Vascular soft-tissue tumors in infancy: distinguishing features on Doppler sonography

Soft tissue vascular tumor-like lesions in adults: imaging and pathological analysis pitfalls per ISSVA classification

OBJECTIVES

To compare the magnetic resonance imaging (MRI) and Doppler ultrasound (DUS) findings with the pathological findings of soft tissue vascular tumors (STVTs) according to the 2018 ISSVA (International Society for the Study of Vascular Anomalies) classification to differentiate vascular tumors from vascular malformations.

METHODS

This retrospective study included patients with STVTs who underwent contrast-enhanced MRI and pathological analysis at our hospital between 2010 and 2020. The presumptive diagnosis based on the on-site imaging and histological analysis was compared with imaging and histological analysis conducted off-site utilizing the ISSVA criteria.

RESULTS

This study included 31 patients with 31 vascular tumors located in the head and neck (n = 3), trunk (n = 2), and extremities (n = 26). The off-site pathological analysis confirmed benign vascular tumors in 54.8% of cases (non-involuting congenital hemangioma: 35.5%; epithelioid hemangioma: 13%; pyogenic granuloma: 3%; and spindle cell hemangioma: 3%). Based on the off-site histological analysis, 25.8% were reclassified as having a vascular malformation whereas three had other benign lesions. Only phleboliths were associated with a vascular malformation (p = 0.03). The concordance between off-site MRI and pathological findings was fair (k = 0.3902 (0.0531-0.7274)), whereas that between on-site and off-site pathological analyses was poor (k = -0.0949 (-0.4661 to 0.2763)).

CONCLUSION

Benign vascular tumors have non-specific imaging features on imaging with some overlap with atypical vascular malformations. Therefore, histological analysis is recommended. Imaging and pathological analyses should be performed in accordance with the ISSVA classification to minimize inter-observer discrepancies.

CRITICAL RELEVANCE STATEMENT

Imaging features of benign vascular tumors on MRI are non-specific, leading to discrepancies with pathological findings and potential overlap with atypical vascular malformations. Imaging and histological analyses should be performed in accordance with ISSVA guidelines to improve patient management.

KEY POINTS

The imaging features of benign vascular tumors are non-specific. Histological analysis is recommended for soft tissue vascular tumors in adults. Analyses of soft tissue vascular tumors should be performed in accordance with ISSVA guidelines.

Subcutaneous fat necrosis of the newborn: a pictorial essay of an under-recognized entity

Subcutaneous fat necrosis of the newborn is a self-limited disorder predominantly affecting full-term and post-term neonates during the first 6 weeks after birth. Subcutaneous fat necrosis can be focal or multifocal and affect one or both sides with a predilection for areas of pressure in certain anatomical areas. Subcutaneous fat necrosis of the newborn is associated with perinatal asphyxia and other neonatal and maternal risk factors. Subcutaneous fat necrosis of the newborn presents as a self-limited area of dermal edema followed by indurated subcutaneous plaques, or nontender and mobile nodules, sometimes with skin discoloration [1-3]. The diagnosis is based on the child's history and physical examination, but when in doubt, imaging is helpful. US is the imaging modality of choice to confirm the diagnosis of subcutaneous fat necrosis of the newborn because it provides the best resolution of superficial lesions, requires no sedation and lacks ionizing radiation. US can also help evaluate and characterize other pathologies affecting the superficial subcutaneous soft tissues at this age. Familiarity with subcutaneous fat necrosis of the newborn is important to make a prompt and precise diagnosis and avoid unnecessary imaging tests or invasive procedures.

Musculoskeletal Soft-tissue Masses

Evaluation of soft-tissue masses has become a common clinical practice indication for imaging with both ultrasound and MR imaging. We illustrate the ultrasonography and MR imaging appearances of soft-tissue masses based on the various categories, updates, and reclassifications of the 2020 World Health Organization classification.

Neonatal vascular anomalies manifesting as soft-tissue masses

The broad and heterogeneous spectrum of vascular anomalies ranges from an innocuous localized cutaneous discoloration to complex, extensive and life-threatening diagnoses. While many of these lesions are present at birth, smaller and deeper lesions might be clinically occult for months or years. Certain vascular anomalies commonly manifest in the prenatal or neonatal period and often have suggestive clinical and imaging features that can aid the radiologist in making a correct diagnosis. The characteristics of such lesions presenting very early in life, particularly those manifesting as soft-tissue masses, are the focus of this review.

Color Doppler Evaluation of Arterial Resistive Index in Infantile Hemangioma: A Useful Parameter to Monitor the Response to Oral Propranolol?

