Cryoablation in fibro-adipose vascular anomaly (FAVA): a minimally invasive treatment option

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.

Progress about the fibro-adipose vascular anomaly: A review

Fibro-adipose vascular anomaly (FAVA) is a rare and complex vascular malformation associated with persistent pain, limb contracture, and even restriction of activity. However, the pathophysiology of FAVA remains unclear. Although FAVA is a benign vascular malformation, it is highly misdiagnosed and often thus undergoing repeated surgical resection and interventional sclerotherapy, resulting in worsening of symptoms and irreversible dysfunction. Therefore, aggressive diagnosis and treatment are essential. There are several different treatment options for FAVA, including surgical resection, sclerotherapy, cryoablation, drug therapy, and physical therapy. This article reviews the clinical manifestations, pathological features, pathogenesis, and treatment methods of FAVA.

Fibro-adipose vascular anomaly (FAVA) - diagnosis, staging and management

BACKGROUND

The diagnosis and treatment of fibro-adipose vascular anomaly (FAVA) of the limb remains challenging since this entity is rare and complex. This paper is aimed to describe the clinical and imaging features, staging and management of this underrecognized disease of the limb.

MATERIAL AND METHOD

Patients diagnosed with FAVA and managed between September 2019 and May 2022 in department of pediatric surgery & vascular anomalies of Xi'an international medical center hospital were retrospectively reviewed. Data extracted include age at presentation, previous diagnosis, affected muscles, symptoms, previous treatment, our management, and follow-up.

RESULTS

Thirty-two patients with FAVA were diagnosed and managed in our center. There was a female sex predominance, with 23 female (72%) and 9 male (28%) in the cohort. Only one lesion was noticed during infancy; the remaining presented at age 1 to 20 years (median, 7 years). The most commonly involved muscles were gastrocnemius (14/32, 44%) and soleus (13/32, 40%). Swelling (mass), pain and contractures were the most common presentations. MRI featured a heterogeneous and ill-defined intramuscular high signal intensity. Diseases were staged according to clinical features: stage I (pain stage, n = 4), stage II (contracture stage, n = 20) and stage III (deformity stage, n = 8). Patients with stage I disease underwent radical resection and obtained a cure. Patients with stage II disease received radical resection and possible Achilles lengthening, having an outcome of cure. Personalized treatment was required in patients with stage III disease, including radical/partial/staged resection, Achilles lengthening/tenotomy, joint capsulotomy, neurolysis/neurectomy, tendon transfer, stretching exercises, and oral sirolimus/alpelisib. Significant improvement of symptoms was achieved in most.

CONCLUSION

The most distinct features of FAVA include enlarging mass, severe pain and contracture. Based on distinct clinical and radiologic features, it is not difficult to make the diagnosis of FAVA. Earlier awareness of this disease can reduce misdiagnoses. Surgery-based comprehensive management can typically improve pain and contracture. Oral sirolimus or alpelisib plays an important role in treatment of unresectable lesions and major nerve involvement. Surgery alone can be curative in early stage FAVA.

Cryoablation for Bone and Soft Tissue Lesions in Pediatric Patients: Complications and Preventive Measures

PURPOSE

To evaluate complications associated with cryoablation in a pediatric population and review preventive measures to mitigate these complications.

MATERIAL AND METHODS

Retrospective study including all the image guided cryoablations performed on pediatric population. Immediate and delayed complications were analyzed, and we identified the different protective measures used and the clinical outcomes from follow-up. Point estimates for the percentage of complications were calculated by maximum likelihood, and 95% confidence intervals for the true percentages were calculated using the Clopper-Pearson exact method.

RESULTS

Eighty-seven ablations were performed on 68 patients (age range of 2-18 years, mean 12.4 years) for non-neoplastic (70%) and neoplastic (30%) lesions. The percentage of ablations resulting in complications was 18% (95% confidence interval (CI) 11% to 28%). Of these, 5% (95% CI 1% to 11%) were grade 3 complications, and 14% (95% CI 7% to 23%) were grade 2 complications. Thermal protection was performed in 27.6% of ablations (n = 24). The mean clinical follow-up duration was 348 days.

CONCLUSION

Cryoablation in pediatric patients is relatively safe, with a major complication rate per ablation of 5%. Thermal protective measures can be considered to mitigate these complications.

Fibro-Adipose Vascular Anomaly (FAVA): Not Another Vascular Anagram

Background. Fibro-adipose vascular anomaly (FAVA) is a rare benign mesenchymal lesion. Characterized primarily by intramuscular vascular malformation with secondary overgrowth of other mesenchymal elements, particularly fibro-adipose tissue, the condition is sometimes complicated by nonspecific clinical and imaging features, causing diagnostic dilemma. Herein, we attempted to outline and correlate the clinical characteristics, imaging findings, and histopathological features of this unusual entity. Method. The study design was retrospective in nature. Computerized database of our institute was searched for tumors, and archived slides were reviewed. Pertinent clinical data including imaging findings and treatment details were also recovered for correlation. Result. Among total of 24 patients identified, mean age was approximately 16 years, with the presence of nearly equal gender distribution. Pain along with swelling was most common symptoms with the presence of movement limitation, in few. Most lesions were long-standing and anatomically confined to lower limb with no side predilection. Using imaging, the majority of the lesions were identified as vascular anomaly or venous malformation, with FAVA being a differential diagnosis in few lesions. However, in a couple of patients, likelihood of mesenchymal tumors was also suggested, radiologically. On histology, the lesions showed the presence of clustered back to back, abnormal thin-walled, variably dilated, blood-filled sac-like vessels amid skeletal muscle bundles, along with extensive fibro-adipose tissue and variably atrophic skeletal muscle bundles, at the periphery, diagnostic of FAVA. Conclusion. Owing to the presence of overlapping clinical and imaging features, FAVA is often misdiagnosed, causing dilemma in clinical management. Clinical, radiological, and histopathological correlation is thereby warranted for clinching the correct diagnosis.

