Vascular tumors in infants and adolescents

Vulvar Hemangioma: A Review

Objectives: To review the clinical presentation, diagnostic approach, treatment strategies, and outcomes of vulvar hemangiomas, and to evaluate the consistency of management practices in the absence of standardized guidelines. Eligibility criteria: We included case reports, case series, and observational studies describing vulvar hemangiomas with clinical, histological, and management data in human subjects. Reviews, editorials, and studies unrelated to vulvar hemangiomas were excluded. Information sources: Systematic searches were conducted in PubMed, Embase, Scopus, and Web of Science up to 20 February 2025, with additional citation tracking. Results: 85 studies were included. Data were synthesized narratively due to heterogeneity in the study design and outcome reporting. Most studies described symptomatic lesions presenting as swelling, bleeding, or pain, often misdiagnosed as Bartholin cysts or varicosities. Treatment varied widely, including observation, surgical excision, embolization, and medical therapies. No evidence-based guidelines were identified. Conclusions: Vulvar hemangiomas are rare and frequently misdiagnosed. While asymptomatic lesions may be observed, symptomatic cases require individualized treatment. This review highlights the need for diagnostic vigilance and the development of standardized management protocols. Further research is needed to optimize clinical outcomes.

Retinoblastoma and beyond: pediatric orbital mass lesions

Various space occupying lesions can arise in the orbit, ranging from developmental anomalies to malignancies, and many of the diseases occurring in children are different from the pathologies in the adult population. As the clinical presentation is frequently nonspecific, radiologic evaluation is essential for lesion detection and characterization as well as patient management. While orbital masses may in some cases involve multiple compartments, a simple compartmental approach is the key for the diagnosis on imaging studies, and MRI is the modality of choice. This pictorial review presents the most common and characteristic non-emergent pediatric orbital lesions, stressing their MRI and CT appearances, including specific differentiating features. The lesions are subdivided into 4 compartments: intraocular, intraconal, extraconal, and orbital walls. Retinoblastoma, Coats disease and persistent fetal vasculature; optic pathway glioma and lymphovascular malformations; rhabdomyosarcoma, infantile hemangioma, neurofibroma and lymphoma; neuroblastoma, leukemia/myeloid sarcoma, Langerhans cell histiocytosis and dermoid are reviewed in their respective compartments.

Recent advances in understanding the molecular basis of infantile haemangioma development

Infantile haemangioma (IH) - the most common vascular tumour of infancy - is comprised of diverse cell types, including endothelial cells, pericytes, fibroblasts and immune cells. IH is characterized by rapid proliferation followed by slow involution over 1-10 years. Most lesions regress spontaneously, but up to 10% can be disfiguring, with complications that require further medical treatment. Recent research has revealed the biological characteristics of IH, highlighting the involvement of angiogenesis and vasculogenesis during tumour formation. Gene expression profiling has provided vital insights into the underlying biological processes, with some of the key IH-related pathways identified, including vascular endothelial growth factor, the renin-angiotensin-aldosterone system, hypoxia-inducible factor 1α, Notch, platelet-derived growth factor, phosphoinositide 3-kinase/Akt/mammalian target of rapamycin, Janus kinase/signal transducers and activators of transcription, fibroblast growth factor, peroxisome proliferator-activated receptor-γ and insulin-like growth factor. Further evidence suggests extracellular matrix factors and hormone receptors regulate IH progression. In this review, we explore the molecular mechanisms involved in the proliferating, plateau and involuting phases of IH, identifying differentially expressed genes, targeted proteins and key signalling pathways. This knowledge will increase the broader understanding of vascular development, tissue remodelling and angiogenesis.

Outcome of bleomycin electrosclerotherapy of slow-flow malformations in adults and children

OBJECTIVES

To evaluate the safety and clinical outcome of bleomycin electrosclerotherapy (BEST) for treating extracranial slow-flow malformations.

METHODS

In this retrospective investigation of a multicenter cohort presenting symptomatic slow-flow malformations, patient records were analyzed with respect to procedural details and complications. A treatment-specific, patient-reported questionnaire was additionally evaluated, obtained 3-12 months after the last treatment, to assess the subjective outcomes, including mobility, aesthetic aspects, and pain, as well as the occurrence of postprocedural skin hyperpigmentation. All outcome parameters were compared according to patients' age.

RESULTS

Overall, 325 BEST treatments were performed in 233 patients after intralesional and/or intravenous bleomycin injection. The total complication rate was 10.2% (33/325), including 29/352 (8.9%) major complications. Patient-reported mobility decreased in 10/133 (8.8%), was stable in 30/113 (26.5%), improved in 48/113 (42.5%), and was rated symptom-free in 25/113 (22.1%) patients. Aesthetic aspects were rated impaired compared to baseline in 19/113 (16.8%), stable in 21/133 (18.6%), improved in 62/113 (54.9%), and perfect in 11/133 (9.7%) patients. Postprocedural skin hyperpigmentation occurred in 78/113 (69%) patients, remaining unchanged in 24/78 (30.8%), reduced in 51/78 (65.5%), and completely resolved in 3/78 (3.8%) patients. The median VAS pain scale was 4.0 (0-10) preprocedural and 2.0 (0-9) postprocedural. Children/adolescents performed significantly better in all parameters compared to adults (≥ 16 years) (mobility, p = 0.011; aesthetic aspects, p < 0.001; pain, p < 0.001).

CONCLUSIONS

BEST is effective for treating slow-flow vascular malformations, with few but potentially significant major complications. Regarding patient-reported outcomes, children seem to benefit better compared to older patients, suggesting that BEST should not be restricted to adults.

CLINICAL RELEVANCE STATEMENT

Bleomycin electrosclerotherapy is a safe and effective approach and therapy should not be restricted to adults due to good clinical outcomes in children.