Infantile hemangioma (IH) is the most common benign vascular tumor in childhood. In more than 85% of all cases, IHs undergo spontaneous involution, but nearly 10-12% of IHs develop complications and require immediate therapy. Oral propranolol is currently the first-line treatment for IHs. Color Doppler ultrasound is the gold standard in the diagnosis of deep IH, and it is used to evaluate the morphological change and the modification of vascularization that occur during its evolution and treatment. To date, only few data in the literature described the changes of intralesional arterial resistive index (RI) during treatment with propranolol; particularly, some authors have shown an increase of intralesional arterial RI in IHs with clinical regression during treatment with propranolol. The objective of this paper is to evaluate the changes of RI of the intralesional arteries of the IHs during the treatment with oral propranolol. We retrospectively analyzed a total of 64 IHs in 60 patients treated with oral propranolol with a good clinical response. Gray-scale ultrasonography and color Doppler imaging were performed before and during the therapy. The intralesional RIs were measured before and during the treatment. For each lesion, we recorded the RI values, and then we calculated the mean RI value for any single lesion. We compared the mean RI value observed at the baseline with the mean RI value of the last detectable sampling at color Doppler. We also compared between them the mean RI values observed during intermediate ultrasound. The RI values were compared in 44 lesions, with at least two significant samplings of RI. In the 44 lesions compared, we did not find statistically significant variations in the mean RI values between the baseline control and the values recorded at the last post-treatment control. The time trend of mean RI values of the intermediate color Doppler analysis performed between the first pre-treatment control and the last measurable control did not show any statistically significant variation in the trend of mean RI values. Contrarily to what has been described by some authors, in our experience, we have not observed an increase of RI in IHs treated with oral propranolol.

Ultrasonography and magnetic resonance imaging features of kaposiform hemangioendothelioma and tufted angioma

Kaposiform hemangioendothelioma (KHE) and tufted angioma (TA) primarily occurring in infants are difficult to distinguish. This study evaluated ultrasonography (US) and magnetic resonance imaging (MRI) features of KHE and TA. Pathologically proven TA (n = 21) and KHE (n = 40 [11 KHE + Kasabach-Merritt phenomenon [KMP]]) occurring between January 2015 and December 2017 were reviewed. US (n = 61) and MRI (n = 50) findings were retrospectively evaluated. On US, KHE and TA lesions were subcutaneous, while 40% of KHE exhibited an infiltrative pattern extending into adjacent muscles. Of TA lesions, 42.9% were hyperechoic and 96.15% of KHE lesions exhibited mixed echogenicity. Of TA lesions, 76.2% exhibited well-defined margins and all KHE lesions exhibited ill-defined margins. The depth and vascular density of KHE and KHE + KMP were significantly increased compared with TA. The arterial peak systolic blood flow velocity of KHE + KMP was significantly higher than that in TA and KHE. KHE and KHE + KMP were significantly harder than TA on elastography. 3-D color Doppler revealed branch-shape blood flow for KHE and KHE + KMP lesions; for TA, it revealed a dot-like and striped pattern. Considering MRI findings, KHE and KHE + KMP were more likely to exhibit diffuse heterogeneous enhancement after contrast than TA. KHE was infiltrative and more likely to be thick, hypoechoic, ill-defined, richly vascular and hard than TA on US. KHE lesions were subcutaneous and reticular, with heterogeneous enhancement on MRI. Awareness of these features should prompt radiologists in the differential diagnosis of pediatric masses.

Abnormal hemostasis in children with vascular anomalies, part I: Thrombocytopenias among different vascular anomalies

Long before the classification of vascular anomalies from the International Society for the Study of Vascular Anomalies (ISSVA) provided a framework to differentiate vascular anomalies, otherwise known as vascular birthmarks, it was recognized that patients with such lesions can present with acute life-threatening hemostatic and/or thrombotic complications, as well as chronic long-standing bleeding or thrombotic issues. Scenarios such as a rapidly growing vascular lesion with severe acute thrombocytopenia, a visceral hemorrhagic lesion, a lesion associated with repetitive and painful superficial thrombosis, and cases of unprovoked or post-procedural fatal pulmonary embolism highlight the wide spectrum of manifestations of abnormal coagulation in patients with vascular anomalies. The separation of vascular anomalies into two distinct groups, vascular tumors and vascular malformations, was followed by the characterization that their respective coagulopathies were due to either a derangement of platelets or to a disequilibrium of the patient's coagulation/fibrinolytic process. This configuration of coagulopathies will be the foundation for this two-chapter review series. In the initial review, coagulopathies where thrombocytopenia is the main feature will be characterized, whereas the second review will focus on vascular malformations that have a coagulation disorder secondary to some degree of coagulation consumption and/or fibrinolytic pathway derangement.

