Elastofibroma: clonal fibrous proliferation with predominant CD34-positive cells

Focal Oral Elastosis: Case Series, Proposed Nomenclature, and Literature Review

ABSTRACT

Late-onset focal dermal elastosis is an uncommon elastic disorder seen in older individuals and biopsies demonstrate an increase in elastic fibers. Elastosis of the oral cavity is reported uncommonly. The aim of this study is to describe oral biopsies with similar histopathologic features to late-onset focal dermal elastosis and to introduce the term "focal oral elastosis." We included oral biopsies that showed increased elastic fibers confirmed by Verhoeff-van Gieson histochemical stain. We identified 6 oral biopsies with prominent elastosis. There were 4 men, and the median age was 64.5 years. Elastosis was present in 5 nodular lesions and 1 papule. Lesions occurred on the gingiva (33.3%), palatal mucosa (33.3%), buccal mucosa (16.7%), and upper lip (16.7%). Deposition of amorphic bluish/amphophilic material in the subepithelial areas was seen in all cases confirmed with the Verhoeff-van Gieson stain. Our case series demonstrates the presence of elastic fibers in reactive lesions such as oral fibromas.

Appendiceal Elastofibroma Requiring Ileocecectomy

Elastrofibromas are rare lesions characterized by collagen and elastic fiber deposition. They are generally found in soft tissues and throughout the gastrointestinal tract. The pathogenesis of this lesion is still uncertain, but it is hypothesized to be a reactive process. We present a case of an appendiceal elastofibroma, a unique anatomic location that necessitated surgical removal, with pathologic findings suggestive of an inciting event from a sclerosed vascular abnormality.

[Elastofibroma dorsi: Diagnosis and follow-up in primary care]

OBJECTIVE

To present a series of patients with elastofibroma dorsi (ED) in order to recall the pathology and justify its diagnostic and therapeutic management in the primary care setting.

MATERIALS AND METHODS

Retrospective observational and longitudinal study of 12 patients with 18ED. Epidemiological, clinical and imaging characteristics were analysed. Treatment outcomes were assessed in terms of pain (VAS scale), shoulder function (Constant and Murley scale) and quality of life (EuroQol-5 dimension scale, EQ-5D). The mean follow-up of the cases was 60.5months (5years, range 1-161months).

RESULTS

Six patients were male and six were female, with a mean age at diagnosis of 59years. The diagnosis of suspicion in all cases was based in clinical and imaging findings. Only three required surgery. The results of all were satisfactory.

CONCLUSIONS

Both the diagnosis and the indication for treatment of an ED can be made in the primary care setting. In typical cases, which are the majority, the clinical history and an ultrasound study allow a diagnosis of certainty. The indication for conservative or surgical treatment depends on the informed patient. When there are diagnostic doubts or the patient wishes surgical resection of the tumour, the patient should be referred to a hospital specialist.

Bilateral Elastofibroma Dorsi: A Case From General Practice

Elastofibroma is a benign soft tumor that is composed of elastic fibers in a background of collagenous and adipose tissue. However, the presence of multiple elastofibromas is considered a rare occasion. We report the case of a 39-year-old man who presented to our general practice clinic with a complaint of upper back swelling for the last three months. The swelling was completely painless. It was not associated with ulceration of the overlying skin. He reported that the swelling had not been increasing in size. There was no history of anorexia, weight loss, or preceding trauma. On examination, both shoulders had a normal range of motion with no restriction due to the mass lesions. To further characterize the mass lesions, the patient underwent a computed tomography scan of the thorax. It demonstrated bilateral lenticular subscapular mass lesions that were ill-defined but had similar attenuation to that of adjacent skeletal muscle along with the presence of interspersed streaks of fat. Such findings represent the diagnosis of elastofibroma. However, the patient was concerned about the possibility of the malignant nature of these lesions and insisted on having the surgical resection of the mass. The histopathological findings confirmed the diagnosis of elastofibroma. Elastofibroma is a benign soft tissue tumor that is diagnosed incidentally in the majority of cases. However, multiple elastofibroma, as in the present case, is considered unusual. The case demonstrated the radiological and histopathological features of elastofibroma. The imaging findings are characteristics and can prevent unnecessary biopsy or surgical intervention. However, if clinically indicated, surgical resection is considered curative.