Insights into the mechanisms of angiogenesis in infantile hemangioma

Infantile hemangioma (IH) is the most common benign tumor in infants and usually resolves on its own. However, a small portion of IH cases are accompanied by serious complications and other problems, impacting the physical and psychological health of the children affected. The pathogenesis of IH is highly controversial. Studies have shown that abnormal blood vessel formation is an important pathological basis for the development of IH. Compared with that in normal tissues, the equilibrium of blood vessel growth at the tumor site is disrupted, and interactions among other types of cells, such as immune cells, promote the rapid proliferation and migration of vascular tissue cells and the construction of vascular networks. Currently, propranolol is the most common systemic drug used to inhibit the growth of IHs and accelerate their regression. The purpose of this review is to provide the latest research on the mechanisms of angiogenesis in IH. We discuss the possible roles of three major factors, namely, estrogen, hypoxia, and inflammation, in the development of IH. Additionally, we summarize the key roles of tumor cell subpopulations, such as pericytes, in the proliferation and regression of IH considering evidence from the past few years, with an emphasis on the possible mechanisms of propranolol in the treatment of IH. Angiogenesis is an important event during the development of IH, and an in-depth understanding of the molecular mechanisms of angiogenesis will provide new insights into the biology and clinical treatment of IH.

Clitoral Hemangioma in Adults: A Case Report and Literature Review

Hemangiomas are benign vascular tumors commonly seen in early childhood, typically occurring on the face, scalp, chest, or back. Clitoral hemangiomas, especially in adults, are exceptionally rare. This case report describes a unique presentation of clitoromegaly due to a cavernous hemangioma of the clitoris in a 39-year-old woman who presented with a progressive and worsening swelling of the clitoris for five years. A surgical excision of the cyst was performed, and a histological examination confirmed a cavernous hemangioma.

Imaging of Vascular Anomalies

Vascular anomalies (VAs) are a heterogeneous group of vascular malformations and tumors that are frequently encountered in daily practice. While most are benign, malignant vascular tumors exist, as do other nonvascular soft-tissue malignancies that may masquerade as a benign VA. The subtleties of arriving at an accurate diagnosis can be intimidating, as new entities are described and names of conditions have been modified. Therefore, the goal of this article is to describe the classic imaging findings of VAs so that the interventional radiologist can confidently and competently contribute to management decisions, with special attention to ominous imaging features that should prompt biopsy or further imaging workup.

Suspected Symptomatic Infected Native Aortic Aneurysm Turns Out To Be Aortic Tumour Originating From Metastatic Cancer of Unknown Primary: A Case Report and Review of Literature

Introduction

The non-specific clinical presentation of a primary aortic tumour may mimic infectious processes. Together with its rarity, this resemblance can complicate timely identification and pose diagnostic challenges.

Report

The case of a 77 year old male patient complaining of abdominal pain radiating to the back, fatigue, and loss of appetite for a month, is presented. Contrast enhanced computed tomography showed a 47 mm infrarenal aortic aneurysm with peripheral enhancement. With suspicion of an infected native aortic aneurysm, open aortic repair was performed using a bovine pericardial Y prosthesis. The intra-operative biopsy revealed a malignant undifferentiated neoplasm, which later turned out to originate from metastatic cancer of unknown primary. The patient died six months later following comprehensive and extensive oncological treatment, which included radiotherapy and chemotherapy.

Discussion

Given the scarcity of literature and challenges in classification, treatment recommendations rely on a multidisciplinary approach, involving surgery, radiotherapy, and chemotherapy. Despite the lack of established guidelines, early intervention, even in metastatic cases, may improve clinical outcomes. Surgical resection, whenever appropriate, is advocated, as it not only alleviates symptoms, but intra-operative histological sampling also aids in obtaining a definitive diagnosis.

Soft tissue sarcoma mimicking an arteriovenous malformation - A case report and review of literature

INTRODUCTION AND IMPORTANCE

Arteriovenous malformation (AVM) is a rare condition affecting less than 5/10,000 people, with high misdiagnosis due to its heterogeneity, inconsistent nomenclature, and diverse diagnostic criteria. Understanding its prevalence in this age group is crucial for effective treatment. Here we present a case report of a patient with AVM. IRB approval and patient consent were obtained. This study was done based on SCARE criteria.

CASE PRESENTATION

A 53-year-old female patient was diagnosed with a right hip vascular mass suggestive of AVM. The patient reported painless swelling on the right hip for five years, initially increasing in size but significantly increasing in the last six months. The patient had no history of trauma, neurological or pelvic symptoms, or constitutional symptoms. An examination of the lower limbs revealed a firm, non-tender mass measuring approximately 15 × 15 cm. A thigh MRI revealed a sizable, well-rounded, lobulated soft tissue mass with a stromal structure and pronounced vascularity, indicative of a soft tissue tumor.

CLINICAL DISCUSSION

AVMs misdiagnosis is a significant issue, with 40 % of soft tissue sarcomas still misdiagnosed delaying care and leading to unnecessary measures. A 2015 study found 42.5 % of AMV patients were misdiagnosed, and 71 % were misdiagnosed as hemangiomas. Management involves multidisciplinary approaches, including radiology, sclerotherapy, surgical resection, and chemo/radiotherapy. Sirolimus may improve AVM prognosis.

CONCLUSION

Misdiagnosis of AVMs is a significant issue, with 40 % of soft tissue sarcomas still misdiagnosed. Management involves multidisciplinary approaches, including interventional radiology, sclerotherapy, surgical resection, and chemo/radiotherapy.

Soft Tissue Vascular Anomalies of the Extremities: A Proposed Diagnostic Approach

This narrative review aims to summarise the classification of vascular anomalies, their clinical presentation, and their radiological features to propose a diagnostic algorithm to approach patients with suspected soft tissue vascular anomalies of the extremities. The management of vascular anomalies necessitates a multidisciplinary approach. Clinical presentation and physical examination are sufficient in most cases to achieve a correct diagnosis. This is especially true for small congenital lesions of the skin and subcutaneous tissue. Imaging is used for accurate characterization of these lesions, especially in cases of atypical or vague clinical presentation, and to assess extension in cases of lesions that are larger and localized in deeper tissues.

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.

Noninvoluting congenital hemangiomas with hypovolemic shock, anemia and prolonged jaundice in a neonate: a case report

Noninvoluting congenital hemangioma is an extremely rare congenital anomaly in newborn babies and may complicate life-threatening events, including hemorrhage. We present a very rare case of noninvoluting congenital hemangiomas in an Asian and Afghan six-day-old girl that was detected at birth. The noninvoluting congenital hemangiomas were accompanied by hypovolemic shock, anemia, and prolonged jaundice during the first two weeks of life. These diseases were diagnosed by medical history, physical examination, blood analysis, and doppler ultrasonography of the skin lesions. Her hypovolemic shock and hemorrhage were improved after supportive treatment, and she was discharged from the hospital in a good condition. After four weeks of life, the hemangiomas did not regress or progress, suggesting noninvoluting congenital hemangiomas. Hemangioma may complicate severe hemorrhage and shock, as well as there may be an association between congenital hemangioma and prolonged neonatal jaundice.