Contemporary management of extracranial vascular malformations

Vascular malformations are congenital vascular anomalies that originate because of disorganized angiogenesis, most commonly from spontaneous somatic genetic mutations. The modern management of vascular malformations requires a multidisciplinary team that offers patients the gamut of medical, surgical, and percutaneous treatment options with supportive care. This manuscript discusses the standard and contemporary management strategies surrounding extracranial vascular malformations and overgrowth syndromes.

Radiomics-based machine learning approach in differentiating fibro-adipose vascular anomaly from venous malformation

BACKGROUND

As a complex vascular malformation, fibro-adipose vascular anomaly was first proposed in 2014. Its overlap with other vascular malformations regarding imaging and clinical features often leads to misdiagnosis and improper management.

OBJECTIVE

To construct a radiomics-based machine learning model to help radiologists differentiate fibro-adipose vascular anomaly from common venous malformations.

MATERIALS AND METHODS

We retrospectively analyzed 178 children, adolescents and young adults with vascular malformations (41 fibro-adipose vascular anomaly and 137 common vascular malformation cases) who underwent MRI before surgery between May 2012 to January 2021. We extracted radiomics features from T1-weighted images and fat-saturated (FS) T2-weighted images and further selected features through least absolute shrinkage and selection operator (LASSO) and Boruta methods. We established eight weighted logistic regression classification models based on various combinations of feature-selection strategies (LASSO or Boruta) and sequence types (single- or multi-sequence). Finally, we evaluated the performance of each model by the mean area under the receiver operating characteristics curve (ROC-AUC), sensitivity and specificity in 10 runs of repeated k-fold (k = 10) cross-validation.

RESULTS

Two multi-sequence models based on axial FS T2-W, coronal FS T2-W and axial T1-W images showed promising performance. The LASSO-based multi-sequence model achieved an AUC of 97%±3.8, a sensitivity of 94%±12.4 and a specificity of 89%±9.0. The Boruta-based multi-sequence model achieved an AUC of 97%±3.7, a sensitivity of 95%±10.5 and a specificity of 87%±9.0.

CONCLUSION

The radiomics-based machine learning model can provide a promising tool to help distinguish fibro-adipose vascular anomaly from common venous malformations.

Successful treatment of fibro-adipose Vascular Anomaly with sirolimus

BACKGROUND

The purpose of this study was to present our initial experience in using sirolimus therapy to treat fibro-adipose vascular anomaly (FAVA).

METHODS

We retrospectively reviewed the medical records of eight patients with FAVA who were treated with sirolimus at our hospital between July 2017 and October 2020.

RESULTS

Six girls (75%) and two boys (25%) were included in the cohort; the average age was 8 years (range, 1-13 years). Vascular tumors developed mainly on the extremities, including the forearm (n = 2; 25.0%), calf (n = 4; 50.0%), and thigh (n = 2; 25.0%). The predominant symptoms included swelling of the lesion (n = 8; 100%), pain (n = 7; 87.5%), contracture (n = 3; 37.5%), and phlebectasia (n = 3; 37.5%). Magnetic resonance imaging was the primary method used for FAVA diagnosis, and all patients underwent enhanced MRI. All lesions were heterogeneous with hyperintense T1 signals. The fat-suppressed T2-weighted images also revealed heterogeneous hyperintense masses, thus indicating fibrofatty infiltration. All eight patients received a sirolimus treatment regimen after FAVA diagnosis. One patient underwent tumor resection but experienced recurrence, whereas the other six patients underwent biopsy. Histological examination revealed that the lesions consisted of fibrofatty tissue with abnormal venous channels and anomalous lymphatic vascular components. Sirolimus softened the masses and caused tumor shrinkage within 5.25 ± 2.6 weeks (range, 2-10 weeks) after treatment initiation. The tumors also involuted rapidly and became stable within 7.75 ± 2.25 months after treatment initiation (range, 6-12 months). All seven patients experiencing pain reported relief within 3.8 ± 1.8 weeks (range, 2-7 weeks) after initiation of sirolimus therapy. Sirolimus alleviated but did not fully resolve the contracture in three patients. Remarkably, five patients exhibited a complete response, and three patients exhibited a partial response. At the time of the last follow-up, three patients had begun to gradually taper off sirolimus after 24 months of treatment and maintained a low blood sirolimus concentration. No serious adverse effects were observed during treatment.

CONCLUSION

FAVA is a complex vascular malformation that appears to respond well to sirolimus treatment. Thus, sirolimus may be an effective and safe treatment for FAVA.

LEVEL OF EVIDENCE

LEVEL IV.

Fibro-Adipose Vascular Anomaly: Characteristic Imaging Features on Sonography and Magnetic Resonance Imaging

OBJECTIVE

To analyse the image characteristics of fibro-adipose vascular anomaly (FAVA) and the value of ultrasound and magnetic resonance imaging (MRI) for its diagnosis.

