Vascular anomalies: hemangiomas and beyond--part 1, Fast-flow lesions

Successful treatment by coil embolization for pediatric brachial arteriovenous fistula: A case report

Arteriovenous fistulae of the upper limbs are rare in the pediatric population. They can be caused by trauma, needle puncture, or other iatrogenic injuries. A 5-year-old boy presented with progressive swelling of the right hand, which was initially misinterpreted as an arteriovenous malformation based on his noninvasive diagnostic work-up. He was ultimately diagnosed with right brachiocephalic arteriovenous fistula by catheter angiography, and the fistula was then successfully treated with coil embolization. This article describes the relevant imaging findings and potential implications for treatment.

Surgical Navigation and CAD-CAM-Designed PEEK Prosthesis for the Surgical Treatment of Facial Intraosseous Vascular Anomalies

Background: Intraosseous vascular anomalies in the facial skeleton present significant diagnostic and therapeutic challenges due to complex anatomy. These anomalies represent about 0.5-1% of bony neoplastic and tumor-like lesions, usually presenting as a firm, painless mass. Most described intraosseous vascular malformations are venous malformations (VMs) and, more rarely, arteriovenous malformations. Objectives: The objectives of this work are to show our experience, protocol and the applications of computer planning, virtual surgery, CAD-CAM design, surgical navigation, and computer-assisted navigated piezoelectric surgery in the treatment of facial intraosseous vascular anomalies and to evaluate the advantages and disadvantages. Methods: Three females and one male with periorbital intraosseous vascular anomalies were treated using en-block resection and immediate reconstruction with a custom-made PEEK prosthesis. One lesion was in the supraorbital rim and orbital roof, one in the frontal bone and orbital roof, and two in the zygomatic region. We accomplished the resection and reconstruction of the lesion using virtual planning, CAD-CAM design, surgical navigation and piezoelectric device navigation. Results: There were no complications related to the surgery assisted with navigation. With an accuracy of less than 1 mm, the procedure may be carried out in accordance with the surgical plan. The surgeon's degree of uncertainty during deep osteotomies and in locations with low visibility was decreased by the use of the navigated piezoelectric device. Conclusions: Resection and reconstruction of facial intraosseous vascular anomalies benefit from this new surgical strategy using CAD-CAM technologies, computer-assisted navigated piezoelectric surgery, and surgical navigation.

Pediatric orbital lesions: neoplastic extraocular soft-tissue lesions

Pediatric neoplastic extraocular soft-tissue lesions in the orbit are uncommon. Early multimodality imaging work-up and recognition of the key imaging features of these lesions allow narrowing of the differential diagnoses in order to direct timely management. In this paper, the authors present a multimodality approach to the imaging work-up of these lesions and highlight the use of ocular ultrasound as a first imaging modality where appropriate. We will discuss vascular neoplasms (congenital hemangioma, infantile hemangioma), optic nerve lesions (meningioma, optic nerve glioma), and other neoplastic lesions (plexiform neurofibroma, teratoma, chloroma, rhabdomyosarcoma, infantile fibrosarcoma, schwannoma).

Retroperitoneal venous malformation mimics paraganglioma on triple imaging modalities

Here, we report a case of a woman in her 50s who was referred for an incidentally discovered lesion anterior to the origin of inferior vena cava suspicious for a paraganglioma following a CT scan for vaginal bleeding. A follow-up 68Ga-DOTATATE PET-CT and MRI of the abdomen reinforced the radiological impression of an extra-adrenal paraganglioma (EAP). The EAP was deemed non-functional given normal urine biogenic amine, supine plasma fractionated metanephrines and chromogranin A levels. The mass was resected laparoscopically without perioperative blockade. Histological examination revealed a venous malformation. Extrahepatic abdominal venous malformations are rare and can be indistinguishable from an EAP on imaging preoperatively. Although benign, the lesion nevertheless warrants excision as it is associated with a risk of haemorrhage.