Effects of follicle-stimulating hormone on the proliferation and apoptosis of infantile hemangioma stem cells

Objective

To investigate the effects of different concentrations of follicle-stimulating hormone (FSH) on the proliferation and apoptosis of human hemangioma stem cells, it will provide a basis for studying the mechanism of FSH in treating hemangioma.

Methods

Hemangioma specimens were collected from the Longgang District Maternity & Child Healthcare Hospital of Shenzhen City. Hemangioma stem cells were treated with different concentrations of FSH. Cell viability was detected by CCK8 method and cell apoptosis was analyzed by flow cytometry.

Results

Hemangioma stem cells (HemSCs) were extracted from fresh tissue of infantile hemangioma by the CD133 immunomagnetic bead method. Under the influence of FSH at different concentrations (0, 100, 1000 IU/L), the cell viability of hemangioma stem cells increased significantly in a concentration-dependent manner (P < 0.05). At the same time, the apoptosis of hemangioma stem cells decreased with increasing concentrations of follicle-stimulating hormone (P < 0.05). Specifically, 1000 IU/L FSH significantly promoted the proliferation of hemangioma stem cells and inhibited their apoptosis.

Conclusion

High concentration of follicle-stimulating hormone can maintain the growth of hemangioma by promoting the proliferation and inhibiting the apoptosis of hemangioma stem cells.

Kaposiform hemangioendothelioma of the thigh: A case report

Kaposiform hemangioendothelioma is a rare, locally aggressive or borderline vascular tumor that typically affects infants. It presents as a purpuric cutaneous lesion and may be associated with life-threatening coagulation disorders, such as the Kasabach-Merritt phenomenon. The differential diagnosis can be challenging based on clinical presentation alone. Imaging plays a crucial role in the diagnostic workup, particularly magnetic resonance imaging. We present a case report of a 4-month-old patient with an enlarging vinous cutaneous mass on the thigh and coagulation abnormalities. Magnetic resonance imaging revealed a large, infiltrative, soft-tissue lesion with poorly defined margins and heterogeneous enhancement, that involved all muscle compartments of the thigh and was associated with lymphedema, stranding of the subcutaneous fat and cutaneous thickening. These findings were consistent with kaposiform hemangioendothelioma of the thigh and the diagnosis was confirmed by histopathological characterization.

Vascular Malformations and Tumors: A Review of Classification and Imaging Features for Cardiothoracic Radiologists

The International Society for the Study of Vascular Anomalies (ISSVA) classification is a comprehensive histology-based scheme that was updated in 2018. It is important for cardiothoracic imagers to understand this classification to ensure that accurate terminology is used and that archaic terms are avoided when vascular lesions are described. Knowledge of the various malformations (including common conditions, such as venous malformation, arteriovenous fistula, and arteriovenous malformation) and vascular tumors allows for timely diagnosis and appropriate management. This review describes various vascular anomalies, in accordance with ISSVA classification and terminology; highlights key imaging features associated with each; and discusses the role of different imaging modalities. Keywords: Pulmonary, Soft Tissues/Skin, Vascular, Arteriovenous Malformation © RSNA, 2023.

Current concepts of vascular anomalies

Vascular anomalies encompass a variety of malformations and tumors that can result in severe morbidity and mortality in both adults and children. Advances have been made in the classification and diagnosis of these anomalies, with the International Society for the Study of Vascular Anomalies establishing a widely recognized classification system. In recent years, notable progress has been made in genetic testing and imaging techniques, enhancing our ability to diagnose these conditions. The increasing sophistication of genetic testing has facilitated the identification of specific genetic mutations that help treatment decisions. Furthermore, imaging techniques such as magnetic resonance imaging and computed tomography have greatly improved our capacity to visualize and detect vascular abnormalities, enabling more accurate diagnoses. When considering reconstructive surgery for facial vascular anomalies, it is important to consider both functional and cosmetic results of the procedure. Therefore, a comprehensive multidisciplinary approach involving specialists from dermatology, radiology, and genetics is often required to ensure effective management of these conditions. Overall, the treatment approach for facial vascular anomalies depends on the type, size, location, and severity of the anomaly. A thorough evaluation by a team of specialists can determine the most appropriate and effective treatment plan.

Vascular anomalies: diagnostic features and step-wise approach

The first part of this review article emphasized correct nomenclature, classification systems, and imaging algorithm of vascular anomalies. The second part of the review discusses the individual entities, highlighting the characteristic clinico-radiological features of the commonly encountered ones. A step-wise algorithmic approach is also proposed for the evaluation of a suspected case of vascular anomaly.

Reference values for paediatric abdominal aorta on B-mode ultrasound - an outer-to-outer methodology

BACKGROUND

B-mode ultrasound is versatile and safe. The sequelae of aortic disorders in children range from stunted growth in hypoplasia to 90% fatality in ruptured aneurysms. Thus, age-based reference values are necessary for early detection of abnormal aortic dimensions.

OBJECTIVE

To create age-based reference values of paediatric aorta diameters from B-mode ultrasound using the outer-to-outer method.

MATERIALS AND METHODS

A retrospective review was done of records of peak systolic anteroposterior aortic diameters, obtained during abdominal ultrasound in children ages 2 days to 17 years between January 2016 and December 2019. Cases were grouped into five age groups.

RESULTS

A total of 643 cases (49% female) were recruited into the study. Only 488 cases (76%) had values for the proximal, mid and distal aorta. The cumulative mean age was 9.5±5.1 years while the mean aortic diameter ranged from 0.3 cm to 1.8 cm. Tables of aortic diameters and reference ranges are presented. There was no significant sex difference. Significant positive correlation was only seen between age and aortic diameters (Pearson's r ranges from 0.66 to 0.91).

CONCLUSION

An age-based paediatric aortic reference table from B-mode ultrasound using outer-to-outer measurement in a Nigerian population is reported.

