Cutaneous vascular tumours: an update

Benign and low-grade superficial endothelial cell neoplasms in the molecular era

Vascular tumors are the most common mesenchymal neoplasms of the skin and subcutis, and they encompass a heterogeneous group with diverse clinical, histological, and molecular features, as well as biological behavior. Over the past two decades, molecular studies have enabled the identification of pathogenic recurrent genetic alterations that can be used as additional data points to support the correct classification of these lesions. The purpose of this review is to summarize the available data related to superficially located benign and low-grade vascular neoplasms and to highlight recent molecular advances with the role of surrogate immunohistochemistry to target pathogenic proteins as diagnostic biomarkers.

A Case Series of 18 Congenital Haemangiomas: Clinical, Histological and Ultrasound Features, and their Relationship with Complications and Atypical Behaviour

Recent studies have advanced our understanding of the clinical, histological and imaging characteristics of congenital haemangiomas (CHs), and have reported possible complications and atypical behaviour. The aim of this study is to describe the clinical, histological and ultrasound features of a series of CHs and to analyse their association with complications and atypical behaviour, with a view to providing diagnostic and management recommendations. The medical records, histology results and ultrasound images of all patients with CH diagnosed in the Dermatology Department of Alicante University General Hospital between 2006 and 2021 were retrospectively reviewed. A total of 18 patients were included, of whom 4 (22.2%) had complications. The most severe was 1 case with heart failure. There was a significant association between large CH size (> 5 cm) and the occurrence of complications (p = 0.019). The study identified 3 different lobule patterns, but found no relationship with CH subtype or other findings. The associations of venous ectasia, venous lakes and arteriovenous microshunts with occurrence of complications was borderline significant (p = 0.055). Study limitations were the small sample and the retrospective analysis. To conclude, haematological and cardiological assessment is indicated in large CHs and should be considered in CHs with ultrasound findings of venous ectasia, venous lakes or arteriovenous microshunts, as these cases present a greater risk of complications.

A unique case of multiple calvarial hemangiomas with one large symplastic hemangioma

BACKGROUND

Symplastic hemangioma is a benign superficial abnormal buildup of blood vessels, with morphological features which can mimic a pseudo malignancy. A few cases have been reported in the literature. We report here, a unique case of calvarial symplastic hemangioma, which is the first case in the calvarial region.

CASE PRESENTATION

A 29-year-old male patient, with a left occipital calvarial mass since childhood, that gradually increased in size with age, was associated with recurrent epileptic fits controlled by Levetiracetam (Keppra), with no history of trauma. He presented to the emergency room with a recent headache, vomiting, frequent epileptic fits and a decrease in the level of consciousness 1 day prior to admission. A CT scan showed three diploic, expansile, variable sized lytic lesions with a sunburst appearance; two that were biparietal, and one that was left occipital, which were all suggestive of calvarial hemangiomas. However, the large intracranial soft tissue content, within the hemorrhage of the occipital lesion was concerning. The patient had refused surgery over the years; however, after the last severe presentation, he finally agreed to treatment. The two adjacent, left parietal and occipital lesions were treated satisfactorily using preoperative embolization, surgical resection, and cranioplasty. Histopathology revealed cavernous hemangiomas, in addition to symplastic hemangioma (pseudo malignancy features) on top at the occipital lesion. The right parietal lesion was not within the surgical field; therefore, it was left untouched for follow-up.

CONCLUSIONS

Histopathology and radiology examinations confirmed the diagnosis as symplastic hemangioma, on top of a pre-existing cavernous hemangioma. To the best of our knowledge, this is the first case of a calvarial symplastic hemangioma, which we report here.

Symplastic hemangioma developing over an infantile hemangioma during propranolol treatment

We describe a case of a 6-month-old female patient with a segmental, superficial, infantile hemangioma (IH) on the forehead being treated with propranolol 2 mg/kg/d for 5 months, who developed a symplastic hemangioma (SH) over the preexisting lesion, highlighting the need to consider SH in the differential diagnosis of vascular lesions arising over preexisting vascular anomalies in children.