High-Frequency Ultrasound Investigation of Port-Wine Stains: Hemodynamic Features Revealed By 10- and 22-MHz Transducers

OBJECTIVES

The hemodynamics of the ultrasound (US) features of port-wine stains (PWSs) have not been reported. The purpose of this study was to evaluate the high-frequency US findings of PWSs.

METHODS

We retrospectively reviewed 98 PWS cases and categorized them into 4 groups based on clinical manifestations and pathologic findings (14 nodular, 28 thickened, 52 flattened, and 4 acquired). We evaluated the US findings with 10- and 22-MHz transducers.

RESULTS

For nodular PWSs, the mean thickened skin ± SD was 0.6 ± 0.5 mm, and the nodule thickness was 5.7 ± 3.3 mm; 63.6% of skin lesions showed vessel density of 2.16 ± 0.93/cm² with venous flow of 4.6 ± 1.1 cm/s, and all nodules showed vessel density of 6.14 ± 1.92/cm² with arterial and venous flow of 26.6 ± 17.9 and 9.9 ± 5.1 cm/s, respectively. The thickened skin of the thickened type was 1.4 ± 2.7 mm; 76.5% of skin lesions showed vessel density of 3.81 ± 1.98/cm² with venous flow 4.6 ± 2.1 cm/s. The thickened skin of 36 flattened lesions was 0.1 ± 0.1 mm; 91.7% of skin lesions showed vessel density of 1.08 ± 0.28/cm² . The thickened skin of 4 acquired lesions was 0.7 ± 0.4 mm; 50% showed vessel density of 1.08 ± 0.28/cm² . The thickened skin and vessel density of nodular and thickened PWSs were thicker and higher than those of the flattened ones. The 22-MHz transducer produced clearer contrast and higher vessel density than the 10-MHz transducer.

CONCLUSIONS

These results showed differences in US findings of PWSs, which may be useful for clinical diagnosis.

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

Proper nomenclature is a major obstacle in understanding and managing vascular anomalies. Often the same term is used for totally different types of lesions or, conversely, the same lesion may be labeled with different terms. Although in recent times there has been a greater understanding of the problems concerning vascular anomalies, episodes of improper use of terminology still remain. The aim of this article, starting from the most recent classification of vascular anomalies, is to provide a clinical and instrumental approach to identifying these lesions and to converge towards a clear and unambiguous terminology that must become univocal among the various operators to avoid diagnostic misunderstandings and therapeutic errors.

Atypically presenting kaposiform hemangioendothelioma of the knee: ultrasound findings

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor of early childhood and infancy. Kasabach-Merritt phenomenon, a common complication of KHE, is characterized by life-threatening thrombocytopenia, hemolytic anemia, and consumption coagulopathy. There may be atypical cases that do not present with Kasabach-Merritt phenomenon and do have atypical imaging findings. Knowledge of atypical imaging features may assist radiologists in identifying KHE. In this report, we present a 4-year-old case of KHE with atypical ultrasound findings.

MRI evaluation of diffuse subcutaneous neurofibroma of the lower limb in a low resource setting

An unusual type of neurofibroma predominantly seen in children and young adults is diffuse neurofibroma. We present a 25-year-old female with recurring soft tissue masses in her right lower limb. MRI showed areas of T₁ iso-intensity and T₂ hyperintensity relative to skeletal muscle within the subcutaneous fat. These masses show marked enhancement post gadolinium administration. Histological examination of the excised mass showed diffuse neurofibroma. The rare nature of this tumour and the limited literature describing the imaging features make the diagnosis relatively difficult for a radiologist.