To Draw a Detailed Map for Maxillofacial Fast-Flow Vascular Diseases With the Combination of Color Doppler Ultrasound and Three-Dimensional Computed Tomography Angiography

Vascular diseases, such as vascular malformations and hemangiomas, are often classified into "fast-flow" and "slow-flow" based on their internal blood velocity. Fast-flow vascular diseases of maxillofacial regions are a kind of complicated and dangerous pathological changes originating from or containing arteries, their treatment is often complex and different from disease to disease, and large amounts of intraoperative blood loss and poor operation field may cause side injury or other problems without a detailed map of the lesion. The authors use the combination of color Doppler ultrasound and three-dimensional computed tomography angiography to diagnose and classify 36 cases of maxillofacial fast-flow vascular diseases, from January 2018 to December 2022 presented in the authors' department. Three-dimensional computed tomography angiography can display the location, type, and blood supply of lesions, whereas color Doppler ultrasound has unique advantages in identifying some special lesions (such as the colorful images of orificium fistulaes and the "Yin-yang sign" of pseudoaneurysms), then projecting and marking them on the body surface, which greatly facilitate the surgical procedure. This cost-effective and noninvasive combination shows significant clinical application value.

Clinical and imaging features of Kaposiform hemangioendothelioma in infants

Objective

Kaposiform hemangioendothelioma (KHE) is a locally aggressive tumor of vascular origin. This study investigated the clinical and imaging features of KHE to provide a reference for its early diagnosis.

Methods

The clinical and imaging findings of 27 clinically confirmed KHE cases (including 21 with focal lesions and 6 with diffuse lesions) between January 2016 and December 2021 were retrospectively analyzed.

Results

The mean age of the 27 patients was 105 ± 80.27 days. Twenty-two (81.5%) of these patients had Kasabach-Merritt phenomenon. Most KHEs were located in the trunk and/or extremities (22/27). Ultrasonography showed heterogeneous echogenicity and/or striated hypoechoic bands with abundant or patchy blood flow within the tumor. On plain computed tomography (CT), they appeared as heterogeneous lesions isodense with the muscles, with a CT value of 29.58 ± 11.53 HU. In the arterial phase, the KHEs showed striated or lamellar heterogeneous enhancement, with a CT value of 153.91 ± 52.11 HU after enhancement. All KHEs showed uneven and high signal intensity on T2-weighted imaging, mixed high and low signal intensity on fat-saturated images, and no significant diffusion restriction on diffusion-weighted imaging.

Conclusion

KHEs can occur in various locations and present as highly infiltrative and heterogeneous masses that can invade the skin, adjacent muscles, and bones. A vascularized mass with purpuric skin changes, with uneven and high T2WI signal is highly suggestive of the diagnosis of KHE.

Prenatal diagnosis of vascular anomalies

Vascular anomalies are rare disorders that encompass a group of lesions characterized by abnormal development of the lymphovascular system. Majority of these anomalies are present at birth and could potentially be detected during the prenatal period on imaging. This allows for early intervention and prompt management to improve outcomes. However, they can be difficult to diagnose, given the rarity and overlapping findings. In this review article, we provide a comprehensive overview of congenital vascular anomalies with a liberal use of images of recent cases at our center emphasizing prenatal imaging findings and the natural history of these conditions.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 2: vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5^th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous organ soft tissues, as well as the peripheral and autonomic nervous system.

Sirolimus used for treatment of retroperitoneal arteriovenous malformation in a premature neonate

We describe a case of a premature infant with antenatally detected retroperitoneal arteriovenous malformation (AVM) with extensive intraspinal extension. Treatment of the malformation with embolectomy and sclerotherapy was not feasible in view of intraspinal extensions and small size of vessels of the lesion. During a trial of propranolol over 20 days, the lesion progressed in size, roughly doubling in volume and was accompanied with deranged coagulation parameters. Treatment was therefore switched to oral prednisolone and sirolimus. The steroid was stopped after 6 weeks and sirolimus was continued with serum drug level monitoring and serial imaging of the malformation. After 4 months of sirolimus, the AVM remained at the same size as at the start of treatment, thus we propose that the drug may have arrested the growth of the lesion. This case highlights the use of sirolimus in management of AVMs in infants.