Cutaneous epithelioid angiomatous nodule: a report of a series including a case with moderate cytologic atypia and immunosuppression

BACKGROUND

Cutaneous epithelioid angiomatous nodule (CEAN) is a very rare and relatively recently recognized vascular proliferation characterized usually by minimal cytological atypia and accompanying mitotic activity. As such, CEAN represents an important diagnostic pitfall, which could lead to significant misdiagnosis and unnecessary treatment.

METHODS

The clinicopathologic findings of 5 cases of CEAN were reviewed including a unique case with typical findings but also moderate cytologic atypia and brisk mitotic activity in a patient on immunosuppression.

RESULTS

The cases were in 3 women and 2 men ranging in age from 18 to 61 years with lesions in the neck (2 cases), upper arm, back and shoulder. In 4 of the cases, the patients did not have any relevant potentially contributory clinical history, and in 1 case the patient was on immunosuppressive treatment. All 5 cases were superficially located within the dermis, well-circumscribed and similarly composed of epithelioid cells displaying minimal (in 4 cases) and moderate (1 case) atypia. The mitotic count ranged from 1 to 3 per 10 high power fields (HPF) in 4 cases and up to 9 per 10 HPF in the immunosuppressed patient. Atypical mitoses were not encountered in any of the cases. Two lesions that were incompletely excised recurred, but none of the patients showed distant metastases.

CONCLUSION

While cytologically alarming, CEAN has a characteristic microscopic appearance and if completely excised follows an indolent course.

Acquired Elastotic Hemangioma: Case Series and Comprehensive Literature Review

Background Acquired elastotic hemangioma is a benign vascular proliferation that typically presents as an asymptomatic red plaque on a sun-exposed site of an adult. Material and Methods The PubMed database was used to search the following words: acquired, angioma, arm, basal, carcinoma, cell, elastosis, elastotic, exposed, forearm, hemangioma, solar, sun, and vascular. The relevant papers and reference cited generated by the search were reviewed. The features from a case series of 11 patients with acquired elastotic hemangioma are presented. In addition, a comprehensive review of the characteristics of this unique hemangioma-not only in our 11 patients but also in the previously reported 34 individuals with this lesion-is provided. Results Acquired elastotic hemangioma, reported in 45 patients (24 women and 21 men), typically appeared as an asymptomatic solitary red plaque in sun-exposed areas-most commonly the forearm--of adults aged 50 years or older. The pathology shows a proliferation of vascular channels-surrounded and intertwined by intense solar elastosis--in the upper dermis, located parallel to the overlying epidermis, and separated from it by a zone of normal-appearing superficial papillary dermis. There was extensive solar elastosis surrounding and between the new blood vessels; some of the endothelial cells protrude (in a hob-nail pattern) into the vessel lumen. The clinical differential diagnosis includes basal cell carcinoma and the pathologic differential diagnosis includes other benign, malignant, and reactive vascular lesions. Ultraviolet radiation may contribute to the pathogenesis of this hemangioma since it occurs on sun-exposed sites. There was no recurrence of the lesion following either excision or observation. Conclusions The possibility of acquired elastotic hemangioma should be considered by clinicians when they encounter an older individual with a new red plaque on a sun-exposed site that clinically appears to be a superficial basal cell carcinoma.

Nasopharyngeal Capillary Arteriovenous Malformation with Ancient/Symplastic Change: A Simulator of Malignancy

There are only 8 published cases of symplastic hemangioma (SH), a relatively recently described, distinct benign entity characterized by pleomorphic vascular smooth muscle and interstitial cells in a pre-existing, long-standing vascular lesion. Seven of these cases were of SH in cutaneous locations, and 1 case was described in the mediastinum. We report the case of the 12-year-old girl with a nasopharyngeal tumor mass with prominent symplastic changes arising in the background of a combined capillary arteriovenous malformation. After critical analysis of all published cases of SH, it is clear that these lesions commonly represent capillary arteriovenous malformations (CAVM) with ancient/symplastic changes according to current terminology proposed in the classification required by the International Society for the Study of Vascular Anomalies (ISSVA). This is the first such lesion reported in a mucosal location and presenting in the pediatric age group. CAVM with ancient/symplastic change follows a benign clinical course, but it can simulate a malignant vascular tumor.