METHODS

The clinical and imaging data characteristics of 10 patients with FAVA admitted to our hospital between January 2018 and December 2020 who underwent ultrasound and MRI diagnosis were retrospectively analysed.

RESULTS

A total of 10 patients (six males and four females) with pathologically confirmed FAVA, aged from 3 to 27 years (median: 13 years), underwent ultrasound and MRI; of these, two patients underwent MRI-enhanced examinations. All lesions involved mainly muscle, with a few disruptions and involvements of subcutaneous fat. Five cases were located subcutaneously near the fascia; one case was adjacent to the periosteum. Ultrasound showed fascial tail in seven cases, and MRI showed fascial tail in six cases. Both ultrasound and MRI showed the lesions to be oval-shaped masses with blurred borders and a mean maximum diameter of 99.8 ± 48.7 mm. Ultrasound showed a mass with a mixture of high and low echoic areas. Magnetic resonance imaging imaging showed a heterogeneous, mixed-signal intensity on T1-weighted images, probably influenced by the fibrous and fatty components of the lesion. T2-weighted images showed a mixed-high signal. Enhanced computed tomography scans showed significant heterogeneous enhancement of the lesions.

CONCLUSION

Both ultrasound and MRI showed that fascial tail sign is an important imaging feature for FAVA disease; this provides a reliable basis for its diagnosis and can be used to distinguish it from venous malformations, which have no fascial tail signs. Therefore, fascial tail signs can be used as imaging features and require special attention in the diagnosis of FAVA disease.

Cut and cure: surgical therapy of synovitis

Surgical management for synovitis has undergone radical change in the last few years with the evolution of DMARDs and advanced Interventional Radiology techniques. Here we present areas where surgical therapy may still be the most effective option, either alone or in conjunction with non-surgical measures.

Vascular anomalies: clinical perspectives

Vascular anomalies are classified as vascular tumors or vascular malformations according to their cellular features and biological behavior. Detailed history and clinical assessment allow for the proper clinical diagnosis of most vascular anomalies and guide the choice of imaging to evaluate them. This article discusses the general information needed from a clinical history and physical exam to formulate a diagnosis of vascular anomaly. Then, the authors review the clinical findings from the most common vascular tumors and vascular malformations.

Case Report of Fibro-Adipose Vascular Anomaly (FAVA) with Activating Somatic PIK3CA Mutation

Fibro-adipose vascular anomaly (FAVA) is a recently described complex and painful benign lesion found in young adults and the pediatric population composed of intramuscular vascular, fibrous, and adipose tissues. A previous report has identified the presence of somatic mosaic mutations in the gene for the catalytic subunit of phosphatidylinositol 3-kinase (PIK3CA) in cases of FAVA. Herein, we present a case of FAVA found in a 23-year-old male patient who presented with chronic wrist pain associated with a mass, and we identified an associated somatic activating mutation (H1047R) in PIK3CA. We briefly review the relevant literature surrounding the identification and histology of FAVA, the known mutational spectrum, downstream signaling pathways, and relevant treatment modalities. Our case highlights the association between FAVA and somatic mosaic activating PIK3CA mutations.

Fibroadipose Vascular Anomaly of the Upper Extremity: Case Report of Extensive Resection and Secondary Tendon Transfer

ABSTRACT

Alomari and colleagues described in 2014 for the first time a distinct combination of vascular malformation, fibrofatty muscular infiltration and contracture which was termed fibroadipose vascular anomaly (FAVA) (J Pediatr Orthoped 34, 109-117 (2014). So far only few publications (J Pediatr Orthoped (2014) 34, 109-117; J Hand Surg (2020). 45, 68.e1, 68.e13; Ann Vasc Dis (2014) 7, 316-319; Pediatr Radiol 46, 1179-1186 (2016)) concerning this newly described disease have been published, covering only a limited number of cases. We present a case of a 19-year-old male patient suffering from a FAVA of the proximal forearm with a severe contracture of the infiltrated flexor musculature. Upon surgery, we observed infiltration of the ulnar nerve. We were able to successfully resect the vascular malformation. Secondary tendon transfer was performed after extensive resection of the flexor musculature.FAVA presents a differential diagnosis in patients with solid growth of the upper or lower extremity and contracture of the involved extremity. We conclude that patients suffering from FAVA of the upper extremity should be referred to a center specialized in oncologic extremity surgery and reconstructive hand and microsurgery.

Newcomers in Vascular Anomalies

Vascular anomalies are composed of tumors and malformations and with overlapping histologies, thus are often misdiagnosed or labeled with imprecise terminology. Lesions are common and usually diagnosed during infancy or childhood; the estimated prevalence is 4.5%. Vascular tumors rapidly enlarge postnatally and demonstrate endothelial proliferation. Malformations are errors in vascular development with stable endothelial turnover; they are typically named based on the primary vessel that is malformed (capillary, arterial, venous, lymphatic). This article reviews the pathologic and molecular genetic characteristics for select recently described vascular anomalies.

Fibro Adipose Vascular Anomaly: A Rare and Often Misdiagnosed Entity

Fibro adipose vascular anomaly (FAVA) is a rare type of vascular malformation with distinct clinical features. The authors here discussed the clinical, imaging, differential diagnosis, histopathological features, and treatment options of FAVA along with an illustrative case. It is important to know about this uncommon entity as this can be misdiagnosed due to the overlapping clinical features with other common entities. It is a benign condition with no proven malignant potential. There are no guidelines regarding the best treatment option.