Pediatric chest wall masses: spectrum of benign findings on ultrasound

A palpable finding along the chest wall is a frequent indication for pediatric US. Accurate identification of benign lesions can reassure families and appropriately triage children who need follow-up, cross-sectional imaging, or biopsy. In this pictorial essay, we review chest wall anatomy, illustrate US techniques and discuss key US imaging features of common benign lesions and normal variants.

Antiproliferative therapy with sirolimus and propranolol for congenital vascular anomalies in newborns (Case reports)

We present a series of four newborns diagnosed with complicated congenital vascular anomalies, with different localization: Congenital lymphatic malformation (CLM) on the left hemithorax extending on the left upper limb; congenital hepatic hemangioma (CHH) with important complications in the first 7 weeks of life; Kaposiform hemangioendothelioma (KHE) of the left lower limb complicated with Kasabach Merritt phenomenon (KMM) and most probable diffuse capillary malformation with overgrowth (DCMO). All patients were treated with combined antiproliferative therapy with sirolimus and propranolol. The initial dose of sirolimus was 0.45-0.5 mg/m² with doses adjusted according to plasmatic levels. Therapeutic intervals of sirolimus were considered at plasmatic levels of 7-12 ng/ml. Our aim was to use the lowest therapeutic dose in order to avoid possible side effects. Propranolol was initiated in doses of 0.5-1.0 mg/kg/day and was increased up to 3.0 mg/kg/day depending on tolerability. Following two months, every patient showed a marked reduction in the size of the mass, improvement in overall appearance or even calcification in the liver vascular tumor. No patient showed life threatening side effects to the treatment. Hypertriglyceridemia was the only side effect noted in all patients. This is in accordance with several international studies, which try to demonstrate the importance of sirolimus in neonatal vascular malformations in monotherapy or combined with different drugs.

Sonography of pediatric gastrointestinal venous malformations

Gastrointestinal (GI) venous malformations are extremely rare. Such malformations present in the pediatric age group and can occur anywhere in the digestive tract (esophagus, stomach, small or large intestine, anus, and mesentery). We present the sonographic findings of three cases of pediatric GI venous malformation. Sonography is an important diagnostic method in pediatric GI venous malformations.

3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo

PURPOSE

 To assess morphological and hemodynamic characteristics of peripheral vascular malformations on 3 T magnetic resonance imaging (MRI) including qualitative comparison of two fat-saturated sequences: short tau inversion recovery (STIR) and three-dimensional high-resolution volume interpolated gradient recalled echo (GRE).

MATERIALS AND METHODS

 During 9 months, 100 patients with suspected or known vascular malformations were prospectively assessed on a 3 T scanner using T2-weighted STIR and turbo spin echo (TSE), T1-weighted TSE, time-resolved contrast-enhanced magnetic resonance angiography (MRA) with interleaved stochastic trajectories (TWIST) and T1-weighted volume interpolated breath-hold examination (VIBE) after contrast enhancement. The analysis included signal behavior and morphologic and hemodynamic characteristics. Additionally, the image quality of the fat-saturated sequences was evaluated by 2 radiologists.

RESULTS

 86 patients (14 dropouts; 57 female, 29 male; mean age 26.8 years, age range 1-56) were analyzed. 22 had high-flow and 64 low-flow malformations, including 14 with a lymphatic component. In 21 of 22 patients with high-flow malformations, typical characteristics (flow voids, hyperdynamic arteriovenous fistula, dilated main/feeder-arteries and draining veins) were documented. Patients with low-flow malformations had phleboliths in 35 cases, fluid-fluid levels in 47 and dilated draining veins in 23. Lymphatic malformations showed peripheral contrast enhancement of cyst walls in the volume interpolated GRE. The comparison of fat-saturated sequences showed significantly better results of the volume interpolated GRE in all categories except the presence of artifacts which were significantly reduced in the STIR (p < 0.05).

CONCLUSION

 3 T MRI with MRA provides detailed morphological and hemodynamic information of different types of peripheral vascular malformations. Contrast-enhanced high-resolution volume interpolated GRE proved superior to STIR in differentiating morphologic features and to be diagnostic in the differentiation of lymphatic parts and joint involvement.