Use of X-Chromosome Inactivation Pattern to Analyze the Clonality of 14 Female Cases of Kaposi Sarcoma

Background

Kaposi sarcoma (KS) has features of both neoplastic growth and hyperplastic proliferation. It is the most common tumor seen in patients with HIV infection. Whether KS is a real tumor or a benign hyperplastic disease is not known.

Material/Methods

Tissues from KS and cutaneous hemangioma lesion DNA were extracted, and then digested with methylation-sensitive restriction endonuclease HpaII. Human androgen receptor gene (HUMARA) was amplified with PCR method and the product was separated on 10% denaturing polyacrylamide gels and stained with ethylene dibromide (EB) to show the polymorphism of HUMARA. Phosphoglycerate kinase (PGK) was amplified and the product was digested by BStXI, agarose gel and EB stained to show the polymorphism of PGK. Finally, we analyzed the clonality of KS.

Results

In the 14 patients with KS, heterozygosity of the HUMARA gene was observed in 12 (85.7%) cases. Loss of heterozygosity of HUMARA gene on X-chromosome (without HpaII digestion there were 2 bands, after HpaII digestion there were just 1 of the bands), representing monoclonal origin, was present in 11 cases of Kaposi sarcoma. Heterozygosity of the PGK gene was observed in 5 (35.7%) cases, which all represent monoclonal origin. There was no significant difference according to country, stage, or HIV and HHV-8 (P>0.05).

Conclusions

The current findings suggest that Kaposi sarcoma is a clonal neoplasm, not a reactive proliferation.

Epithelioid angiomatous nodule of the nasal cavity: Report of 2 cases

Epithelioid angiomatous nodule (EAN) is a novel clinicopathological entity characterized by a benign proliferation of endothelial cells with prominent epithelioid features. It can arise from any region of the body although it is increasingly being recognized in the head and neck. This paper presents two cases of EAN arising in the nasal cavity where the clinical presentations were recurrent unilateral epistaxis. In both cases, the lesions were excised endoscopically. Histopathologic analysis showed well-circumscribed proliferation of solid sheets of epithelioid endothelial cells and vascular channels in a background of mild chronic inflammatory infiltrate. Cytologic atypia was absent with rare mitotic figures seen. Immunohistochemical studies with CD31 and CD34 were strongly positive, thus confirming a vascular origin. Postoperative recovery was uneventful and no recurrence was seen in the follow-up period. EAN can be differentiated from other lesions demonstrating epithelioid vascular proliferation by means of clinical and histopathological characteristics. The present series seeks to inform that EAN should be regarded as a possible, albeit rare, cause of recurrent unilateral epistaxis. We advocate for endoscopic excision of EAN of the nasal cavity for diagnostic and therapeutic purposes.

Composite Hemangioendothelioma of the Submandibular Region

Composite hemangioendothelioma (HE) is a rare vascular neoplasm of intermediate malignant potential that predominantly occurs within the dermis or subcutis of the extremities, and occurs in a wide age range. It is locally aggressive with a high rate of local recurrence, and more rarely regional lymph node or distant metastasis. Histologically, it is composed of a complex admixture of benign, intermediate and malignant vascular components. Although composite HE may contain angiosarcoma-like areas, its prognosis is better than that of pure angiosarcoma. We describe a case of composite HE presenting as a submandibular mass in a 43 year-old male, which included areas of prominent 'high grade' epithelioid angiosarcoma. This adds to the range of anatomic sites of these neoplasms, highlights the importance of recognition of the head and neck as a potential site, and emphasizes the importance of accurate diagnosis for correct management (including of long term follow up) and prognostication.

Giant cell angioblastoma in an adult: a unique presentation

Giant cell angioblastoma is a very rare, locally destructive vascular tumor of intermediate malignancy without metastatic potential. There are only a few cases reported in the literature exclusively in the soft tissue of children. For the first time, we report on an adult patient with a giant cell angioblastoma in the popliteal fossa. The therapy included tumor resection with favorable clinical, oncological and functional outcome. Due to its locally destructive nature, surgery remains the mainstay of treatment. Histologically, giant cell angioblastoma is comprised of nodular aggregates of histiocytoid cells arranged around bland angiomatous spaces. Because of insufficient available data in regard to the definition of the entity, diagnostic criteria and its biological potential, it is not included in the new World Health Organization classification of tumors of soft tissue and bone. The differential diagnosis includes plexiform fibrohistiocytic tumor, myofibroma and giant cell fibroblastoma.