Novel sluggish speed signs on ultrasound is indicative of hemangiomas

Background Hemangiomas are sometimes difficult to diagnose with current techniques. Sluggish speed signs (SSS) are a phenomenon that: (i) cannot be depicted as Doppler flow on Doppler ultrasound; (ii) can be observed as fluid movements on Doppler ultrasound; and (iii) cannot be depicted as waveforms on pulse Doppler mode. We hypothesized that SSS could be diagnostic indicators for hemangiomas. Purpose To evaluate whether ultrasound findings, in particular those relating to SSS, are a reliable tool for detecting hemangiomas compared to magnetic resonance imaging (MRI) and the gold standard for hemangioma diagnosis: pathological examination by biopsy or after surgical resection. Material and Methods Totally, 105 patients (mean age, 44.9 years) with soft-tissue tumors underwent MRI and ultrasound examination before biopsy or tumor resection. Ultrasound findings were compared with MRI as well as pathological findings, which were used as reference. Results Hemangiomas were identified in 16 (6.25%) of the 105 patients. On MRI, flow voids showed sensitivity and specificity values of 81.3% and 96.6%, respectively. On ultrasound examination, SSS was the only finding to show equally high sensitivity (93.8%) and specificity (96.6%) for diagnosing hemangiomas. There was no significant difference in the diagnostic capabilities between these two parameters ( P = 0.479). Conclusion SSS showed a high sensitivity and specificity for diagnosing hemangiomas and therefore are useful diagnostic tools to supplement MRI.

Clinical and sonographic features of pediatric soft-tissue vascular anomalies part 1: classification, sonographic approach and vascular tumors

Sonography can be used in the management of pediatric soft-tissue vascular anomalies for diagnosing, for assessing lesion extent and for evaluating complications and response to therapy. The sonographic technique includes a combination of gray-scale imaging with color and spectral Doppler techniques. However the interpretation of the sonographic findings requires correlation with the clinical findings, some of which can be easily obtained at the time of scanning. This has to be combined with the use of appropriate nomenclature and the most updated classification in order to categorize these children into the appropriate management pathway. In this article, which is part 1 of a two-part series, the authors review the current classification of vascular anomalies, provide a clinical and a sonographic approach to these lesions, and review the most relevant clinical and sonographic features of vascular tumors including infantile and congenital hemangiomas, tufted angioma, kaposiform hemangioendothelioma, pyogenic granuloma, intramuscular capillary-type hemangioma and angiosarcoma.

Understanding venous malformations of the head and neck: a comprehensive insight

Venous malformations (VMs) are congenital vascular malformations. They are very often misnamed and thus incorrectly managed. The aim of the present paper is to provide the reader with the most updated literature available and to offer a detailed description of each single aspect of this disease. In detail, the paper discusses the epidemiology, the embryological origins and the physiopathology of VMs. Then, the clinical features of sporadic, inherited and syndromic VMs are discussed. The instrumental diagnosis is presented, and the role of US, CT, MRI and phlebography is pointed out. Differential diagnoses with other vascular malformations and tumors are described. The clinical session ends with the staging of VMs relying on MRI and rheological features. All aspects of treatment are described: conservative measures, medical treatment, sclerotherapy, laser and surgery are thoroughly discussed. A section is reserved to bony VMs. Their clinical aspects and the appropriate treatment are presented.

Fat-containing soft-tissue masses in children

The diagnosis of soft-tissue masses in children can be difficult because of the frequently nonspecific clinical and imaging characteristics of these lesions. However key findings on imaging can aid in diagnosis. The identification of macroscopic fat within a soft-tissue mass narrows the differential diagnosis considerably and suggests a high likelihood of a benign etiology in children. Fat can be difficult to detect with sonography because of the variable appearance of fat using this modality. Fat is easier to recognize using MRI, particularly with the aid of fat-suppression techniques. Although a large portion of fat-containing masses in children are adipocytic tumors, a variety of other tumors and mass-like conditions that contain fat should be considered by the radiologist confronted with a fat-containing mass in a child. In this article we review the sonographic and MRI findings in the most relevant fat-containing soft-tissue masses in the pediatric age group, including adipocytic tumors (lipoma, angiolipoma, lipomatosis, lipoblastoma, lipomatosis of nerve, and liposarcoma); fibroblastic/myofibroblastic tumors (fibrous hamartoma of infancy and lipofibromatosis); vascular anomalies (involuting hemangioma, intramuscular capillary hemangioma, phosphate and tensin homologue (PTEN) hamartoma of soft tissue, fibro-adipose vascular anomaly), and other miscellaneous entities, such as fat necrosis and epigastric hernia.

Venous malformations of the head and neck: current concepts in management

Low-flow venous malformations are congenital lesions and they are the third most common vascular anomaly in the head and neck. In this paper, the third in a series of three educational reviews, we discuss current trends in their management, and include a summary of common sclerosant agents used in their control.