A Cosmetic Approach to Cheek and Nasal Hemangioma Utilizing Open Rhinoplasty in a 10-Year-Old Child: A Case Report

Infantile hemangiomas are characterized as benign tumors of vascular tissue that arise from rapid endothelial cell proliferation followed by gradual involution, affecting 4% to 5% in infants and 2.6% to 9.9% in older children. Most of them resolve by the age of three years, negating the need for surgical intervention. However, intervention should be considered especially in cases with a high risk of recurrence. A female patient, aged 10 years, was referred to plastic surgery by her dermatologist due to the presence of a vascular mass in her face located at the junction between the nose and right cheek that had been present since infancy. The patient was diagnosed with infantile hemangioma based on MRI imaging of the face showing a benign vascular lesion measuring 9 x 12 mm. After the failure of multiple sclerotherapy sessions and informed discussion with the respective family, the patient underwent open rhinoplasty for surgical excision with no facial scarring other than the transcellular scar. This study presents a rare case of utilizing the open rhinoplasty technique in a relapsing facial hemangioma of a 10-year-old child. Results show a positive aesthetic outcome by minimizing facial scars. Considering the limited reported use of this technique, more clinical studies, especially comparing long-term effects across different age populations, are recommended to validate the efficiency and effectiveness of this technique.

Stepwise approach for vertebral hemangioma in children: case-reports and treatment algorithm proposal

PURPOSE

To discuss a treatment algorithm for vertebral hemangioma in children.

METHODS

Vertebral hemangioma (VH) is a rare cause of low back pain in children. In most cases, VHs present as incidental findings and do not require invasive diagnostic procedure. In case of symptomatic presentation, different approaches can be used. Over the years, we have developed a treatment algorithm for VH in children based on our clinical experience. In this manuscript, we propose a stepwise approach to treatment of VHs based on tumor extension and the degree of spinal cord/nerves compression with or without neurological deficit.

RESULTS

According to the proposed protocol, we discuss two cases of aggressive VH treated at our institution by a multidisciplinary team. The first case is about a young girl treated with percutaneous one-level posterior instrumentation followed by medical adjuvant therapy for an L4 "Stage 3" VH. The second case is about an 8-year-old boy with rapidly progressive myelopathy due to T11 "Stage 4" VH treated with a combined anterior and posterior surgery (i.e., posterior decompression and fusion followed by vertebrectomy and expandable cage placement) after preoperative arterial embolization.

CONCLUSION

Given the lack of international guidelines and consensus with regard to treatment of VHs in children, we believe our proposal for a stepwise approach combining clinical and radiological characteristics of the lesion may help guide treatment of this condition in children.

The role of liver transplantation in the care of primary hepatic vascular tumours in children

Liver transplantation (LT) is the standard of care for many liver conditions, such as end-stage liver diseases, inherited metabolic disorders, and primary liver malignancies. In the latter group, indications of LT for hepatoblastoma and hepatocellular carcinoma evolved and are currently available for many non-resectable cases. However, selection criteria apply, as the absence of active metastases. Evidence of good long-term outcomes has validated the LT approach for managing these malignancies in the context of specialist and multidisciplinary approach. Nevertheless, LT's role in treating primary vascular tumours of the liver in children, both benign and malignant, remains somewhat controversial. The rarity of the different diseases and the heterogeneity of pathological definitions contribute to the controversy and make evaluating the benefit/risk ratio and outcomes quite difficult. In this narrative review, we give an overview of primary vascular tumours of the liver in children, the possible indications and the outcomes of LT.

Identifying erroneously used terms for vascular anomalies: A review of the English literature

Background

The classification of vascular anomalies includes terms of nomenclature that are not based on histogenesis resulting in confusion among health professionals of different specialties. Ongoing efforts to classify them properly have taken place. This literature review aimed to identify erroneous nomenclature of vascular anomalies and to investigate their continued use over the past four years after the last International Society for the Study of Vascular Anomalies (ISSVA) update.

Methods

Literature research was based on pertinent classifications (ISSVA, WHO) and books related to vascular anomalies and soft tissue pathology. After identifying twelve entities with confusing terminology, new research in the Pubmed database was conducted to verify their continued use in the last four years.

Results

The literature review highlighted terms referring to vascular malformations as neoplasms. In addition, terms used as equivalents represent entirely different entities. On the other hand, different terms to characterize the same entity were also recorded. Furthermore, regardless of the last ISSVA update in 2018, terms that are only descriptive or do not correspond to vascular anomaly histogenesis are consistently used.

Conclusion

Despite intensive efforts in the last decades for correct terminology and classification of vascular anomalies, modifications are still required. A common and broadly accepted scientific terminology should be applied, accurately representing histogenesis or pathogenesis, to obtain a common language among medical specialists, given that a multidisciplinary approach is crucial for managing vascular anomalies. HIPPOKRATIA 2022, 26 (4):126-130.

VEGF Pathway Gene Expression Profile of Proliferating versus Involuting Infantile Hemangiomas: Preliminary Evidence and Review of the Literature

Background. Infantile hemangiomas may have unexpected behavior. Initial regression (spontaneously or drug-induced) may be followed by unexplained recurrences. At this moment, there are no well-established criteria to predict infantile hemangioma reccurrences. Methods. We compared the VEGF pathway gene expression profile for one case of involuting infantile hemangioma versus one case of recurrent proliferative infantile hemangioma using TaqMan Array. Results. We found ten genes upregulated for both involuting and recurrent proliferative hemangiomas: ACTB, KRAS, MAP2K1, HRAS, NOS3, BAD, HSPB1, HPRT1, GUSB, and CASP9. Thirteen genes were downregulated for both involuting and proliferative hemangiomas: FIGF, ACTG1, GRB2, MAPKAPK2, ACTG2, MAP2K2, MAPK3, HSP90AA1, MAP2K6, NRAS, ACTA1, KDR, and MAPK1. Three genes showed divergent expression between proliferating and involuting hemangiomas. Proliferating hemangioma had MAPK14 and AKT1 gene upregulation and ACTA2 downregulation. Involuting infantile hemangioma was characterized by ACTA2 upregulation and AKT1 and MAPK14 downregulation. Conclusions. Three genes, AKT1, p38/MAPK14, and ACTA2, were found to have divergent expression in proliferating and involuting infantile hemangiomas. Excepting AKT1, which was mentioned in the last ISSVA classification (strictly related to Proteus Syndrome), none of the other genes were reported. An accurate gene expression profile mapping of infantile hemangiomas together with a gene expression-based hemangioma classification is stringently needed.