Congenital and infantile skin lesions affecting the hand and upper extremity, part 1: vascular neoplasms and malformations

Many dermatologic conditions may be present on a newborn infant's upper extremity that can evoke concern for parents and/or primary caregivers. Although the pediatrician typically remains the first care provider, often these children are referred to specialists to diagnose and treat these lesions. Hand surgeons should be familiar with different infantile skin lesions on an upper extremity. Some lesions are best observed, whereas others require treatment with nonoperative measures, lasers, or surgical interventions. A 2-part series is presented to aid the hand surgeon in becoming familiar with these lesions. This part 1 article focuses on vascular neoplasms and malformations. Particular attention is paid to the multiple types of hemangiomas and hemangioendotheliomas, telangiectasias, angiokeratomas, as well as capillary, venous, and lymphatic malformations. Diagnostic tips and clinical photographs are provided to help differentiate among these lesions. In addition, the recommended treatment for each is discussed.

Tufted angioma (Angioblastoma) of eyelid in adults-report of two cases

Abstract

Tufted angioma, first recognized in Japanese literature as “Angioblastoma of Nagakawa”, is a rare benign vascular tumour with a variable clinical presentation. It commonly manifests as a macule, papule or nodule in infancy or childhood in the region of the upper trunk and neck. Here in we report two cases of this rare progressive angioma as lesions of the eyelid in adults. Tufted angioma has a classical “cannon ball” like appearance of vascular tufts on histopathology. Immunohistochemical staining with actin highlights the spindly stromal cells surrounding the capillaries. Complete physical examination and haematological work up is recommended in patients with tufted angioma to exclude rare association of port wine stain and Kasabach-Merritt syndrome with this rare entity. To the best of our knowledge, our cases illustrate the first case report of tufted angioma presenting as an eyelid lesion.

Virtual Slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1230909536950947.

Report of 2 Cases of Primary Epithelioid Hemangioendothelioma of the External Iliac Vein

The epithelioid hemangioendothelioma (EHE) is a rare type of endothelial neoplasm found mainly in soft tissues and visceral organs and in extraordinary cases in large veins like the iliac veins. Currently, there is an active discussion in which EHE behavior, classification, new diagnostic tools, and treatment procedures are proposed. Here, we present 2 cases of EHE and discuss our experience in diagnosis and treatment of this neoplasm.

Cutaneous epithelioid angiomatous nodule: a case with metachronous lesions

Cutaneous epithelioid angiomatous nodule is regarded as a benign vascular proliferation on the spectrum of epithelioid vascular lesions, probably most closely related to epithelioid hemangioma. Most patients present with solitary lesions. We present an unusual case of an 84-year-old man with multiple epithelioid angiomatous nodules that developed over a 1-year period. Given the multiple lesions, an extensive evaluation for a possible infectious etiology was undertaken. However, no evidence of an infectious agent was identified. The histopathologic differential diagnosis for epithelioid vascular lesions is reviewed.

Cutaneous epithelioid angiomatous nodule of the chest wall with expression of estrogen receptor: a mimic of carcinoma and a potential diagnostic pitfall

Cutaneous epithelioid angiomatous nodule (CEAN) is a rare vascular proliferation that develops on the trunk and extremities. The lesion arises over weeks to months and affects both sexes without age predilection. Histologically, CEAN is characterized by a circumscribed proliferation of epithelioid endothelial cells in the superficial dermis with a background of lymphocytes, plasma cells and eosinophils. The epithelioid cells are positive for CD31, CD34 and/or D2-40. We report a case of CEAN that had remained stable for more than 30 years on the chest wall of a woman with a history of breast cancer. The lesional cells were epithelioid in appearance and positive for estrogen receptor (ER), raising suspicion for breast carcinoma. However, the cells were positive for CD31, CD34, D2-40 and EMA (epithelial membrane antigen); they were negative for cytokeratins, carcinoembryonic antigen (CEA), CD1a, gross cystic disease fluid protein (GCDFP-15), S-100, a melanocytic cocktail, HHV-8 and progesterone receptor. The histologic and immunohistochemical features, including a low proliferation index (10% by Ki-67), helped to distinguish this lesion from carcinoma and other vascular lesions. This is the most comprehensive immunohistochemical profile reported for CEAN to date and the first time that ER expression has been described.