Elastofibroma Dorsi, a Rare Condition, with Challenging Diagnosis. Case Report and Literature Review

Elastofibroma dorsi (ED) is known as a particular clinical and biological entity. We report a case of a bilateral elastofibroma dorsi (ED) in a 65-year-old female who presented to the Department of General and Oncologic Surgery of Emergency Clinical Municipal Hospital Timisoara, Romania. The patient was symptomatic on the right side, presenting pain in the interscapulothoracic region associated with a variable tumoral mass, dependent on the position of the right arm. Imaging studies revealed a well-defined, bilateral tumoral mass with alternation of the muscular and fatty tissue. The initial diagnosis of lipoma was taken into consideration based on the CT scan and clinical findings. Surgical excision of the right subscapular tumor was performed without any postoperative complications. Microscopic examination of hematoxylin and eosin, Masson’s trichrome, and orcein stained slides revealed the diagnosis of ED. Considering the high rate of reported postoperative complications and the asymptomatic presentation of the contralateral subscapular mass, the patient underwent clinical and imagistic monitoring for the contralateral tumor. Due to its rare nature, ED is a difficult preoperative diagnosis that can, however, be suggested by its specific location and may require an accurate histopathological examination for a final diagnosis.

Abdominal elastotic lesions. A clinicopathologic study of 23 cases

Abdominal elastotic deposits are uncommon lesions that often presents as polyps. They show three histological patterns: fibroelastosis, angioelastosis, and elastofibroma. We describe 23 cases including rare locations, such as mesentery, greater omentum, hernia sac, spleen, peripancreatic fat, and hypodermal fat. The age of the patients ranged from 49 to 93 years (mean, 76.8 years). Most lesions were discovered incidentally in the microscopic study. The most frequent locations were peritoneal subserosa (43.5%) and mesentery/mesocolon/greater omentum (39.1%). The most common pattern was fibroelastosis (69.6%) followed by angioelastosis (26.1%). We observed one case of omental elastofibroma. A review of the 14 abdominal elastofibromas described including our case revealed that the age of the patients ranged from 45 to 88 years (mean, 68.5 years). Female predominance is striking (M:F, 1:12). The most common site was the stomach (50%). The greater omentum (14.3%), small intestine (7.1%), and pancreas (7.1%) are very rare sites for this lesion. Only one case before ours has been published in the greater omentum. The size of the lesions ranged from 0.7 cm to 8 cm (mean 3.2 cm). In 36.4% of the cases located in the digestive tract, the mucosa did not show alterations. Ulcerations (36.4%) or polypoid excrescences (18.2%) were mostly observed. Six (42.9%) cases were asymptomatic and six (42.9%) cases simulated a neoplasm. Two cases were associated with elastofibromas in other locations. Differential diagnosis includes amyloidoma, elastofibrolipoma, mesenteric elastic vascular sclerosis in neuroendocrine tumors, diverticular disease elastosis, pseudoxanthoma elasticum, pulse granuloma, and digestive lesions in patients treated with D-Penicillamine.

Surgery for elastofibroma dorsi: optimizing the management of a benign tumor-an analysis of 70 cases

Background

Elastofibroma dorsi (ED) is a benign soft-tissue tumor of the chest wall located near the tip of the scapula. Clinical presentation includes swelling, pain and impairment of shoulder movements. The present literature relies only on few small case series. The aim of this study was to analyze the surgical management of ED, focusing on the debated topics regarding preoperative evaluation, operative technique, post-operative outcome and follow-up.