Management of Fibro-adipose Vascular Anomalies (FAVA) in Paediatric Practice

Fibro-adipose vascular anomaly (FAVA) is a discrete type of vascular anomaly. We describe our experience managing FAVA at a tertiary level paediatric hospital and offer a treatment algorithm.

Methods

A retrospective review of 27 patients with proven FAVA was undertaken. All patients had undergone MRI and USS evaluation. Patient demographics, presenting concerns, treatment methods, and outcomes were recorded and evaluation with the paediatric outcomes data collection instrument (PODCI) completed a minimum of 12 months after definitive treatment.

Results

Mean age at presentation was 8.9 years (range: 9 m-17.4 y) and mean post-treatment follow-up was 7.4 y (range: 2 y-11.6 y). Twenty of 27 lesions affected the lower limb. Severe neurogenic-type pain was present in 23 cases and contractures across joints in 11 cases. Sclerotherapy with sodium tetradecyl sulphate was used in 11 cases, with no improvement in symptoms. Cryoablation provided pain relief in 3/4 cases, but contracture subsequently increased in one patient and pain recurred in another.Fourteen cases underwent surgery (four surgical excisions alone, 10 in combination with other procedures). Three patients required four further surgical procedures that include one amputation for intractable pain and poor function.PODCI evaluations suggest overall good function, with surgical management and interventional radiology that provide comparable results. Surgery did correct deformity.

Conclusion

If conservative measures or cryoablation fail to achieve symptomatic control, surgical excision should be considered, combined with adjunctive procedures, to correct contractures and balance muscle forces.Relief of pain may compensate for the loss of muscle mass and overall improves function. Multidisciplinary team working is essential.

Ultrasound Evaluation of Pediatric Slow-Flow Vascular Malformations: Practical Diagnostic Reporting to Guide Interventional Management

OBJECTIVE. This article reviews the ultrasound characteristics of pediatric slow-flow vascular malformations and underscores findings that significantly impact diagnosis and treatment. Key imaging features are discussed including lesion size, malformation location, morphology, and mimics. CONCLUSION. Ultrasound findings affect the management of slow-flow vascular malformations and should be emphasized in lesion diagnosis. Superficial, focal lesions with well-defined margins are ideal for ultrasound evaluation.

Vascular anomalies: special considerations in children

The diagnosis and treatment of vascular anomalies are a large part of the caseload for paediatric interventional radiologists. Although many of the principles of sclerotherapy and embolisation are the same in adult and paediatric practice, there are some key differences in the approach for children, including some longer term thinking about managing these chronic diseases and their impact on a growing child. Vascular tumours are not often seen in adult IR practice and the rarest can be life threatening; knowledge of the commonest types and the role IR can play in their management can be instrumental in ensuring that children get appropriate treatment in a timely manner. Vascular anomalies also encompass some conditions associated with complex overgrowth, a subject that often causes confusion and uncertainty for interventional radiologists. This paper presents a simplified and practical approach to this spectrum of disease.

Overgrowth syndromes and new therapies

Overgrowth syndromes represent a diverse group of disorders with overlapping features. Interdisciplinary management by a team of experts in vascular anomalies is crucial for establishing the correct diagnosis and optimizing outcomes for these patients. Unique management considerations include increased risk for thrombosis and in some cases, cancer. In recent years, research has demonstrated that these disorders are primarily caused by somatic mutations in growth pathways, particularly the PI3K-mTOR pathway. This improved understanding had led to promising new therapies for this group of patients.

Hybrid treatment of fibroadipose vascular anomaly: A case report

Background

First identified in 2014, fibroadipose vascular anomaly (FAVA) is a very rare type of venous and lymphatic malformation. Marked by tough fibrofatty tissue in the extremities overtaking portions of the muscles, it is associated with constant pain and contracture of the affected extremity. There is a paucity of literature, and no guidelines on treatment procedure are available. This case highlights the role of hybrid treatment with primary ethanol percutaneous ethanol embolization and additional surgery for radicality in excision of FAVA lesions.

Case summary

A 9-year-old girl with FAVA underwent the hybrid treatment. The achievements of complete excision, clinical response, and patient satisfaction in long-term follow-up were assessed. Following the hybrid treatment, the patient experienced significant improvement in pain. Concurrent symptoms of physical limitation, leg swelling, and skin hyperesthesia also improved. The clinical benefit, supported by postoperative physiotherapy, was well stabilized at 6-month follow-up, resulting in complete patient satisfaction at 12- and 36-month follow-ups. No major complications were encountered.

Conclusion

Ethanol embolization plus surgery is a safe, effective, and long-term hybrid treatment of symptomatic FAVA lesions.