Non-AIDS associated Kaposi's sarcoma: clinical features and treatment outcome

Background

Kaposi's sarcoma (KS) in HIV negative patients is rare and has to be distinguished from AIDS associated KS. Two groups are at risk to develop non-AIDS related KS: elderly men mainly of Mediterranean origin and persons with iatrogenic immunosuppression.

Patients and Methods

In order to define risk-groups and major clinical features we retrospectively evaluated clinical data of all patients with non-AIDS associated KS presenting to the Department of Dermatology, University Hospital Tuebingen between 1987 and 2009. Data were extracted from the tumor registry of the Comprehensive Cancer Center Tuebingen and from patient records.

Results

20 patients with non-AIDS KS have been identified. The average age at KS onset was 66.6 years; the male-to-female-ratio was 3∶1. Most of the patients were immigrants from Mediterranean or Eastern European countries (60%). 15 cases of classic KS versus 5 cases of iatrogenic KS were observed. In 95% of the cases, KS was limited to the skin, without mucosal, lymph node or visceral manifestation. KS lesions were in all cases multiple and mostly bilateral, the most common localization was the skin of the lower extremities. Tumor control was achieved in nearly all cases by the use of local or systemic therapy. No patient died from KS.

Conclusions

Unlike KS in AIDS patients, non-AIDS associated KS is a rather localized process which rarely involves lymph nodes or organs. It is mostly seen in elderly males from Mediterranean or Eastern European countries and in most cases responsive on local or systemic therapeutic strategies.

LMO2 promotes angiogenesis probably by up-regulation of bFGF in endothelial cells: an implication of its pathophysiological role in infantile haemangioma

AIMS

  Infantile haemangiomas (IHs) are common benign vascular tumours distinctive for their perinatal presentation, rapid growth during the first year of life and subsequent slow involution. Recent research has indicated that endothelial cells of haemangiomas express LIM-only protein 2 (LMO2). The aim of this study was to investigate the role of LMO2 in the pathogenesis of IHs was investigated.

METHODS AND RESULTS

  Immunoreactivity of LMO2 was assessed in specimens of 19 IH. Stable transfection of LMO2 into human endothelial cell lines (EAhy926) was performed to evaluate the role of LMO2 in terms of the change in cell proliferation, cell cycle and cell migration as well as the expression level of angiogenic factors. Immunoreactivity for LMO2 was detected in all IH specimens, specifically in the nucleus of the endothelial cells. The intensity of LMO2 immunostaining decreased significantly from proliferative to involuting stages. Furthermore, the overexpression of LMO2 enhanced the proliferation and migration of the endothelial cells and promoted G0/G1-S-phase transition in vitro, together with an up-regulation of bFGF expression.

CONCLUSIONS

  LMO2 probably promotes angiogenesis by up-regulation of bFGF expression and thereby consequently influences progression of IH.

Epithelioid haemangiosarcoma in the ocular tissue of horses

Haemangiosarcomas (HSAs) are malignant tumours of endothelial cell origin. Epithelioid HSA is a variant of the histologically conventional HSA that has little or no morphological evidence of a vascular origin and has been reported rarely in domestic animals. The following report documents six cases of equine epithelioid HSA occurring in the ocular tissues of horses with a mean age of 19.8 years at the time of diagnosis. Microscopically, all of the lesions consisted of solid sheets or cords of epithelioid cells with rare narrow clefts or small spaces containing erythrocytes that were often the only feature indicating a vascular origin. On immunohistochemistry, the neoplastic cells expressed vimentin, CD31 and factor VIII-related antigen, but not cytokeratin, indicating an endothelial nature.