Emerging Polymer Materials in Trackable Endovascular Embolization and Cell Delivery: From Hype to Hope

Minimally invasive endovascular embolization is a widely used clinical technique used for the occlusion of blood vessels to treat various diseases. Different occlusive agents ranging from gelatin foam to synthetic polymers such as poly(vinyl alcohol) (PVA) have been commercially used for embolization. However, these agents have some drawbacks, such as undesired toxicity and unintended and uncontrolled occlusion. To overcome these issues, several polymer-based embolic systems are under investigation including biocompatible and biodegradable microspheres, gelling liquid embolic with controlled occlusive features, and trackable microspheres with enhanced safety profiles. This review aims to summarize recent advances in current and emerging polymeric materials as embolization agents with varying material architectures. Furthermore, this review also explores the potential of combining injectable embolic agents and cell therapy to achieve more effective embolization with the promise of outstanding results in treating various devastating diseases. Finally, limitations and challenges in developing next-generation multifunctional embolic agents are discussed to promote advancement in this emerging field.

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.

Interventional Treatment Options in Children with Extracranial Vascular Malformations

Extracranial vascular malformations vary greatly and belong to the complex field of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic system. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) represents an important guidance for selecting appropriate therapy. Although many of the principles of endovascular treatment, including image-guided sclerotherapy and embolization, are similar in adult and pediatric practice, there are some distinct differences regarding the treatment of vascular malformations of children. Thus, it is crucial to involve longer-term plan about managing these chronic diseases and their impact on a growing child. This review provides a detailed overview over the clinical presentation of venous, lymphatic, and arteriovenous malformations in children and emphasizes the specifics of their interventional treatment options, including distinct pediatric dose limitations and procedure-related side effects.

Vascular lesions of the pediatric orbit: A radiological walkthrough

Vascular anomalies of the pediatric orbit represent a heterogeneous group that include both vascular tumors and vascular malformations. The disorder may initially be silent and then associated with symptoms and/or function damage, depending on the type of vascular anomaly and its extension. Vascular tumors include benign, locally aggressive (or borderline) and malignant forms while vascular malformations are divided into "simple", "combined" and syndromic, or "low flow" or "high flow". Both entities can arise in isolation or as part of syndromes. In this review, we describe the imaging findings of the vascular lesions of the orbit in the pediatric population, which are key to obtain a correct diagnosis and to guide the appropriate treatment in the light of the new genetic and molecular discoveries, and the role of the radiologist in their multidisciplinary management. We will also touch upon the main syndromes associated with orbital vascular abnormalities.

What do Cochrane systematic reviews say about congenital vascular anomalies and hemangiomas? A narrative review

BACKGROUND

Congenital vascular anomalies and hemangiomas (CVAH) such as infantile hemangiomas, port-wine stains and brain arteriovenous malformations (AVMs) impair patients' lives and may require treatment if complications occur. However, a great variety of treatments for those conditions exist and the best interventions remain under discussion.

OBJECTIVE

To summarize Cochrane systematic review (SR) evidence on treatments for CVAH.

DESIGN AND SETTING

Review of SRs conducted in the Division of Vascular and Endovascular Surgery of Universidade Federal de São Paulo, Brazil.

METHODS

A broad search was conducted on March 9, 2021, in the Cochrane Database of Systematic Reviews to retrieve any Cochrane SRs that assessed treatments for CVAH. The key characteristics and results of all SRs included were summarized and discussed.

RESULTS

A total of three SRs fulfilled the inclusion criteria and were presented as a qualitative synthesis. One SR reported a significant clinical reduction of skin redness by at least 20%, with more pain, among 103 participants with port-wine stains. One SR reported that propranolol improved the likelihood of clearance 13 to 16-fold among 312 children with hemangiomas. One SR reported that the relative risk of death or dependence was 2.53 times greater in the intervention arm than with conservative management, among 218 participants with brain AVMs.

CONCLUSION

Cochrane reviews suggest that treatment of port-wine stains with pulsed-dye laser improves redness; propranolol remains the best option for infantile hemangiomas; and conservative management seems to be superior to surgical intervention for treating brain AVMs.

Imaging of peripheral vascular malformations - current concepts and future perspectives

Vascular Malformations belong to the spectrum of orphan diseases and can involve all segments of the vascular tree: arteries, capillaries, and veins, and similarly the lymphatic vasculature. The classification according to the International Society for the Study of Vascular Anomalies (ISSVA) is of major importance to guide proper treatment. Imaging plays a crucial role to classify vascular malformations according to their dominant vessel type, anatomical extension, and flow pattern. Several imaging concepts including color-coded Duplex ultrasound/contrast-enhanced ultrasound (CDUS/CEUS), 4D computed tomography angiography (CTA), magnetic resonance imaging (MRI) including dynamic contrast-enhanced MR-angiography (DCE-MRA), and conventional arterial and venous angiography are established in the current clinical routine. Besides the very heterogenous phenotypes of vascular malformations, molecular and genetic profiling has recently offered an advanced understanding of the pathogenesis and progression of these lesions. As distinct molecular subtypes may be suitable for targeted therapies, capturing certain patterns by means of molecular imaging could enhance non-invasive diagnostics of vascular malformations. This review provides an overview of subtype-specific imaging and established imaging modalities, as well as future perspectives of novel functional and molecular imaging approaches. We highlight recent pioneering imaging studies including thermography, positron emission tomography (PET), and multispectral optoacoustic tomography (MSOT), which have successfully targeted specific biomarkers of vascular malformations.