Ultrasound Examination of Pediatric Musculoskeletal Diseases and Neonatal Spine

Ultrasound (US) is a simple, non-invasive imaging modality which allows high-resolution imaging of the musculoskeletal (MSK) system. Its increasing popularity in pediatrics is due to the fact that it does not involve radiation, has an ability to visualize non-ossified cartilaginous and vascular structures, allows dynamic imaging and quick contralateral comparison. US is the primary imaging modality in some pediatric MSK conditions like infant hip in developmental dysplasia (DDH), hip joint effusion, epiphyseal trauma and evaluation of the neonatal spine. US is the modality of choice in infants with DDH, both in the initial evaluation and post-treatment follow-up. US has a sensitivity equivalent to MRI in evaluation of the neonatal spine in experienced hands and is a good screening modality in neonates with suspected occult neural tube defects. In other MSK applications, it is often used for the initial diagnosis or in addition to other imaging modalities. In trauma and infections, US can often detect early and subtle soft tissue abnormalities and a quick comparison with the contralateral side aids in diagnoses. Dynamic imaging is crucial in evaluating congenital instabilities and dislocations, soft tissue and ligamentous injuries, epiphyseal injuries and fracture separations. High-resolution imaging along with color Doppler (CD) is useful in the characterization of soft tissue masses. This article reviews the applications of US in pediatric MSK with emphasis on conditions where it is a primary modality. Limitations of US include inability to penetrate bone, hence, limited diagnosis of intraosseous pathology and operator dependency.

Diagnosis of infantile myofibromatosis with pseudo-ulcerated plaque using prenatal ultrasound: A case report

The present case report describes a case of infantile myofibromatosis (IM) with a pseudo-ulcerated plaque on the right side of the back of a fetus, detected in the 38th week of gestation using prenatal ultrasound. The fetus was examined weekly by ultrasound to measure the size of the mass. At birth, the scarlet mass was slightly elevated compared with the skin around it, with a cavity in the center. It appeared similar to an ulcerated plaque, but the surface of the mass was intact and smooth with a stratum lucidum. Thus, the mass was indicated to be a pseudo-ulcerated plaque. Three months later, the mass had grown larger and so was removed by surgery. The pathology of the mass was confirmed as IM. It is suggested that IM should be considered when a soft tissue tumor is presented by prenatal ultrasound.

S.E. Mitchell Vascular Anomalies Flow Chart (SEMVAFC): a visual pathway combining clinical and imaging findings for classification of soft-tissue vascular anomalies

Classification of vascular anomalies (VAs) is challenging due to overlapping clinical symptoms, confusing terminology in the literature and unfamiliarity with this complex entity. It is important to recognize that VAs include two distinct entities, vascular tumours (VTs) and vascular malformations (VaMs). In this article, we describe SE Mitchell Vascular Anomalies Flow Chart (SEMVAFC), which arises from a multidisciplinary approach that incorporates clinical symptoms, physical examination and magnetic resonance imaging (MRI) findings to establish International Society for the Study of Vascular Anomalies (ISSVA)-based classification of the VAs. SEMVAFC provides a clear visual pathway for physicians to accurately diagnose Vas, which is important as treatment, management, and prognosis differ between VTs and VaMs.

Ultrasound evaluation of superficial lumps and bumps of the extremities in children: a 5-year retrospective review

Ultrasonography is commonly requested for evaluation of palpable soft-tissue masses of the extremities in children. Although malignancy is quite rare in these children, it remains a primary diagnostic concern. As a result, knowledge of the common and uncommon soft-tissue lesions as well as sonographic techniques for optimized evaluation are crucial for accurate assessment. This review describe the sonographic imaging appearance of the most commonly encountered superficial soft-tissue lesions at a tertiary academic pediatric hospital. Features of malignancy and findings warranting further evaluation such as lesion size, heterogeneity, vascularity and depth of involvement are also discussed.

Musculoskeletal ultrasonography of the lower extremities in infants and children

Ultrasonography is a powerful diagnostic imaging tool for evaluating lower extremity anatomy and pathology in children. Indications for pediatric musculoskeletal lower extremity sonography include developmental dysplasia of the hip, hip joint sonography for the child with a painful hip, evaluation and characterization of superficial soft-tissue masses, evaluation for deep venous thrombosis, and foreign body localization, characterization and removal. This review highlights these established indications, but primarily focuses on additional US applications for evaluation of the lower extremities, including diagnosis and characterization of arthritis and monitoring of therapy, evaluation of tendon tears and muscle strain injuries, characterization of soft-tissue masses and evaluation of certain congenital abnormalities of the lower extremities. Techniques for optimal utilization of musculoskeletal US in children are also discussed.

Colour Doppler ultrasound imaging findings in paediatric periocular and orbital haemangiomas

PURPOSE

To evaluate the combined grey-scale ultrasonography (US) and colour Doppler imaging (CDI) as the first and primary imaging modalities in diagnosing paediatric orbital haemangiomas.