Novel application of percutaneous cryotherapy for the treatment of recurrent oral bleeding from a noninvoluting congenital hemangioma involving the right buccal space and maxillary tuberosity

Cryotherapy is the application of varying extremes of cold temperatures to destroy abnormal tissue. The intent of this article is to describe a novel technique using percutaneous cryotherapy for treating a noninvoluting congenital craniofacial hemangioma (NICH). An 18-year-old woman with type 1 von Willebrand's disease, as well as a qualitative platelet aggregation disorder, presented with multiple recurrent episodes of oral bleeding from a NICH involving the right buccal space and maxillary tuberosity. The patient was initially treated with a combination of endovascular particulate embolization, percutaneous sclerotherapy, tissue cauterization, and laser therapy between the ages of 4 and 8 years of age. At 18 years of age, the patient presented with recurrent episodes of oral bleeding related to the NICH. Endovascular embolization was performed using particulate and a liquid embolic agent with limited success. Due to the refractory nature of this bleeding, the patient underwent successful lesion ablation using percutaneous cryotherapy. At 9-month follow-up, the patient is asymptomatic with no episodes of recurrent bleeding.

[Classification of superficial vascular anomalies]

All superficial vascular abnormalities are not angiomas even though this term continues - incorrectly - to be used. Because the suffix "oma" implies a tumor, it is necessary to differentiate true vascular tumors, such as infantile hemangioma, from vascular malformations. From a hemodynamic perspective, there are two types of vascular malformations: slow- and fast-flow. In addition to the functioning of the impaired or severely damaged vessels, we discuss slow-flow capillary, venous, or lymphatic malformations and rapid flow arterial and arteriovenous malformations. All combinations are possible. There are several types of childhood vascular tumors with different courses and different prognoses. Infantile hemangioma is by far the most frequent (8 to 10 children/100). The diverse other vascular tumors in children are sufficiently rare that they are described as orphan diseases. Since the end of the last century, a simple endothelial marker, GLUT-1, is available. This immunophenotype is present in all cases of infantile hemangioma at every stage and is negative in other tumors. Kasabach-Merritt syndrome and its accompanying severe thrombocytopenia never complicate childhood hemangioma, contrary to what has been said for nearly 60 years. When it is present, the tumor is either a tufted angioma or kaposiform hemangioendothelioma, and the GLUT1 marker can distinguish them from infantile hemangioma if the histologic diagnosis is uncertain (GLUT 1 is negative in both the latter cases). There are a wide variety of rare vascular tumors; many of them are benign, isolated, or limited; some are locally aggressive and recur after excision. A small number are low-grade malignant lesions with a risk of multivessel expansion, metastasis, and sometimes a fatal outcome. Major progress has been made in the imaging of these vascular abnormalities. Magnetic resonance imaging (MRI) in particular has revolutionized the non-invasive and especially the non-irradiating exploration of many of them. It provides information about the extent of the lesion and allows an etiological approach in many cases. Moreover, neuroradiologic evaluation of vascular cerebromeningeal lesions benefits not only from the now-standard diagnostic neurologic imaging methods of CT and MRI, but also from various advances in the techniques of functional imaging. Accordingly, for Sturge-Weber syndrome, functional imaging provides hope for an early prognosis, in particular cognitive, when these techniques are more widely used (SPECT, PET, especially the new advanced sequences of perfusion in MRI-DTI). Chronic - indeed lifelong - coagulation abnormalities, with phases of aggravation, occur in approximately half of the patients with venous malformations of the trunk and limbs, and more rarely in neck and face sites. This is not without consequences, but also not without therapeutic solutions: screening for it is therefore essential (measurement of dimer and fibrinogen levels). The discovery of gene mutations at the origin of some familial vascular malformations provides complementary data for the current classification of vascular abnormalities. It suggests that targeted therapy may be possible but probably not for quite a bit longer.

Rapidly involuting congenital hemangioma: a case of complete prenatal involution

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

Recurrent pedal hobnail (Dabska-retiform) hemangioendothelioma with forefoot reconstructive surgery using a digital fillet flap

An 8-year-old female presented with a recurrent hobnail (Dabska-retiform) hemangioendothelioma of her right foot. After initial tumor excision and subsequent recurrence, the patient underwent a successful tumor resection and forefoot reconstruction using a fillet of second digit flap. In an attempt to create a plantigrade foot, while sufficiently removing this rare pedal tumor, the authors employed the use of a fillet of second digit flap. Specific surgical techniques and the histopathological assessment of this rare vascular neoplasm are discussed.

LEVEL OF CLINICAL EVIDENCE

4.