KEY POINTS

  · 3 T MRI with MRA offers detailed information about vascular malformations.. · Fat-saturated MRI provides especially information about morphological characteristics, extent and tissue involvement.. · Volume interpolated GRE proved superior in almost all categories compared to STIR.. · Volume interpolated GRE showed more artifacts.. · Volume interpolated GRE additionally allows differentiation of lymphatic parts and evaluation of joint involvement..

CITATION FORMAT

· Höhn F, Hammer S, Fellner C et al. 3T MRI of Peripheral Vascular Malformations: Characteristics and Comparison of Two Fat-Saturated sequences: Short Tau Inversion Recovery Versus Three-Dimensional High-Resolution Volume Interpolated Gradient Recalled Echo. Fortschr Röntgenstr 2021; 193: 446 - 458.

Imaging of Vascular Malformations

Recent advances in imaging have allowed a better understanding of imaging features and classification of vascular anomalies. This article focuses on imaging of vascular malformations; describes the updated classification system and clinical and imaging characteristics of the different subtypes; and discusses the associated syndromes, differential diagnosis, and available treatment options, including the role of imaging in management.

Spectrum of Imaging Manifestations of Vascular Malformations and Tumors Beyond Childhood: What General Radiologists Need to Know

Vascular anomalies encompass a collection of diagnoses that differ greatly in terms of clinical presentation, natural history, imaging findings, and management. The purpose of this article is to review diagnostic imaging findings of vascular malformations and vascular tumors, excluding the central nervous system, that occur beyond childhood. A widely accepted classification system created by the International Society for the Study of Vascular Anomalies provides a framework for this review, focusing on the entities most likely to be encountered by general radiologists, although several rare but clinically important entities are also reviewed.

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.

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.

Beyond endothelial cells: Vascular endothelial growth factors in heart, vascular anomalies and placenta

Vascular endothelial growth factors regulate vascular and lymphatic growth. Dysregulation of VEGF signaling is connected to many pathological states, including hemangiomas, arteriovenous malformations and placental abnormalities. In heart, VEGF gene transfer induces myocardial angiogenesis. Besides vascular and lymphatic endothelial cells, VEGFs affect multiple other cell types. Understanding VEGF biology and its paracrine signaling properties will offer new targets for novel treatments of several diseases.

Soft-tissue vascular malformations and tumors. Part 1: classification, role of imaging and high-flow lesions

Vascular malformations and tumors, also known as "vascular anomalies", comprise an extensive variety of lesions involving all parts of the body. Knowledge of their classification and imaging characteristics is paramount. Whereas hemangiomas are benign vascular tumors, characterized by cellular proliferation and hyperplasia; vascular malformations are not real tumors and characteristically exhibit normal endothelial turnover. Vascular malformations are classified according to the predominant vascular channel as arterial, capillary, venous, lymphatic, or mixed. Ultrasound and MRI are the main imaging modalities used in the diagnosis and classification of the vascular anomalies. In this series of two articles we review the classification of vascular anomalies, describe the role of imaging, summarize their distinctive histopathogenic, clinical and imaging features, and discuss the treatment options. On the first article we discuss the high-flow lesions, whereas the slow-flow lesions will be reviewed on the second. Complex syndromes with associated vascular tumors and malformations will be also presented.

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.

Assessment of the Pediatric Foot Mass

Masses in the pediatric foot are relatively uncommon and can present a diagnostic challenge. The literature lacks a comprehensive overview of these types of lesions. Most are benign soft-tissue lesions that can be diagnosed on the basis of history and physical examination. However, some rare malignant neoplasms can mimic benign masses. It is imperative to recognize these lesions because the consequences of a delayed or missed diagnosis can be substantial. A thorough history and physical examination of all pediatric patients with foot lesions are crucial to ensure that any lesion not readily identified as benign is appropriately managed.