METHODS

The charts of 20 consecutive children with a periorbital mass echographically diagnosed as a haemangioma between January 2004 and June 2009 in the Tel-Aviv Sourasky Medical Center were reviewed. Data on demographic details, clinical findings, US and CDI characteristics, treatment and outcome were retrieved.

RESULTS

Twelve (60%) haemangiomas were located on the upper eyelid, five in the lower eyelid (25%) and three in the medial cantus (15%). The tumour resolved completely in 10 children (50%) and in 10 children (50%) partial resolution was documented. Seven (35%) patients underwent treatment (intralesional or oral steroids or propranolol). Grey-scale US depicted a solid-tissue mass with low internal echogenicity. Mean haemangioma volume was 1.33 cm(3) . Colour Doppler imaging demonstrated intralesional flow with a mean peak systolic velocity of 15.2 cm per second and a mean resistance index of 0.51. All US and CDI examinations were carried out on alert children and no sedation or general anaesthesia was needed. During mean follow-up time of 23 months, no child required any additional imaging or diagnostic procedures to confirm the diagnosis.

CONCLUSION

Combined US and CDI are suggested as the first imaging modalities in cases with a suspected diagnosis of periocular and orbital capillary haemangioma.

Deep congenital hemangioma: prenatal diagnosis and follow-up

Congenital hemangiomas (CHs) are rare benign vascular tumors that are present at birth after full development in utero. With the increasing importance of prenatal screening and improved imaging techniques, vascular tumors will be detected more frequently during examination. Ultrasonographers and obstetricians should be aware of these vascular tumors, their differential diagnosis and prognosis. Not only caregivers need optimal counseling, but also the professionals involved should have knowledge about these anomalies because of an increased risk of complications during and after the delivery of the child. Here, we present a child with a CH of the leg and discuss prenatal diagnosis, intra-partum management, and postnatal follow-up.

Ultrasound of the pediatric chest

Historically, the evaluation of the pediatric chest has been accomplished via CT and conventional radiography. Our objective is to discuss and illustrate the role of US as a non-ionizing radiation alternative in the evaluation of the pediatric chest. US is a valuable tool in the evaluation of the pediatric chest. It can be used as a first-line modality in the evaluation of superficial lumps and bumps of the chest wall, diaphragmatic motion, the thymus and pleural effusions, and it can play a valuable secondary role in evaluation of mediastinal masses and pulmonary parenchymal disease.

Neonatal soft tissue sarcomas

Soft tissue tumors in very young children pose diagnostic and therapeutic challenges. Vascular tumors are the most prevalent soft tissue neoplasms in the neonatal period. They are generally benign tumors, but may exhibit aggressive behaviour and cause life-threatening complications. Fibroblastic tumors of intermediate prognosis, more prevalent in very young children (especially infantile fibrosarcoma), are locally aggressive. Since metastases are unusual in this group of tumors, complete surgical resection is generally curative. However, these tumors often present a therapeutic challenge because of the location which makes complete surgical resection difficult. Among the malignant soft tissue tumors, rhabdomyosarcoma is most frequent. It is an aggressive high-grade tumor, with local invasiveness and a propensity to metastasize. These tumors respond to chemotherapy and radiotherapy. Neonates with rhabdomyosarcoma seem to have a worse prognosis than in older age groups. This may be a result of inappropriate dosing of chemotherapeutic agents and decreased use of radiation therapy among other factors.

Infantile hemangiomas: A review

Infantile hemangiomas (IH) are the most common eyelid and orbital tumors of childhood. Although they are considered benign lesions that have a generally self-limited course, in the periocular region, they have the potential to cause amblyopia, strabismus, and severe disfigurement. The decision for treatment can be a source of anxiety for patients, parents, and physicians alike. There are numerous treatment modalities, including emerging therapies that may make treatment safer and more effective than ever before. This review discusses our current understanding of this disease, its management, and future therapies.

Recent progress in studies of infantile hemangioma

A hallmark of infantile hemangioma, the most common tumor of infancy, is its dramatic growth after birth, by diffuse proliferation of immature endothelial cells, followed by spontaneous regression. The growth and involution of infantile hemangioma is quite different from other vascular anomalies, which do not regress and can occur at any time during life. Some hemangioma lesions can be extremely disfiguring and destructive to normal tissue and may even be life-threatening. Unfortunately, existing therapeutic approaches have limited success and significant adverse effects of some treatment modalities limit their use. Better understanding of the pathogenesis of hemangioma will enable the development of better therapeutic strategies. Here, we review recent studies and new hypotheses on the pathogenesis of the tumor. Detailed mechanisms of activated vascular endothelial growth factor signaling in tumor cells, identification of their origin and characterization of multipotent stem cells that can give rise to infantile hemangioma are shedding new light on this intriguing vascular tumor.