Methods

We conducted a single-center retrospective cohort analysis of patients operated for ED between 2003 and 2018. Diagnostic techniques were ultrasonography (US), computed tomography (CT-scan) and magnetic resonance imaging (MRI). CT-scan represented our preferred imaging study for preoperative assessment. Surgery was proposed for symptomatic and/or large lesions. Marginal excision through a muscle-sparing approach was performed. An open-door follow-up policy was adopted. All clinical, radiological, perioperative and pathological variables were matched in a univariate analysis. A multivariate analysis was performed to investigate risk factors for postoperative complications. Correlations analysis between radiological and pathological measurements of elastofibroma was conducted.

Results

Seventy elastofibromas were excised in 59 patients. Mean age was 59 years and female prevalence was 59%. All elastofibromas were completely resected with no recurrence. Postoperative complications rate was 17%. Complications were mild in most cases. At the univariate analysis, patients with body mass index (BMI) >25 had a longer operative time (P=0.048), patients on antiplatelet medications experienced a prolonged drainage time (P=0.006) and a higher rate of complications (P=0.038); the occurrence of complications resulted in prolonged drainage time (P=0.047) and length of stay (P=0.023). A BMI ≤25 was the only independent risk factor for postoperative morbidity (OR 8.71, P=0.024). CT-scan showed the highest correlation with pathological size (r=0.819), US the lowest (r=0.421).

Conclusions

Marginal resection through a muscle-sparing approach is safe and effective for the treatment of ED. CT-scan can be adequate for preoperative assessment. Giving the benign nature of the lesion and the absence of recurrence after complete resection, an open-door follow-up may be appropriate.

Elastofibroma Dorsi: A Rare Connective Tissue Tumor

Elastofibroma dorsi (ED) is a benign connective tissue tumor that most commonly occurs on the inferior pole of the scapula. It can be found incidentally on radiologic imaging or due to clinical symptoms. Patients may become apprehensive due to it mimicking new malignancy or recurrence of prior malignancy. Treatment is only recommended in symptomatic cases and biopsy is usually unnecessary. We present a case of a 70-year-old female status-post lung cancer resection who was found to have a lump at the inferior pole of her right scapula. She was seen by multiple different specialties and subsequently, a biopsy confirmed her mass to be consistent with ED. Since ED is a benign soft tissue tumor, educating physicians is of utmost importance to avoid pursuing unnecessary diagnosis and to thereby decrease the cost of care to the patient. Therapeutic excision should only be performed in symptomatic patients and observing these lesions in asymptomatic patients would be sufficient.

Comparison of CD34 expression in fibrous reactive hyperplasia and healthy oral mucosa

OBJECTIVES

Fibrous reactive hyperplasia (FRH) is a common fibrous lesion in the oral cavity. The disease characteristics of FRH, including the expression patterns of CD34, which is a well-known fibroblast marker, have not been investigated in detail. Therefore, in this study, we aimed to investigate the characteristics of FRH compared to those of the healthy mucosa, based on CD34 expression profiles.

METHODS

CD34 expression was analyzed at the protein and mRNA levels using immunohistochemistry, quantitative polymerase chain reaction, and in situ hybridization (ISH).

RESULTS

CD34 was not expressed in the lamina propria of the oral mucosa, but was commonly observed in submucosal fibroblasts. CD34-positive fibroblasts were commonly observed in FRH. A total of 17 out of 19 cases (89.5%) were CD34-positive. Furthermore, we identified a significant difference in the ratio of CD34-positive cells between the healthy and FRH tissues. Quantitative polymerase chain reaction showed that CD34 mRNA was expressed in all cases of FRH, and CD34 mRNA expression in FRH samples was found to be localized to spindle-shaped fibroblasts, as determined by ISH. A positive correlation was also found between the CD34 mRNA levels and the proportion of the CD34-positive cells.

CONCLUSIONS

These findings suggest that the increase in collagen synthesis in CD34-positive fibroblasts in the submucosa leads to the development of FRH. To our knowledge, this is the first report confirming the mRNA expression patterns of CD34 in FRH.