Rapid prototyping of custom radiocontrast agent markers for computed tomography-guided procedures

The objective of this study was to evaluate a method for printing a custom radiocontrast agent mixture to develop computed tomography markers of various shapes and sizes for assisting physicians in computed tomography-guided procedures. The radiocontrast agent mixture was designed to be bright in a computed tomography image, able to be extruded from a nozzle as a liquid and transition into a solid, and sufficiently viscous to be extruded through the tip of a needle in a controlled manner. A mixture printing method was developed using a syringe to house the mixture, a syringe pump to extrude the mixture, and a computer numeric control laser cutter to direct the nozzle in the desired path. To assess the efficacy of printing the radiocontrast agent mixture, we printed several designs, collected computed tomography images, and evaluated various physical properties of the printing method and the resulting computed tomography markers. The average line thickness was 1.56 mm (standard deviation of 0.19 mm, n = 30), the infill percentage was 99.9%, and the deviation in roundness was 0.23 mm (n = 30). These results demonstrated the ability of the proposed method to create various types of skin markers, such as dots, lines, and hollow or solid shapes. Additionally, flat printed patterns can be folded to form three-dimensional structures that can be used to guide and support needle insertions.

Fibro-adipose vascular anomaly (FAVA): three case reports with an emphasis on the mammalian target of rapamycin (mTOR) pathway

BACKGROUND

Fibro-adipose vascular anomaly (FAVA) is a new entity of vascular anomalies with somatic and mosaic gain-of-function mutations of the phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA). PIK3CA mutation excessively activates mammalian target of rapamycin (mTOR) pathway, which promotes angiogenesis and lymphangiogenesis. Histologically, FAVA is composed of intramuscular fibrous and adipose tissues with venous malformation (VM). Although sirolimus known as a mTOR inhibitor has good response to FAVA, expression pattern of the mTOR pathway was still unclear. Herein, we immunohistochemically investigated three novel FAVA patients with an emphasis on the mTOR pathway (p-S6K1, p-4EBP1 and p-AKT).

CASE PRESENTATION

Case 1: A 10-year-old female had complained of pain in the left thigh since she was 6-year-old. Under the clinical diagnosis of VM, she underwent surgical resection for the lesion. Case 2: A 29-year-old female patient had complained of discomfort and mild pain in the left shoulder since she was 18-year-old. After childbirth, she had severe ongoing pain and contracture of the shoulder. Under clinical diagnosis of VM, surgical resection was performed. Case 3: A 53-year-old female had complained of pain and knee restriction after surgical treatment of a knee tumor at the age of 31. Under the clinical diagnosis of atypical lipomatous tumor or high grade liposarcoma, surgical resection was performed. Histologically, all three patients presented with characteristic features of fibrous and adipose tissues with abnormal vessels within the skeletal muscle, leading to diagnosis of FAVA. Although VM has been reported as an important finding in FAVA, immunohistological findings demonstrated that abnormal vessels comprised complex of VM and lymphatic malformation (LM) in all cases. Furthermore, besides vascular malformation, abnormal fibrous and adipose tissues of FAVA expressed mTOR pathway components.

CONCLUSIONS

We presented three new cases of FAVA. Histological and immunohistochemical analyses revealed that VM and LM complex was an important finding in FAVA, and that the mTOR pathway components were expressed in abnormal fibrous tissue, adipose tissue and vascular malformation. These findings suggested that FAVA might be a mesenchymal malformation caused by PI3K/AKT/mTOR pathway.

Three Distinct Vascular Anomalies Involving Skeletal Muscle: Simplifying the Approach for the General Radiologist

Venous malformations and hemangiomas of the skeletal muscle are separate entities with different clinical presentation, histology, and imaging findings. Recent advances in the field of vascular anomalies and current efforts in the unification of terminology by the International Society for the Study of Vascular Anomalies are pivotal in understanding and differentiating intramuscular venous malformations and intramuscular capillary-type hemangioma. Fibroadipose vascular anomaly is another recently defined vascular anomaly affecting the skeletal muscle, with a distinct clinical presentation, histology, and imaging appearance. These 3 distinct vascular anomalies are reviewed and their histologic features, clinical presentation, imaging appearance, and treatment are discussed.

Percutaneous MR-Guided Cryoablation of Low-Flow Vascular Malformation: Technical Feasibility, Safety and Clinical Efficacy

PURPOSE

To retrospectively assess the technical feasibility, safety and clinical efficacy of percutaneous MR-guided cryoablation of low-flow vascular malformations (LFVM).

MATERIALS AND METHODS

Between July 2013 and May 2019, 9 consecutive patients (5 male; 4 female; mean age 39.4 ± 15.3 years, range 15-68) underwent MR-guided cryoablation of LFVM. Patients were treated due to pain in all cases. Procedural data, complications and clinical results were analyzed.

RESULTS

Technical success defined as complete coverage of the LFVM by the iceball without involvement of nearby non-target thermal-sensitive structures was achieved in 9/9 (100%) cases. Mean procedure time was 122 ± 20 min (range 90-150); 2-6 cryoprobes (mean 3.7 ± 1.2) and 2-4 freezing cycles (mean freezing time 19.8 ± 11.8 min; range 4-40) were applied. No complications were noted. Mean time from the first treatment to the last follow-up was 548 days (range 30-1776). Persistent/recurring pain was noted in 3/9 cases (33%) 30, 133 and 639 days after cryoablation, respectively, and was related in all cases to MR-confirmed local residual/recurring disease. A second cryoablation treatment was performed in these 3 cases with complete pain control at the last available follow-up (153, 25, 91 days, respectively). In the whole population, at mean 161 days (range 25-413) after the last treatment, on the numerical pain rate scale, pain significantly dropped from mean 6.4 ± 2.1 (range 3-9/10) before CA to mean 0.3 ± 0.9 (range 0-3/10) after (p = 0.009).

CONCLUSIONS

Percutaneous MR-guided cryoablation is technically feasible, safe and effective for the treatment of symptomatic LFVM.