Update on infantile hemangioma

The International Society for the Study of Vascular Anomalies classifies vascular anomalies into vascular tumors and vascular malformations. Vascular tumors are neoplasms of endothelial cells, among which infantile hemangiomas (IHs) are the most common, occurring in 5%-10% of infants. Glucose transporter-1 protein expression in IHs differs from that of other vascular tumors or vascular malformations. IHs are not present at birth but are usually diagnosed at 1 week to 1 month of age, rapidly proliferate between 1 and 3 months of age, mostly complete proliferation by 5 months of age, and then slowly involute to the adipose or fibrous tissue. Approximately 10% of IH cases require early treatment. The 2019 American Academy of Pediatrics clinical practice guideline for the management of IHs recommends that primary care clinicians frequently monitor infants with IHs, educate the parents about the clinical course, and refer infants with high-risk IH to IH specialists ideally at 1 month of age. High-risk IHs include those with life-threatening complications, functional impairment, ulceration, associated structural anomalies, or disfigurement. In Korea, IHs are usually treated by pediatric hematology-oncologists with the cooperation of pediatric cardiologists, radiologists, dermatologists, and plastic surgeons. Oral propranolol, a nonselective beta-adrenergic antagonist, is the first-line treatment for IHs at a dosage of 2-3 mg/kg/day divided into 2 daily doses maintained for at least 6 months and often continuing until 12 months of age. Topical timolol maleate solution, a topical nonselective beta-blocker, may be used for small superficial type IHs at a dosage of 1-2 drops of 0.5% gel-forming ophthalmic solution applied twice daily. Pulse-dye laser therapy or surgery is useful for the treatment of residual skin changes after IH involution.

Case Report: A Primary Right Ventricular Vascular Malformation Presenting as a Mass

Primary right ventricular vascular malformation is a rare primary benign anomaly in heart in nature. Due to the extremely low incidence and the progress on the classification of vascular malformation, a few cases were reported in the literatures. In the current case study, a 55-year-old women presented with a cardiac mass that was identified in right ventricle during a routine medical checkup. Magnetic resonance imaging demonstrated a well-circumscribed mass attached to the interventricular septum. Median sternotomy for the surgical resection of the mass and a cardiopulmonary bypass were performed. The intraoperative transesophageal echocardiogram showed that the mass had been successfully removed. The patient recovered well and was discharged from hospital 9 days after the surgery. The pathological diagnosis was primary cardiac arteriovenous malformation. No mass recurrence was shown by echocardiography during the 13 months' follow-up.

Propranolol in the Treatment of Infantile Hemangiomas

Propranolol, as the first generation of β-blocker family, was initially introduced in the clinical application for tachycardia and hypertension in the 1960s. However, the occasional discovery of propranolol in the involution of infantile hemangiomas (IHs) brought us a new perspective. IHs are the most common infantile tumor, affecting 4–10% newborns. So far, oral propranolol is the first-line medication for IHs treatment. At the same time, local injection and topical propranolol are developing. Despite the worldwide application, the precise mechanism of propranolol of IHs has not been completely studied. In this article, we reviewed and summarized the current information on pharmacology, mechanism, efficacy, and adverse effects of propranolol. Novel design of biomaterials and bioactive molecules are needed for new treatment and ideal pathway to attain the minimal effective treatment concentration and eliminate the adverse effects.

Imaging of benign cervicofacial vascular anomalies and associated syndromes

Cervicofacial vascular anomalies can result in morbidity, pain, and cosmetic concerns in affected individuals. Each anomaly has its own unique natural history, treatment, and associations with underlying genetic syndromes. For optimal patient care, it is important for the neuroradiologist to accurately recognize and characterize these entities to ensure appropriate treatment and management. In this review, we discuss the general characteristics, classifications, and imaging features associated with the most common vascular anomalies such as hemangiomas, arteriovenous malformations and fistulas, capillary malformations, venous malformations, and lymphatic malformations in the context of associated syndromes. Additionally, we discuss novel imaging techniques that aid in identifying these vascular anomalies.

Mediastinal Masses in Children: Radiologic-Pathologic Correlation

Most pediatric masses in the chest are located in the mediastinum. These masses are often initially detected incidentally on chest radiographs in asymptomatic children, although some patients may present with respiratory symptoms. At chest radiography, the mediastinum has been anatomically divided into anterior, middle, and posterior compartments. However, with the International Thymic Malignancy Interest Group classification scheme, which is based on cross-sectional imaging findings, the mediastinum is divided into prevascular, visceral, and paravertebral compartments. In the prevascular compartment, tumors of thymic origin, lymphomas, germ cell tumors, and vascular tumors are encountered. In the visceral compartment, lymphadenopathy and masses related to the foregut are seen. In the paravertebral compartment, neurogenic tumors are most common. Using the anatomic location in combination with knowledge of the imaging and pathologic features of pediatric mediastinal masses aids in accurate diagnosis of these masses to guide treatment and management decisions. An invited commentary by Lee and Winant is available online. ^©RSNA, 2021.

The effectiveness of oral propranolol for infantile hemangioma on the head and neck region: A case series

Introduction

Infantile hemangioma is the most common tumor in infancy, with 60% occurring on the face and neck. A large tumor involving the facial region will cause significant aesthetic and functional impairment and isn't always easy to treat surgically. A non-invasive treatment is needed for this condition. Propranolol has recently been used as a choice of treatment in infantile hemangioma.

Presentation of case

We presented two cases of large problematic infantile hemangioma that were successfully managed with oral propranolol.

Discussion

Large problematic lesions that ulcerate and bleed often need surgery; however, a substantial defect resulting from surgery is tricky to reconstruct and can cause significant scar. Propranolol is used because of its efficacy and low risk characteristics.

Conclusion

Propranolol is an effective treatment to reduce the need of surgical intervention in problematic hemangioma.

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Hemangioma is the most common tumor in infancy, grows rapidly, slowly regress, and never recur

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Not all hemangioma with ulceration and bleeding are good candidates for surgery due to the large defect it may produce

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Propanolol is an effective alternative treatment before surgery in problematic hemangioma, especially if given during proliferative phase

Versatile Vessel-on-a-Chip Platform for Studying Key Features of Blood Vascular Tumors

Tumor vessel-on-a-chip systems have attracted the interest of the cancer research community due to their ability to accurately recapitulate the multiple dynamic events of the metastatic cascade. Vessel-on-a-chip microfluidic platforms have been less utilized for investigating the distinctive features and functional heterogeneities of tumor-derived vascular networks. In particular, vascular tumors are characterized by the massive formation of thrombi and severe bleeding, a rare and life-threatening situation for which there are yet no clear therapeutic guidelines. This is mainly due to the lack of technological platforms capable of reproducing these characteristic traits of the pathology in a simple and well-controlled manner. Herein, we report the fabrication of a versatile tumor vessel-on-a-chip platform to reproduce, investigate, and characterize the massive formation of thrombi and hemorrhage on-chip in a fast and easy manner. Despite its simplicity, this method offers multiple advantages to recapitulate the pathophysiological events of vascular tumors, and therefore, may find useful applications in the field of vascular-related diseases, while at the same time being an alternative to more complex approaches.