Concomitant bilateral elastofibroma in the infrascapular and gluteal regions: a report of a rare case

BACKGROUND

Elastofibroma is a benign soft tissue tumor characterized by the presence of elastic fibers in a stroma of collagen and mature adipose tissue. It is reported to have a prevalence of 2.73%, as shown by a study through computed tomography (CT) images. However, multiple elastofibromas are uncommon.

CASE PRESENTATION

We report a case of concomitant bilateral elastofibroma in the infrascapular and gluteal regions. A 63-year-old male patient presented with a 6-month history of gradually increasing painless swellings in the upper back. On physical examination, firm, painless bilateral infrascapular masses were identified; these masses were more noticeable on forward arm flexion. Contrast-enhanced computed tomography showed well-defined bilateral infrascapular masses deep to the serratus anterior muscles as well as poorly defined bilateral gluteal masses with attenuation similar to that of the adjacent skeletal muscle. Magnetic resonance imaging revealed heterogenous masses with internal fatty streaks, consistent with elastofibroma. The histopathological diagnosis of elastofibroma was established based on the results of image-guided core-needle biopsy. The patient underwent surgical excision of both infrascapular elastofibromas with no post-operative complications. As the gluteal masses were incidental, surgical management was not warranted.

CONCLUSION

The presence of multiple elastofibromas is unusual. This report describes a rare case of multiple elastofibromas and its typical imaging features, and alerts us that elastofibromas are not exclusive to the periscapular region.

[Elastofibromatous polyps of the gastrointestinal tract: report of three cases and review of the literature]

INTRODUCTION

Gastrointestinal elastofibromatous polyps are rare benign lesions. In 1985, Enjoji described elastofibromatous change of the stomach but since only isolated cases have been reported, with none in Spanish language journals. They present as single, usually asymptomatic, polypoid lesions, most frequently in the large intestine. Biopsy is essential for diagnosis and the main differential diagnosis is amyloidosis.

OBJECTIVE

To report the clinicopathological characteristics of a new series of gastrointestinal elastofibromatous polyps and review the pertinent literature.

PATIENTS AND METHODS

A retrospective study of cases of elastofibromatous polyps diagnosed between 2016 and 2017 in the Hospital Clínico de la Universidad Católica de Chile. Demographic data and histological slides stained with H&E, Verhoeff - van Gieson histochemical staining and Congo-red, were reviewed as well as previously reported cases.

RESULTS

3 cases of gastrointestinal elastofibromatous polyps were found, all located in the large intestine. The location of 41 previously reported cases was: 34 (77%) in the large intestine; 6 (14%) in the stomach and 4 (9%) in the small intestine.

CONCLUSIONS

Our findings concord with previously reported cases. As they are rare lesions, careful histopathological examination, complemented with histochemical studies, is necessary for a correct differential diagnosis, ruling out other possibilities, such as amyloidosis, with different clinical implications.

Elastofibroma dorsi

We present a 60-year-old man with biopsy-proven metastatic squamous cell carcinoma of the right inguinal and external iliac lymph nodes with unknown primary. Hypermetabolic soft tissue masses were identified in bilateral subscapular regions on follow-up positron emission tomography (PET)-computed tomography (CT) after completion of chemoradiation. The right subscapular mass was biopsied under CT guidance, and histopathology showed it to be elastofibroma dorsi. Elastofibroma dorsi is a benign tumor with no malignant potential; due to its ill-defined appearance and tracer uptake on PET-CT, it can be misdiagnosed as soft tissue sarcoma. This report describes the typical location and imaging features of this incidental hypermetabolic mass.