Vascular anomalies: what a radiologist needs to know

Most haemangiomas and vascular malformations are identified according to clinical criteria. A good knowledge of the classification and clinical characteristics of the vascular anomalies is necessary when managing these patients. However, some cases are challenging either because of an atypical presentation (e.g., soft-tissue mass with normal overlying skin) or because of classification difficulties. Doppler US and MRI are the two main imaging modalities that allow classification of the vascular anomalies and are useful in those clinically uncertain cases to establish the correct diagnosis. This aids the choice of the most appropriate treatment and to inform the parents of the prognosis. High-resolution grey-scale and Doppler US allow excellent visualization of most superficial masses. Doppler US is the easiest way to assess the haemodynamics of a vascular lesion and to clarify a doubtful diagnosis between a haemangioma and vascular malformation. MRI is the best technique for evaluating the extent of the lesions and their relationship to adjacent structures. While newly developed drugs from angiogenesis research labs are awaited, radiologists have an important role in the treatment of haemangiomas and vascular malformations. Intervention remains crucial in cases of alarming haemangiomas and venous malformations (VM), lymphatic malformations (LM) and arteriovenous malformations (AVM). A multidisciplinary team, including paediatricians, haematologists, surgeons and radiologists, must manage the problem cases both in terms of diagnostic work-up and therapeutic options. This paper will briefly discuss the imaging findings and treatment of vascular anomalies.

Rapidly involuting congenital hemangioma: a case of complete prenatal involution

We report a case of rapidly involuting congenital hemangioma of the flank, which was diagnosed in the 2(nd) trimester of gestation and showed complete involution before term. In our case sonography revealed a highly vascular soft tissue mass with smooth contours, which was isointense with the placenta on T2-weighted MR images. The fetus was born with scar tissue at the site of the lesion. To our knowledge this is the 1(st) reported case of rapidly involuting congenital hemangioma showing complete involution before term.

[Infantile hemangiomas: differential diagnosis and associated anomalies]

Infantile hemangiomas are frequent benign vascular tumors that are often easily recognized. However, the diagnosis between infantile hemangiomas and other vascular tumors, whether benign or malignant, may be difficult. This chapter describes the different clinical presentations of hemangiomas and details the investigations that are needed to confirm the nature of the lesion and to diagnose the potentially associated anomalies. Knowledge on differential diagnosis enables clinicians to detect hemangiomas that can lead to complications and that necessitate a multidisciplinary approach.

Tumeurs et malformations vasculaires, classification anatomopathologique et imagerie

The understanding of vascular anomalies (vascular tumours and vascular malformations) was obscured, for a long time, by confusion and uncertainties in nosology and terminology. The International Society for the Study of Vascular Anomalies (ISSVA) recently adopted a classification scheme, clearly separating vascular tumours (hemangiomas of different types) which result from active cell proliferation, from vascular malformations, which are inborn defects in vascular morphogenesis. These two types of lesions have different clinical behaviour and require different diagnostic and therapeutic strategies. The most frequent vascular tumour is infantile hemangioma. Its clinical aspects and evolution are well-known. New data have been recently obtained concerning the phenotype of tumour cells and its histogenesis. Of the numerous new vascular tumours, which have been recently described, only the congenital hemangiomas, the vascular tumours associated with the Maffucci syndrome and the tumours that may be complicated by a profound thrombocytopenia (Kasabach and Merritt phenomenon) will be considered. Vascular malformations can be classified according to the vessel(s) types they are composed of. A classification table is presented, separating the malformations of vascular trunks from tissular malformations which are more intimately embedded in the surrounding tissues. The different syndromes associated with vascular anomalies take also place in this table. The clinical, imaging and histological aspects of the most frequent malformations (capillary, venous, lymphatic and arteriovenous) are presented. This classification intend to clarify the nosology and terminology of the complex field of vascular tumours and malformation and to offer a common language to the different physicians and specialists contributing, preferably with a interdisciplinary approach, to the diagnosis and treatment of these difficult lesions.