LEVEL OF EVIDENCE

Level 3b, retrospective cohort study.

Congenital Limb Overgrowth Syndromes Associated with Vascular Anomalies

Congenital limb length discrepancy disorders are frequently associated with a variety of vascular anomalies and have unique genetic and phenotypic features. Many of these syndromes have been linked to sporadic somatic mosaicism involving mutations of the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, which has an important role in tissue growth and angiogenesis. Radiologists who are aware of congenital limb length discrepancies can make specific diagnoses based on imaging findings. Although genetic confirmation is necessary for a definitive diagnosis, the radiologist serves as a central figure in the identification and treatment of these disorders. The clinical presentations, diagnostic and imaging workups, and treatment options available for patients with Klippel-Trenaunay syndrome, CLOVES (congenital lipomatous overgrowth, vascular anomalies, epidermal nevi, and scoliosis/spinal deformities) syndrome, fibroadipose vascular anomaly, phosphatase and tensin homolog mutation spectrum, Parkes-Weber syndrome, and Proteus syndrome are reviewed. ^©RSNA, 2019.

Clinical and imaging features in fibro-adipose vascular anomaly (FAVA)

BACKGROUND

Fibro-adipose vascular anomaly (FAVA) is a rare and recently described complex vascular malformation. The clinical and imaging features and morphology can be confusing and often overlap with features of other vascular malformations and tumors.

OBJECTIVE

To present the imaging characterization of FAVA in association with clinical features.

MATERIALS AND METHODS

We retrospectively evaluated clinical and imaging (MRI, sonography and venography) findings in FAVA. We documented the clinical presentation, lesion morphology, imaging characteristics, tissue distribution, pattern of contrast enhancement and vascular characteristics.

RESULTS

Thirty-eight people (31 female, 7 male) ages 1-30 years (mean 12 years) were diagnosed with FAVA based on clinical findings combined with imaging or histopathological findings (n=17). Most lesions were in the lower extremity (n=36). Three patterns were noticed: focal, focal infiltrative and diffuse.

CONCLUSION

Fibro-adipose vascular anomaly, a rare and complex vascular malformation, has distinct clinical and imaging features that a radiologist should be familiar with to avoid delay in diagnosis and to direct appropriate management.

Surgical Management of Fibroadipose Vascular Anomaly of the Lower Extremities

BACKGROUND

Fibroadipose vascular anomaly (FAVA) is a recently-defined vascular malformation often involving the extremities and presenting in childhood. Patients may present to orthopaedic surgeons with pain, swelling, joint contractures, and leg length discrepancy. There is no established therapy or treatment paradigm. We report on outcomes following surgical excision for patients with this condition.

METHODS

Between 2007 and 2016, all 35 patients that underwent excision of lower-extremity FAVA were retrospectively reviewed using a combination of medical records, radiologic findings, and telemedicine reviews.

RESULTS

Mean age at initial presentation was 12.3±6.8 years. Mean follow-up from time of definitive diagnosis at our institution was 66 months (range: 12 to 161 mo). Mean follow-up after surgery was 35 months (range: 6 to 138 mo). Females were affected more than males (71% vs. 29%). The most common location of FAVA was in the calf (49%), followed by the thigh (40%). The most commonly involved muscle was gastrocnemius (29%), followed by the quadriceps (26%). At latest follow-up after surgery, there was an improvement in the proportion of patients with pain at rest (63% vs. 29%), pain with activity (100% vs. 60%), as well as analgesia use (94% vs. 37%). Fourteen patients (40%) had symptomatic residual disease or recurrence of FAVA requiring further treatment. Six patients (17%) required further surgery and 6 (17%) required further interventional radiologic procedures. Three patients (9%) required eventual amputation for intractable pain and loss of function. Lesions with direct nerve involvement were associated with persistent neuropathic symptoms at latest follow-up (P=0.002) as well as symptomatic residual disease and/or recurrence requiring further treatment (P=0.01). Seventeen patients (49%) had 19 preoperative joint contractures. Eighteen of the 19 contractures (95%) had sustained improvement at latest follow-up.

CONCLUSIONS

In carefully selected patients, surgical excision of FAVA results in improvement of symptoms. However, symptomatic residual disease and/or recurrence are not uncommon. Direct nerve involvement is associated with a worse outcome.

LEVEL OF EVIDENCE

Level IV-case series.

Percutaneous Cryoablation of Symptomatic Intramuscular Venous Malformation

PURPOSE

To evaluate the efficacy and safety of cryoablation for venous malformations.

MATERIALS AND METHODS

A total of 12 patients with symptomatic intramuscular venous malformations who underwent percutaneous cryoablation between February 2015 and December 2018 were retrospectively studied. The mean age was 42 y (range, 19-58 y). Pain was reported by 11 patients (92%) and swelling by 1 (8%). Pain was assessed with a visual analog scale (VAS) before and after cryoablation. Lesion size was followed with magnetic resonance (MR) imaging at baseline and at 3-mo follow-up. Median initial VAS score was 7 (range, 0-8), and median initial lesion size was 32.5 mm (range, 11-150 mm).

RESULTS

The median VAS score at 3 mo was 0 (range, 0-4), and the median lesion size at 3 mo was 0 mm (range, 0-142 mm). Eleven of 12 patients reported an improvement in their pain. MR imaging control showed a treatment scar with no residual lesion in 5 patients and decreased lesion size in 4. No major complications were reported. One minor hematoma and 1 small myositis were noted as defined by Society of Interventional Radiology criteria.