Onychomatricoma: A Rare Tumor of Nail Matrix

Onychomatricoma is a rare tumor of the nail matrix. Until now, few cases of onychomatricoma have been reported in the literature. Immunohistochemically, CD10, a marker of the onychodermis, is expressed in the stroma of the onychomatricoma. In the present case, a 27-year-old woman presented with an 8-year history of a yellowish, thickened, and overcurved nail plate of the right index finger, mimicking onychomycosis. She had been treated for 4 years with antifungal agents by general physicians, without improvement. The nail was surgically removed, and the tumor at the nail matrix was excised. The nail plate continued to grow in the 2 months after the excision. This is a case of onychomatricoma in South Korea, which was initially misdiagnosed as onychomycosis. In addition, we present a review of the literature regarding clinical, sonographic, and histological features, differential diagnoses, and treatment of onychomatricoma.

Elastofibroma dorsi and the thoracic surgeon: experience with 13 patients

A total of 13 patients (11 females, average age of 63 years) with elastofibromadorsi were retrospectively analyzed. The disease was confirmed by surgical intervention in five cases. In other patients (n = 8) the diagnosis was achieved on the basis of clinical and radiological features. Typical imaging features allow for the diagnosis of elastofibromadorsi. Symptomatic lesions need to be surgically removed, whereas asymptomatic ones could be clinically and radiologically monitored.

Elastofibroma dorsi: a histochemical and immunohistochemical study

Elastofibroma dorsi (ED) is considered a member of a heterogeneous group of benign fibrous (fibroblastic or myofibroblastic) softtissue tumors, frequently localized in the periscapular region in middle aged or older individuals. However, the pathogenesis of ED is still unclear and many authors believe that ED results from a reactive hyperproliferation of fibroblastic tissue, while others suggest that it may be a consequence of a mechanical friction. In our study, we examined 11 cases of ED using histochemical and immunohistochemical methods, in order to extend the knowledge about extracellular matrix composition and histopathogenesis of ED. From the results it appeared that stroma and interspersed spindle cells of ED were positive for both periostin and tenascin-C. Mast cells tryptase-positive were also abundant throughout the lesion. The perivascular distribution of periostin and tenascin-C, associated with the CD34 positivity, suggest that endothelial-mesenchymal transition events can account for neovascularization and production of fibroelastic tissue characteristic of elastofibroma. Our data obtained in endothelial cells cultures demonstrated that elastin production is higher when the status of confluence of the cells is low. So, we can assume that such a phenomenon is a characteristic of mesenchymal/endothelial cells CD34 positive, in which elastin production results to be inversely proportional to the vascular differentiation of cellular elements. In the light of these considerations, we think that a cancerous nature of ED is unlikely. Overall, our study report, for the first time, a detailed description of extracellular matrix composition in ED, suggesting that a mechanical strain-dependent reactivation of periostin and tenascin-C expression, as well as of elastin deposition, could be responsible for development of ED.

Elastofibroma dorsi: Surgical indications and complications of a rare soft tissue tumor

Elastofibroma dorsi (ED) is a tumor that develops in the space between the lower angle of the scapula and the posterior thoracic wall. Due to the rarity of this type of tumor, the number of reported consecutive series is limited. Surgical excision, usually recommended for symptomatic cases to confirm diagnosis and relieve symptoms, has been associated with a high complication rate. To analyze the clinical characteristics and outcomes of surgical treatment, we retrospectively reviewed 20 consecutive cases of surgically resected ED. Of the 20 patients, 14 (70%) exhibited preoperative symptoms associated with the tumor. The mean diameter of the resected tumors averaged 72 mm (range, 45-110 mm). The surgical outcomes were satisfactory, except for the development of hematoma or seroma in 9 cases (43%), 8 of which achieved a complete resolution with conservative treatment. Age, hypertension, the presence of preoperative tumor-related symptoms and intraoperative bleeding were not found to be significantly associated with the incidence of hematoma. However, tumor diameter and the duration of postoperative drainage were significantly associated with occurrence of hematoma (P=0.02 and P=0.01, respectively). Surgical resection should only be recommended for symptomatic patients, due to the high incidence of postoperative complications. To prevent the development of postoperative hematoma or seroma, careful observation of the wound, with suction drainage for >7 days and additional surgical procedures to facilitate adhesion of the wound margins, are recommended.