Rare Diseases of the Orbit

This article provides an overview of rare orbital diseases. Congenital malformations, inflammatory diseases, benign and malignant neoplasias are described. Although it represents a relatively small area of the body the orbit contains multiple different tissues. Therefore, a great variety of diseases can be found within the orbital space. That is the reason, why both the completeness and the level of detail in the description of particular diseases must be somewhat limited. Nevertheless, clinical manifestations, important aspects of diagnosis, treatment strategies, and, when specific data are available, the prognosis are described. The authors tried to highlight the most characteristic aspects of the different diseases to describe their relevant aspects in spite of the brevity of the subsections.

Postcricoid haemangioma with laryngomalacia in infancy

Infantile haemangioma represents a congenital vascular anomaly commonly observed in the head and neck region. Such an occurrence over the postcricoid region, however, is rather unusual. Herein, the authors report a case of a synchronous postcricoid haemangioma in a 7-week-old newborn diagnosed with severe laryngomalacia. In addition to the floppy redundant arytenoid mucosa, flexible laryngoscopy revealed a lobulated bluish mass at the postcricoid. The lesion was hyperintense on T1-weighted sequence and was enhanced with contrast, supporting the diagnosis of a haemangioma. She underwent surgical excision of the haemangioma with intralesional steroid injection. Surveillance at 6-month postoperation did not show disease recurrence.

Management of vascular malformations in the Oral and maxillofacial region: A systematic review

OBJECTIVE

The purpose is to determine the comprehensive review and the current concepts on the management of vascular malformation and to evaluate the long term outcomes, recurrence and complication rate.

METHODS

This systematic review followed PRISMA guidelines and registered in PROSPERO (CRD42020173735). The PUBMED, EBSCO, SCOPUS and NDH databases were used to perform a comprehensive search of articles published up until July 2020. The database search identified 1719 articles. After an intricate review, 34 studies were estimated for eligibility.

RESULTS

A total of 1719 patients with mean age of 27.48 years were treated for vascular malformation in the oral and maxillofacial region. Moderate heterogeneity was observed for the outcome (P = 0.166; 95% CI:1.01-1.46, I² = 48%). As determined by one-way ANOVA, there was no statistically significant difference between the type of diagnosis and the recurrence (F = 2.313, p = 0.092) and the complication rate (F = 2.112, p = 0.117).

CONCLUSION

In accordance with the available scientific literature, this review has highlighted the modalities and advancement in the management of vascular malformations. Complications and recurrence were reported in all types of management. It can be avoided by careful diagnosis, pre-operative assessment and treatment planning.

Infantile Hemangioma: An Updated Review

BACKGROUND

Infantile hemangiomas are the most common vascular tumors of infancy, affecting up to 12% of infants by the first year of life.

OBJECTIVE

To familiarize physicians with the natural history, clinical manifestations, diagnosis, and management of infantile hemangiomas.

METHODS

A Pubmed search was conducted in November 2019 in Clinical Queries using the key term "infantile hemangioma". The search strategy included meta-analyses, randomized controlled trials, clinical trials, observational studies, and reviews published within the past 20 years. Only papers published in the English literature were included in this review. The information retrieved from the above search was used in the compilation of the present article.

RESULTS

The majority of infantile hemangiomas are not present at birth. They often appear in the first few weeks of life as areas of pallor, followed by telangiectatic or faint red patches. Then, they grow rapidly in the first 3 to 6 months of life. Superficial lesions are bright red, protuberant, bosselated, or with a smooth surface, and sharply demarcated. Deep lesions are bluish and dome-shaped. Infantile hemangiomas continue to grow until 9 to 12 months of age, at which time the growth rate slows down to parallel the growth of the child. Involution typically begins by the time the child is a year old. Approximately 50% of infantile hemangiomas will show complete involution by the time a child reaches age 5; 70% will have disappeared by age 7; and 95% will have regressed by 10 to 12 years of age. The majority of infantile hemangiomas require no treatment. Treatment options include oral propranolol, topical timolol, and oral corticosteroids. Indications for active intervention include hemorrhage unresponsive to treatment, impending ulceration in areas where serious complications might ensue, interference with vital structures, life- or function-threatening complications, and significant disfigurement.

CONCLUSION

Treatment should be individualized, depending upon the size, rate of growth, morphology, number, and location of the lesion (s), existing or potential complications, benefits and adverse events associated with the treatment, age of the patient, level of parental concern, and the physician's comfort level with the various treatment options. Currently, oral propranolol is the treatment of choice for high-risk and complicated infantile hemangiomas. Topical timolol may be considered for superficial infantile hemangiomas that need to be treated and for complicated infantile hemangiomas in patients at risk for severe adverse events from oral administration of propranolol.

Additive value of transarterial embolization to systemic sirolimus treatment in kaposiform hemangioendothelioma

Kaposiform hemangioendothelioma (KHE) is a rare vascular tumor in children, which can be accompanied by life-threatening thrombocytopenia, referred to as Kasabach-Merritt phenomenon (KMP). The mTOR inhibitor sirolimus is emerging as targeted therapy in KHE. As the sirolimus effect on KHE occurs only after several weeks, we aimed to evaluate whether additional transarterial embolization is of benefit for children with KHE and KMP. Seventeen patients with KHE and KMP acquired from 11 hospitals in Germany were retrospectively divided into two cohorts. Children being treated with adjunct transarterial embolization and systemic sirolimus, and those being treated with sirolimus without additional embolization. Bleeding grade as defined by WHO was determined for all patients. Response of the primary tumor at 6 and 12 months assessed by magnetic resonance imaging (MRI), time to response of KMP defined as thrombocyte increase >150 × 10³ /μL, as well as rebound rates of both after cessation of sirolimus were compared. N = 8 patients had undergone additive embolization to systemic sirolimus therapy, sirolimus in this group was started after a mean of 6.5 ± 3 days following embolization. N = 9 patients were identified who had received sirolimus without additional embolization. Adjunct embolization induced a more rapid resolution of KMP within a median of 7 days vs 3 months; however, tumor response as well as rebound rates were similar between both groups. Additive embolization may be of value for a more rapid rescue of consumptive coagulopathy in children with KHE and KMP compared to systemic sirolimus only.