CONCLUSIONS

Percutaneous cryoablation is effective and safe for treatment of symptomatic intramuscular venous malformations, with improvement of symptoms.

Lower Extremity Fibro-Adipose Vascular Anomaly-Case Report

Fibro-adipose vascular anomaly (FAVA) is a painful complex vascular malformation, characterized by muscle fibrofatty infiltration, usually in lower limb, associated with contracture of the ipsilateral extremity. This article describes the first case of FAVA reported in Portugal successfully treated with surgery. A 9-year-old female was admitted complaining of a painful mass in the right leg. The MRI scan showed the presence of a 5 × 4 × 4 cm mass in the right leg consistent with FAVA located in the peroneus longus muscle. The patient underwent resection of the involved muscle. She had 6 months of follow-up without any relevant clinical event. The authors also highlight the difference between FAVA and venous malformation. Early surgery is a treatment option that can prevent long-term consequences, as contracture and movement limitation.

Cryoablation of low-flow vascular malformations

PURPOSE

We aimed to evaluate the safety and effectiveness of cryoablation in the treatment of low-flow malformations, specifically venous malformation (VM) and fibroadipose vascular anomaly (FAVA).

METHODS

We conducted a retrospective review of 11 consecutive patients with low-flow malformations (14 lesions; 9 VM, 5 FAVA), median lesion volume 10.8 cm3, (range, 1.8-55.6 cm3) with a median age of 19 years (range, 10-50 years) who underwent cryoablation to achieve symptomatic control. Average follow-up was at a median of 207 days postprocedure (range, 120-886 days). Indications for treatment included focal pain and swelling. Technical success was achieved if the cryoablation ice ball covered the region of the malformation that corresponded to the patient's symptoms. Clinical success was considered complete if all symptoms resolved and partial if some symptoms persisted but did not necessitate further treatment.

RESULTS

The technical success rate was 100%. At 1-month follow-up, 13 of 14 lesions (93%) had a complete response and one (7%) had a partial response. At 6-month follow-up 12 of 13 (92%) had a complete response and 1 (8%) had a partial response. A total of 6 patients underwent primary cryoablation. Out of 9 VM cases, 7 had prior sclerotherapy and 2 had primary cryoablation. Out of the 5 FAVA cases, 1 had prior sclerotherapy and the remaining 4 cases underwent primary cryoablation. There were 3 minor complications following cryoablation including 2 cases of skin blisters and 1 case of transient numbness. These complications resolved with conservative management.

CONCLUSION

Cryoablation is safe and effective in the treatment of low-flow vascular malformations, either after sclerotherapy or as primary treatment.

Brief Description of ISSVA Classification for Radiologists

Ongoing discovery regarding the origin and treatment of vascular anomalies requires standardized nomenclature which itself must undergo iterative updating. This article introduces the 2018 International Society for the Study of Vascular Anomalies (ISSVA) classification, emphasizing the biologic basis of vascular anomalies, summarizing the key features of commonly encountered entities, and serving as a foundation for subsequent articles presented herein. Vascular tumors are discussed to highlight their distinction from vascular malformations which will receive greater attention with respect to management and technical considerations within the issue.

Vascular anomalies of the upper limb

Vascular anomalies are common in the upper extremities, but there continues to be a relative paucity of information about them in publications dealing with surgery in the hands and upper limbs. The wide spectrum of pathology and an inconsistent use of terminology make vascular anomalies susceptible to incorrect diagnosis and as a result, to misdirected management. This article aims to provide an update on vascular anomalies relevant to the upper limbs, focusing on significant advances in pathogenesis and genetics, classification systems, diagnosis and treatment.

Soft-tissue vascular malformations and tumors. Part 2: low-flow lesions

Vascular malformations and tumors, also known as "vascular anomalies", comprise an extensive variety of lesions involving all parts of the body. Due to a lack of a complete understanding of the origin and histopathology of such lesions, this field has been traditionally obscured by the use of an unclear nomenclature. Knowledge of the classification and clinical and imaging characteristics of this group of lesions is paramount when managing these patients. The objective of this series of two articles is to review the current classification of vascular anomalies, to describe the role of imaging in their diagnosis, to summarize their distinctive histopathologic, clinical and imaging features, and to discuss the treatment options. High-flow lesions were discussed in the first article of this series. In this second article, we will focus on low-flow lesions, including complex syndromes with associated low-flow malformations.

Fibroadipose vascular anomaly treated with sirolimus: Successful outcome in two patients

Fibroadipose vascular anomaly (FAVA) is a rare, complex mesenchymal malformation combining fibrofatty replacement of the affected muscles and slow-flow vascular malformation. The condition is characterized by localized swelling, severe pain, phlebectasia, and contracture of the affected limb. Treatment paradigms are not well established for this rare, recently recognized condition. We report two cases of FAVA in which treatment with sirolimus produced rapid, dramatic improvement in pain and quality of life.