Elastofibroma dorsi: diagnostic and therapeutic algorithm

BACKGROUND

Elastofibroma typically occurs in the subscapular region of elderly individuals and has a high incidence in Kyushu and the surrounding islands in southern Japan. The treatment of this lesion is somewhat controversial.

PATIENTS AND METHODS

Eleven patients with a diagnosis of elastofibroma dorsi were identified from the unit's database. The clinical presentation, diagnosis, and treatment options were evaluated.

RESULTS

There were 6 men and 5 women, with a mean age of 66.7 years (range, 49-82 years). Bilateral lesions were found in 2 patients. The mean lesion size was 6.6 cm in greatest dimension (range, 5-9 cm). The mean follow-up of both surgically and conservatively managed patients was 16.4 months (range, 2-69 months). All were diagnosed by magnetic resonance imaging, and early in the series, 1 also underwent an open biopsy to confirm the diagnosis. Five patients underwent marginal excision of the lesion. No recurrence was observed at last follow-up.

CONCLUSIONS

Magnetic resonance imaging can be used as a first-line investigation of the lesion, and biopsy is not necessary in most cases. We suggest that a conservative "wait-and-watch" attitude is reasonable and may be considered even when patients are symptomatic.

Elastofibromatous changes and hyperelastosis of the oral mucosa

Three cases of abnormalities of elastic fibers, two of them on the floor of the mouth and one on the lingual alveolar mucosa, close to the floor of the mouth, in a patient with history of homolateral squamous cell carcinoma of the floor of the mouth, are presented. Comparison with elastofibromatous changes and elastofibromas are made and their possible pathogenesis is discussed. It is suggested that increased awareness may facilitate recognition of such lesions as they can be easily overlooked, especially when they do not present as discrete tumors or they are associated with other "more significant" pathologic processes.

An Ultrastructural and Immunohistochemical Study of Elastofibroma: CD 34, MEF-2, prominin 2 (CD133), and Factor XIIIa-positive Proliferating Fibroblastic Stromal Cells Connected by Cx43-type Gap Junctions

Elastofibromas have been described as ill-defined tumors, composed of fibroblastic stromal cells and a dense collagenous stroma. A total of 5 elastofibromas from 4 Japanese patients were examined by ultrastructural and immunohistochemical methods. The proliferating fibroblastic stromal cells in the lesion showed Cx43-type gap junctions, isolated cilia, prominent nuclear fibrous laminae, and primitive cellular junctions with incomplete laminae. The active proliferating fibroblastic cells showed positive staining for vimentin, CD34, factor XIIIa, prominin 2 (CD133), and MEF 2. Conspicuous cell-to-matrix interactions were observed with abnormally unique elastins, collagens (type I, III, and IV), laminin, fibronectin, and amorphous extracellular matrix (GAGs; glycosaminoglycans). As for the origin of elastofibromas, the tumors in the present study were suggested to arise from subscapular or periosteal connective tissue, but further revealed some similarities to other tissues, such as human skin dermal tissue, as exemplified by the presence of an abundance of type I and III collagen, CD34/factor XIIIa-expressing stromal fibroblast-like cells, amorphous extracellular matrix, and a unique abnormal elastin. The elastofibromas might have arisen from stromal stem cell candidate populations of stromal fibroblastic cells (CD34(+), MEF2(+), prominin 2(CD133)(+), and factor XIIIa(+)).