Case of epithelioid hemangioendothelioma occurring in the postradiation setting for breast cancer

Epithelioid hemangioendothelioma (EHE) is a rare malignant vascular tumor, which is typically characterized by recurrent fusion genes. EHEs most commonly occur in the lung, liver, bone, and internal organs. EHE has rarely been reported to occur in the post-radiotherapeutic setting, the breast site or in association with breast cancer. The differential diagnosis for radiation-associated vascular lesions of the breast is classically limited to atypical vascular lesion and angiosarcoma and does not include EHE. We present the case of a woman with a history of breast cancer and post-surgical radiotherapy who went on to develop an EHE of the chest wall skin within 3 years of the completion of radiotherapy. Microscopically, the lesion was infiltrative and composed of anastomosing nests of epithelioid-to-spindled cells with eosinophilic and vacuolated cytoplasm. By immunohistochemistry, the cells were positive for ERG, D2-40, and CD31. The diagnosis was confirmed by identification of a characteristic WWTR1-CAMTA1 fusion gene using RNA sequencing. This case expands our understanding of radiation-associated tumors.

Efficacy of Combined Topical Timolol and Oral Propranolol for Treating Infantile Hemangioma: A Meta-Analysis of Randomized Controlled Trials

Background

Oral propranolol has become the first-line treatment for infantile hemangioma (IH). However, combined therapy with topical timolol and oral propranolol has been proposed as a more effective IH treatment strategy. We aimed to compare the safety and efficacy of topical timolol, oral propranolol, and their combination for treating IH in a meta-analysis.

Methods

Relevant randomized controlled trials (RCTs) were obtained after searching the PubMed, Embase, Cochrane’s Library, China National Knowledge Infrastructure, and WanFang databases. A random-effect model was used to pool the results.

Results

Eight RCTs with 759 patients with IH were included in this meta-analysis. Treatment with topical timolol alone showed a similar response rate compared to oral propranolol (risk ratio [RR] = 0.97, p = 0.63), but resulted in fewer adverse events (RR = 0.36, p = 0.002). Combined treatment with topical timolol and oral propranolol showed a favorable response rate compared to treatment with oral propranolol (RR = 1.14, p = 0.03) or topical timolol (RR = 1.36, p = 0.01) alone. Moreover, combined treatment showed similar risks of adverse events compared to oral propranolol (RR = 0.80, p = 0.24) or topical timolol (RR = 1.31, p = 0.25) alone.

Conclusions

Combined treatment with topical timolol and oral propranolol may be more effective than either single treatment strategy in patients with IH. Topical timolol alone conferred similar efficacy for IH compared to oral propranolol, but with less incidence of adverse events.

Multifocal infantile hemangiomas associated with concomitant giant hepatic rapidly involuting congenital hemangioma

We present a 9-day-old girl with multifocal cutaneous and hepatic infantile hemangiomas as well as a hepatic rapidly involuting congenital hemangioma. These two distinct vascular tumors have rarely been reported to co-occur. We additionally review the sonographic features that distinguish a hepatic congenital hemangioma from the hepatic infantile hemangioma.

Giant Mesenteric Mixed Hemangioma Misdiagnosed as Ovarian Cyst: A Case Report and a Literature Review

Hemangiomas are congenital vascular disorders that occur primarily in the face and neck, extremely rare in the mesentery. Here, we report a rare small mesenteric mixed hemangioma. A 34-year-old woman was admitted to the gynecology department for an extended menstrual cycle. A cystic multi-atrial mass at the right anterior of uterus was observed by ultrasound examination, which was about 12.5 × 9.5 × 14.9 cm in size. The gynecologist mostly considered the possibility of the ovarian cyst. However, there was a huge multi-atrial cyst in the small intestine mesentery without the right ovarian cyst in the surgical exploration. The grape-like cystic mass about 15 cm in diameter adhered to the mesenteric root of the small intestine. The cyst was diagnosed as the mesenteric mixed hemangioma in the final histopathology.

Cystic extraskeletal osteosarcoma: Three case reports and review of the literature

Extraskeletal osteosarcoma is a rare soft tissue sarcoma and typically appears as a solid mass with variable mineralization. A few cases of extraskeletal osteosarcoma have shown extensive hemorrhagic changes or bleeding due to its high-grade malignancy; however, to the best of our knowledge, no previous reports have described the pathological characteristics of tumors with non-hemorrhagic cystic change. The present report discusses three cases involving cystic lesions with a solid area at the periphery that arose in soft tissues. The large cystic spaces contained only yellowish-brown fluid and little or no blood, with no clear pathological necrotic tissue. The solid component comprised a focal area of osteoid production by highly anaplastic sarcomatous cells. All of the cases showed high-grade malignancy histologically, and the average maximum diameter was approximately 175 mm. The tumors were located at the adductor muscles in two cases and at the intermuscular region of the hamstring muscles in one case. All of the patients consulted a doctor after more than half a year had passed since the recognition of swelling or a mass on their affected extremities. Surgical treatment was performed for all patients. One patient had lymph node metastasis, and another had lymphoedema after surgery, but no histological invasion to the lymphatic ducts was observed in the excised specimen. Degenerative changes in the fluid content over a long time-course as a result of tumor bleeding or necrosis, rather than lymphorrhea by lymphatic channel invasion of the tumor, might have contributed to the formation of the cystic lesion. Only 1 patient who underwent chemotherapy remained clinically disease-free over 10 years after surgery. Chemotherapy regimens for osteosarcoma rather than those for soft tissue sarcoma are mostly effective for extraskeletal osteosarcoma, so the diagnosis by a biopsy is essential. It is important to consider extraskeletal osteosarcoma in the differential diagnosis of soft tissue tumor with cystic form and calcification and a long clinical course before consulting a doctor.