Late sequelae and long-term outcomes of vascular anomalies

Vascular anomalies are classified as tumors and malformations depending on their clinical characteristics, pathological diagnosis and recent genomic information. Diagnosis can still be challenging because of the heterogeneity of clinical presentation. Thus, the best care is provided by an interdisciplinary team of specialists. An updated classification system has helped provide more consistent terminology with the addition of new diagnoses and genomic discovery. Historically, treatment of vascular anomalies was primarily surgical and or interventional with limited medical therapies. The field of vascular anomalies lacked prospective clinical trials in both medical treatments as well as surgical and interventional therapeutic options. Recent interdisciplinary collaboration has led to collaborative studies in which short- and long-term outcomes are being prospectively evaluated. Specifically, discoveries of pharmacologic agents effective in treating vascular anomalies have broadened our medical therapeutic options, which has led to innovative approaches in combined treatment of vascular anomalies and has stressed the need to prospectively assess long-term outcomes and sequelae for these patients which has been lacking in this field.

Percutaneous Image-Guided Cryoablation in Vascular Anomalies

Understanding and management of vascular anomalies has always been intriguing. These disorders exhibit an expected pattern of clinical presentation and progression, and characteristic imaging findings. Significant progress in understanding and treating patients with vascular anomalies has been made in the past quarter century. Newer multidisciplinary domains for treating these disorders with medical drugs and less invasive image-guided or surgical procedures are constantly evolving. Vascular anomalies can exhibit aggressive tumor-like behavior resulting in recurrence or persistent symptoms after treatment. Thermal ablation has been widely used in tumor treatment. This has generated interest on using thermal ablation for treating vascular anomalies. Percutaneous image-guided cryoablation is increasingly used for this purpose as compared with other ablation technologies. Availability of small caliber cryoprobes and the ability to monitor the freeze zone in real time have made this an attractive option to interventional radiologists. These experiences are relatively new and limited. It is helpful to understand the emerging role of this technology in the treatment of vascular anomalies.

Percutaneous cryoablation of symptomatic venous malformations as a second-line therapeutic option: a five-year single institution experience

PURPOSE

To report the mid-term outcomes of percutaneous cryoablation (PCA) performed as second-line therapeutic option of venous malformations (VM).

MATERIAL AND METHODS

From 2011 to 2015, PCA was offered in 24 patients (mean age: 31 years, range: 12-64) as second-line treatment for recurrence of symptoms after sclerotherapy and when resection was not possible (due to lesion location or previous failure) or refused by the patient. Adverse effects were recorded, disease-free survival (DFS) and local tissue control (LTC) rates were calculated based on symptoms and volume evolution.

RESULTS

Mean follow-up was 18.7 months (6-48). Nine (37.5%, 9/24) adverse effects occurred and three (12.5%, 3/24) were severe. Mean pain assessed by visual analog scale (VAS) was 41.7 mm (0-80) before treatment and 20.3 mm (0-80) (p=0.01) after. Mean volume decreased significantly after treatment from 22.4 cm³ (0.9-146) to 8.35 cm³ (0-81.3) (p<0.001). Pain recurred in nine patients and size of one lesion increased. The DFS and LTC rates were 54% [95%CI: 22.94-77.27] and 93.33% [61.26-99.03] at 24 months, respectively. Only VM volume >10 cm³ was associated with a higher risk of local recurrence (p=0.05).

CONCLUSION

PCA as second-line treatment appears to be safe and effective for local control of VM according to mid-term results.

KEY POINTS

• Percutaneous cryoablation of venous malformations appeared well tolerated. • Size of venous malformations decreased significantly after percutaneous cryoablation (p<0.001). • Pain decreased significantly after percutaneous cryoablation of venous malformations (p=0.01).

Mid-term outcomes after percutaneous cryoablation of symptomatic abdominal wall endometriosis: comparison with surgery alone in a single institution

OBJECTIVES

To compare the outcomes of percutaneous image-guided cryoablation of symptomatic abdominal wall endometriosis (AWE) versus surgery alone.

METHODS

From 2004 to 2016, cryoablation or surgery alone was performed under local (n = 5) or general anaesthesia (n = 15) for AWE in a single institution in 7 (mean age, 36.1 years) and 13 (mean age, 31.9 years) patients, respectively. Fifteen lesions were treated by cryoablation (mean size, 2.3 cm; range, 0.5-7 cm) and 16 by surgery (2.5 cm; 1.1-3.4 cm). Tolerance, efficacy and patient and procedural characteristics were compared.

RESULTS

Median follow-up was 22.5 (range, 6-42) months after cryoablation and 54 (14-149) after surgery. The median procedure and hospitalisation durations were 41.5 min (24-66) and 0.8 days (0-1) after cryoablation, and 73.5 min (35-160) and 2.8 days (1-12 days) after surgery (both P = 0.01). Three patients (23.1%) had severe complications and nine aesthetic sequels (69.2%) after surgery, none after cryoablation (P = 0.05). The median 12- and 24-month symptom free-survival rates were 100% and 66.7% (95% CI, 5.4; 94.5) after cryoablation and 92% (55.3; 98.9) after surgery at both time points (P = 0.45).

CONCLUSIONS

Cryoablation presents similar effectiveness to surgery alone for local control of AWE while reducing hospitalisation duration and complications. Any aesthetic sequels were associated with the cryoablation treatment.

KEY POINTS

• Hospitalisation is shorter after cryoablation than after surgery of abdominal wall endometriosis. • A significantly lower rate of complications is observed after cryoablation compared to surgery. • Cryoablation of abdominal wall endometriosis presents similar effectiveness to surgery alone. • A significant reduction of pain is observed 6 months after treatment. • A significant reduction of abdominal wall endometriosis is observed at 6 months.

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.