast-enhanced MRI. However, sometimes this technique may not permit venous drainage to be assessed and arteriography is necessary.37

Kaposiform hemangioendothelioma and tufted angiomas appear to lie at the ends of the same tumor spectrum, with tufted hemangioma the surface variant and kaposiform hemangioendothelioma the deeper version.39

In view of their proliferative capacity, they can cause arteriovenous fistulas that may lead to vascular entrapment phenomena with hemolytic anemia, platelet destruction, and disseminated intravascular coagulation (Kasabach-Merritt phenomenon).40

In ultrasound imaging, high-flow hyperechoic lesions with a solid appearance have been reported in cases with cutaneous or mucosal expression.41

The presence of arteriovenous fistulas in these lesions is not necessarily associated with the presence of the Kasabach-Merritt phenomenon,42 as demonstrated in the series of 9 cases from the General Hospital in Valencia, Spain. Although arteriovenous fistulas were present in several of their cases, this phenomenon was not observed in any of them.

The ultrasound imaging reports of angiosarcomas refer to mammary lesions,43 which are rarely present in primary cutaneous angiosarcomas. The mammary variant of angiosarcoma has variable ultrasound characteristics and can appear either as hyperechoic lesions with lobulated borders or, less frequently, as lesions with mixed echogenicity with hyperechoic areas and irregular borders.44