Sonography of Abdominal Wall Masses and Masslike Lesions: Correlation With Computed Tomography and Magnetic Resonance Imaging

Sonography is usually regarded as a first-line imaging modality for masses and masslike lesions in the abdominal wall. A dynamic study focusing on a painful area or palpable mass and the possibility of ultrasound-guided aspiration or biopsy are the major advantages of sonography. On the other hand, cross-sectional imaging clearly shows anatomy of the abdominal wall; thereby, it is valuable for diagnosing and evaluating the extent of diseases. Cross-sectional imaging can help differentiate neoplastic lesions from non-neoplastic lesions. This pictorial essay focuses on sonographic findings of abdominal wall lesions compared with computed tomographic and magnetic resonance imaging findings.

Imaging evaluation of fetal vascular anomalies

Vascular anomalies can be detected in utero and should be considered in the setting of solid, mixed or cystic lesions in the fetus. Evaluation of the gray-scale and color Doppler US and MRI characteristics can guide diagnosis. We present a case-based pictorial essay to illustrate the prenatal imaging characteristics in 11 pregnancies with vascular malformations (5 lymphatic malformations, 2 Klippel-Trenaunay syndrome, 1 venous-lymphatic malformation, 1 Parkes-Weber syndrome) and vascular tumors (1 congenital hemangioma, 1 kaposiform hemangioendothelioma). Concordance between prenatal and postnatal diagnoses is analyzed, with further discussion regarding potential pitfalls in identification.

High-pitch spiral CT with 3D reformation: an alternative choice for imaging vascular anomalies with affluent blood flow in the head and neck of infants and children

OBJECTIVE

To evaluate the feasibility of high-pitch spiral CT in imaging vascular anomalies (VAs) with affluent blood flow in the head and neck of infants and children.

METHODS

For patients with suspected VAs and affluent blood flow pre-detected by ultrasound, CT was performed with high-pitch mode, individualized low-dose scan protocol and three-dimensional (3D) reformation. A five-point scale was used for image quality evaluation. Diagnostic accuracy was calculated with clinical diagnosis with/without pathological results as the reference standard. Radiation exposure and single-phase scan time were recorded. Treatment strategies were formulated based on CT images and results and were monitored through follow-up results.

RESULTS

20 lesions were identified in 15 patients (median age of 11 months). The mean score of image quality was 4.13 ± 0.74. 7 patients (7/15, 46.67%) were diagnosed with haemangiomas, 6 patients (6/15, 40%) were diagnosed with venous malformations and 2 patients (2/15, 13.33%) were diagnosed with arteriovenous malformations. The average effective radiation doses of a single phase and of the total procedure were 0.27 ± 0.08 and 0.86 ± 0.21 mSv. The average scanning time of a single phase was 0.46 ± 0.09 s. After treatment, 13 patients (13/15, 86.67%) achieved excellent results, and 2 patients (2/15, 13.33%) showed good results in follow-up visits.

CONCLUSION

High-pitch spiral CT with an individualized low-dose scan protocol and 3D reformation is an effective modality for imaging VAs with affluent blood flow in the head and neck of infants and children when vascular details are needed and ultrasound and MRI could not provide the complete information.

ADVANCES IN KNOWLEDGE

This study proposes an alternative modality for imaging VAs with affluent blood flow.

Benign soft-tissue lesions of the fingers: radiopathological correlation and clinical considerations

Soft-tissue lesions of the fingers are commonly found in daily clinical practice. A wide range of tumors and pseudotumors have been described in this location, and the majority of them are benign. Ganglion cysts are the most common entity, and the localized type of tenosynovial giant cell tumors are the most frequent solid condition. Both may be easily recognized owing to their typical clinical and radiological characteristics. However, categorization of the spectrum of soft-tissue lesions of the fingers remains limited, despite imaging development, and many patients undergo surgery before radiological or histological diagnosis. Clinical history, radiographic features, and ultrasound and magnetic resonance patterns may help in obtaining the correct diagnosis or reducing the list of differential diagnoses. Radiologists should be familiar with imaging findings so that they can determine the size, extension, and affected neighboring anatomical structures, and provide information that allows adequate presurgical counseling.