Elastofibromatous Changes in Tissues From Spinal Biopsies. A Degenerative Process Afflicting a Small but Important Subset Of Patients Operated for Spinal Canal Compression: Report of 18 Cases

Elastofibroma is a tumorlike lesion occurring usually in the subscapular region of elderly females. In this study, 18 cases of elastofibromatous tissue retrieved from the spinal canal were analyzed to elucidate its frequency and possible clinical associations. The patients included 8 men and 10 women with a mean age of 63.4 years (range, 40-84 years). The elastic nature of the material was confirmed by Weigert’s elastic stain and immunohistochemically. Elastofibroma was diagnosed in 6 patients, and elastofibroma-like tissue was found in 11 samples. The finding of elastofibromatous tissue was associated with clinical diagnosis of juxtaarticular cysts (3 cases), thickening of ligamentum flavum (4 cases), extradural expansion (2 cases), metastatic involvement of the dorsal spine (3 cases), and a vertebral fracture (1 case). Two cases were located above the transpedicular fixation. Elastofibromatous tissue may be found in approximately 2.6% of all spinal biopsies and it may take part in compression of spinal cord and nerve roots.

Elastofibroma: Diagnosis and Treatment of Six Cases

Elastofibroma is a rare, benign pseudotumor that arises from connective tissue, most commonly found at the right scapular tip. These tumors usually can be distinguished from malignant soft-tissue tumors by their anatomical location and also through imaging techniques. Although elastofibroma is rare, it is important for surgeons to be aware of this diagnosis to prevent unnecessary biopsies and unnecessary operations. We report a series of six patients, four of whom were female, with a median age of 62.5 years, diagnosed with and treated for elastofibroma. Five of the six patients had unilateral lesions, while one patient had bilateral elastofibromas. All unilateral lesions were found on the right side. The elastofibroma in five of six patients was located on the subscapular tip, the remaining patient's elastofibroma was found on the chest wall external to the pleural surface. The pathogenesis of this lesion is discussed, as recent evidence suggests a neoplastic origin to elastofibroma. Additionally, cellular changes occurring in elastofibroma may reflect the pathogenesis of other disorders of elastic fibers.

Active neovascularization and possible vascular-centric development of gastric and periscapular elastofibromas

An elastofibroma is a benign and rare fibrous lesion that most commonly occurs in the periscapular region. A gastrointestinal elastofibroma is extremely rare. In the present study, six cases of elastofibromas including a case in the stomach were evaluated. The gastric case revealed widely distributed lesions in the submucosal layer with perivascular fibrotic lesions (PVFLs) and some PVFLs were distributed to the skip lesions of elastofibroma. These PVFLs were also observed in all five periscapular cases and invariably contained elastic fibers which showed various degree of maturation. CD34-positive stromal cells were observed not only in elastofibromas but also in PVFLs in each case. These findings suggested the possibility of the PVFLs were the primary lesions of elastofibroma and their vascular-centric development. The percentage of the CD105-positive vessels in elastofibroma group was significantly higher than in the control group. This result indicates active neovascularization in elastofibromas.

Pathologic and MR Imaging Features of Benign Fibrous Soft-Tissue Tumors in Adults

Benign fibrous (fibroblastic or myofibroblastic) soft-tissue tumors are a heterogeneous group of fibrous lesions with widely varied anatomic locations, biologic behavior, and pathologic features. The four broad categories of fibrous proliferation are benign fibrous proliferations, fibromatoses, fibrosarcomas, and fibrous proliferations of infancy and childhood. The first two categories include nonaggressive fibroblastic lesions such as nodular fasciitis, as well as fibromatoses that demonstrate more aggressive biologic behavior (eg, desmoid tumors). In adults, fibrous tumors are among the most common soft-tissue lesions encountered in clinical practice. MR imaging can be useful for defining the intrinsic signal characteristics, size, and compartmental extension of these lesions. Histologic features of the tumor also may be depicted on T2-weighted MR images. Hypocellular fibrous tumors with dense collagenous components tend to have lower signal intensity on T2-weighted images than do lesions that are more cellular or that contain greater amounts of extracellular myxoid matrix. When interpreting MR images of soft-tissue masses in adults, radiologists should be aware of the clinical behavior, common sites of occurrence, and histopathologic and imaging features of the common benign fibrous soft-tissue tumors.