Diagnostic prénatal et prise en charge d’un cas d’hémangiome congénital du cuir chevelu

Rapidly involuting congenital hemangioma (RICH) is a rare vascular lesion, identified in 1996, of elective localization in the dermal-hypodermic tissue. Its name comes from its particular natural course: it is fully developed at birth and then completely involutes, usually in the first year. We present a case of a RICH of the scalp discovered with a screening ultrasonography in the 31st week of gestation. We list the differential diagnoses. After birth, positive diagnosis lies preferably on pathology examination of a biopsy specimen in order to eliminate the hypothesis of a less favorable vascular lesion, teratoma or malignant tumor.

Subcutaneous angioleiomyomas: gray-scale and color Doppler sonographic appearances

PURPOSE

To describe the gray-scale Doppler and sonographic features of a series of subcutaneous angioleiomyomas.

METHODS

The sonographic appearances of 10 pathologically proven angioleiomyomas were retrospectively reviewed; 4 in women and 6 in men, with an age range from 33 to 77 years. We evaluated size, shape, echo pattern, margins, location, relationships with adjacent structures, and vascularity. Examinations were performed using a multifrequency linear array transducer (9-11 MHz) connected to a Logiq 500 scanner (GE, Milwaukee, Wl).

RESULTS

All tumors were subcutaneous and located in the extremities (7 in the lower extremities, 3 in the upper extremities). The sizes ranged from 0.6 to 6.4 cm, with an average size of 2 cm. All of the lesions were hypoechoic with well-defined margins, and 9 were oval. Intratumoral calcifications were observed in two patients. Vascularity was easily detected in all of them, and 4 tumors had a clear vascular pedicle. The spectral Doppler analysis performed in 5 cases, revealing a low-resistance arterial waveform in 4 patients.

CONCLUSIONS

Although angioleiomyomas are uncommon soft tissue tumors, the presence of a well-defined, hypoechoic, vascular subcutaneous tumor in the extremities should raise the possibility of such a diagnosis.

Imaging and diagnostic strategy of soft tissue tumors in children

The diagnosis of a soft tissue mass in children is a common clinical situation. Most of the lesions are benign and can be treated conservatively or by non-mutilating surgery. Nevertheless, the possibility of a malignant soft tissue tumor must be systematically considered. The most frequent benign soft tissue lesions in children are vascular lesions, fibrous and fibrohistiocytic tumors and pseudotumors, whereas rhabdomyosarcomas account for 50% of all soft tissue sarcomas. A child presenting an atypical soft tissue mass should be managed by a multidisciplinary centre, and primary resection must be proscribed until a definite diagnosis has been established. The role of imaging is essential either to confirm the benign nature of the mass or to give arguments to perform a diagnostic biopsy. Clinical examination, conventional radiography and ultrasound with Doppler represent the first-line examinations and are sometimes sufficient to assess a diagnosis. In all other situations, MRI is mandatory to establish the probable nature of the lesion and to assess local extension.

Imaging characteristics of two subtypes of congenital hemangiomas: rapidly involuting congenital hemangiomas and non-involuting congenital hemangiomas

BACKGROUND

Common infantile hemangiomas (COMMON) occur in approximately 10% of infants by the age of 1 year, with a female predominance. Some hemangiomas can be fully developed at birth and are thus called congenital hemangiomas (CH). Within this population, two courses have been identified: rapidly involuting CH (RICH) and non-involuting CH (NICH). Little has been reported on the clinical prognosis and imaging features of these entities.

OBJECTIVE

To describe the imaging characteristics of two subtypes of CH, i.e. RICH and NICH, and to compare them with COMMON.

MATERIALS AND METHODS

We retrospectively gathered data on 26 children presenting with CH, i.e. lesions fully developed at birth. These lesions were divided into two groups according to the clinical course: suspected RICH (n=8) and suspected NICH (n=18). We used US, CT or MRI and angiography to identify the gross anatomy and structure and the vascularization. Imaging findings were compared with the clinical course and pathology results, when available. The imaging findings in these patients were compared retrospectively with those in 26 patients with COMMON randomly chosen from the database of our multidisciplinary clinic.

RESULTS

When compared with COMMON imaging characteristics, NICH and RICH had distinctive features on US such as being heterogeneous (72% of NICH and 62.5% of RICH vs 42.3% of COMMON), visible vessels (72% of NICH and 62.5% of RICH vs 15.4% of COMMON), calcifications (17% of NICH and 37.5% of RICH vs no case of COMMON). On CT and/or MRI, we compared imaging features such as well-defined limits (67% of NICH and 60% of RICH vs 100% of COMMON), and fat stranding (29.4% of NICH and RICH vs 7.7% of COMMON).

CONCLUSION

Distinctive imaging characteristics are observed in cases of CH with US findings of visible vessels and calcifications statistically significant.