Clinical spectrum of capillary malformation-arteriovenous malformation syndrome presenting to a pediatric dermatology practice: a retrospective study

Capillary malformation-arteriovenous malformation syndrome (CM-AVM) is an autosomal dominant disorder caused by RASA1 mutations. The prevalence and phenotypic spectrum are unknown. Evaluation of patients with multiple CMs is challenging because associated AVMs can be life threatening. The objective of this study was to describe the clinical characteristics of children presenting with features of CM-AVM to an academic pediatric dermatology practice. After institutional review board approval was received, a retrospective chart review was performed of patients presenting between 2009 and 2012 with features of CM-AVM. We report nine cases. Presenting symptoms ranged from extensive vascular stains and cardiac failure to CMs noted incidentally during routine skin examination. All demonstrated multiple CMs, two had Parkes Weber syndrome, and two had multiple infantile hemangiomas. Seven patients had family histories of multiple CMs; three had family histories of large, atypical CMs. Six had personal or family histories of AVMs. Genetic evaluation was recommended for all and was pursued by six families; four RASA1 mutations were identified, including one de novo. Consultations with neurology, cardiology, and orthopedics were recommended. Most patients (89%) have not required treatment to date. CM-AVM is an underrecognized condition with a wide clinical spectrum that often presents in childhood. Further evaluation may be indicated in patients with multiple CMs. This study is limited by its small and retrospective nature.

Hypervascular mediastinal masses: action points for radiologists

Hypervascular mediastinal masses are a distinct group of rare diseases that include a subset of benign and malignant entities. Characteristic features and known association with syndromes and genetic mutations assist in achieving a diagnosis. Imaging allows an understanding of the vascularity of the lesion and should alert the radiologist and clinician to potential hemorrhagic complications and avoid percutaneous CT guided biopsies. In such cases, pre-procedure embolization and surgical biopsy maybe considered for better control of post procedure hemorrhage. The purpose of this article is to describe and illustrate the clinical features and radiologic spectrum of hypervascular mediastinal masses, and discuss the associated clinical and genetic syndromes. We will present an imaging algorithm to determine further evaluation and subsequently guide treatment.

Imaging of lumps and bumps in pediatric patients: an algorithm for appropriate imaging and pictorial review

Superficial lumps and bumps are a common presenting complaint in the pediatric patient population. Although encountered frequently, the path to a definitive diagnosis is not always a straightforward one. Imaging offers a valuable tool to aid in this diagnostic challenge. Radiologists must be familiar with pediatric lumps and bumps, their imaging characteristics, and the best way to further evaluate challenging clinical presentations. This will not only allow the radiologist to serve as a valuable asset to the treating physician in choosing the most appropriate imaging modality but also help in accurate diagnosis, all while ensuring the "image gently" principle. An algorithm for imaging in the pediatric patient with lumps and bumps has been presented in this article and a few example entities along with their imaging findings have also been reviewed.

FDG-avid venous malformation could mimic malignancy on 18F-FDG PET/CT

A 49-year-old female patient with melanoma underwent FDG PET/CT for surveillance. PET/CT demonstrated multiple mildly FDG-avid soft tissue attenuation lesions in the pelvis of unknown etiology. MRI was performed for further evaluation. MRI demonstrated multiple dilated vascular structures measuring up to 2.5 cm consistent with venous malformation. Follow-up PET/CT 1 and 2 years later demonstrated stable FDG-avid soft-tissue densities in the pelvis representing venous malformation. No recurrence or distant metastases were identified. This case demonstrates how a benign FDG-avid vascular malformation on PET/CT could have been misinterpreted as malignancy. Biopsy of a vascular malformation could have had dire consequences.

Ten frequently asked questions about MRI evaluation of soft-tissue vascular anomalies

OBJECTIVE

The objective of this article was to address 10 frequently asked questions that radiologists face when planning, performing, and interpreting an MRI study in a patient with a soft-tissue vascular anomaly.

CONCLUSION

MRI permits a comprehensive assessment of vascular anomalies. It is important for radiologists to be familiar with the classification and correct nomenclature of vascular anomalies as well as the MRI protocol and distinct imaging findings of the different vascular malformations and tumors.