Alveolar soft part sarcoma-radiologic patterns in children and adolescents

Alveolar soft part sarcomas in young patients: The French national NETSARC+ network experience

BACKGROUND AND AIMS

Alveolar soft part sarcoma (ASPS) is an ultra-rare chemo-resistant sarcoma in children, occurring preferentially in young adults. We aimed to describe and compare its clinical presentation and behaviour in children and young adults to determine whether the same therapeutic strategy should be addressed for both populations.

METHODS

National retrospective multicentre study of children (0-18 years) vs. young adults (19-30 years) included in the "ConticaBase" sarcoma database, treated for ASPS between 2010 and 2019 with pathology reviewed via the NETSARC + network.

RESULTS

Overall, 45 patients were identified, 19 children (42%) and 26 young adults (58%). All ASPS diagnoses were confirmed with TFE3 rearrangement by immunohistochemistry or FISH. All clinical characteristics were balanced between both populations with frequent metastases at diagnosis (8/19 vs. 10/26). The therapeutic strategy was based on surgery (17/19 vs. 21/26), radiotherapy (8/19 vs. 12/26) ± systemic treatment (8/19 vs. 9/26). In patients with initially localized disease, metastatic relapse occurred only in adults (8/16), whereas metastatic progression was present in both metastatic groups (5/8 vs. 8/10). After a median follow-up of 5.2 years (range, 0.2-12.2), 5-year EFS was 74% [95%CI, 56-96] vs. 47% [30-74] (p = 0.071) respectively, and 5-year OS was 95% [85-100] vs. 85% [70-100] (p = 0.84). For localized tumours, 5-year MFS was 100% [100-100] vs. 60% [39-91] (p = 0.005). The 5-year OS of all patients with metastasis at diagnosis was 80.2% (62.2%-100%).

CONCLUSIONS

ASPS appears to have the overall same clinical characteristics, but a more aggressive behaviour in young adults than in children. However, despite frequent metastases at diagnosis, long-term survival is high in both groups. Overall, the same therapeutic strategies may be considered for both populations.

Imaging Features of Alveolar Soft Part Sarcoma: Single Institution Experience and Literature Review

Alveolar soft part sarcoma (ASPS) is an extremely rare and aggressive soft-tissue sarcoma (STS) subtype with poor prognosis and limited response to radiation therapy and chemotherapy. Prompt recognition and referral to sarcoma centers for appropriate management are crucial for patients' survival. The purpose of this study was to report ASPS pre-treatment imaging features and to examine the existing literature on this topic. Twelve patients (7 women, 5 men-mean age 27.1 ± 10.7 years) were included from our single-center experience. Ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) available were reviewed according to an analysis grid incorporating features from the latest research on STS. Clinical, histological, and outcome data were collected. MRI was available in 10 patients (83.3%), US in 7 patients (58.3%), and CT in 3 patients (25%). Mean longest tumor diameter was 7.6 ± 2.9 cm, and all tumors were deeply seated. Large peritumoral feeding vessels were systematically found and identified on ultrasonography (7/7), MRI (10/10), and CT (3/3). US revealed a well-defined heterogeneous hypoechoic pattern, with abundant flow signals in all patients (7/7). In all patients, MRI showed mildly high signal intensity (SI) on T1-WI and high SI on T2-WI and peritumoral edema. Moreover, flow-voids (due to arteriosus high-flow) into the peritumoral/intratumoral feeding vessels were detected in the MRI fluid-sensitive sequences of all patients. At baseline, whole-body contrast-enhanced CT revealed metastases in 8/12 (66.7%) patients. A pre-treatment longest diameter > 5 cm was significantly associated with distant metastases at diagnosis (p = 0.01). A maximum diameter > 5 cm represents a risk of metastatic disease at diagnosis (odds ratio = 45.0000 (95% CI: 1.4908-1358.3585), p = 0.0285). In the comprehensive literature review, we found 14 articles (case series or original research) focusing on ASPS imaging, with a total of 151 patients included. Merging our experience with the data from the existing literature, we conclude that the hallmark of ASPS imaging at presentation are the following characteristics: deep location, a slight hyperintense MRI SI on T1-WI and a hyperintense SI on T2-WI, numerous MRI flow voids, high internal vascularization, and large peritumoral feeding vessels.

Alveolar Soft Part Sarcoma of Hypopharynx; A Case Report

Alveolar soft part sarcoma (ASPS) is an aggressive soft-tissue malignancy, notorious for its metastasis to other tissues. A considerable number of cases in the head and neck have been reported but not in the hypopharynx. We describe a 31-year-old man with an incidental finding of a hypopharyngeal mass. Flexible laryngoscopy revealed a fleshy mass 2 × 2 cm² originating from the left hypopharynx and overlying the epiglottis. Computed tomography scan demonstrated a soft tissue mass in the left wall of the oropharynx measuring about 2.2 × 1.8 cm², projecting into the hypopharyngeal air space. Magnetic resonance imaging showed a significant thickening of the left hypopharyngeal wall forming a mass lesion occupying the left pyriform sinus and abutting the left aryepiglottic fold. Histopathology indicated that tumor cells were polygonal and epithelioid, with abundant eosinophilic to clear flocculent cytoplasm, eccentric nuclei, and prominent nucleoli. The tumor was positive for smooth muscle actin with rare cells staining for Human Melanoma Black (HMB45). Fluorescence in situ hybridization for transcription factor E3 was also performed and supported the above diagnosis. Our study reports the first case of ASPS in the hypopharynx.

Alveolar soft part sarcoma of the superior rectus muscle: Case report and review of literature

Purpose

Alveolar soft part sarcoma (ASPS) is a very rare type of soft tissue sarcomas which usually occurs in the limbs and trunk.

Observations

A 25-year-old woman presented with proptosis and redness of the right eye for 8-month. She suffered from severe right upper lid edema, conjunctival chemosis, downward displacement of the globe, and proptosis. Radiological imaging was nonconclusive. Histopathological evaluations confirmed ASPS. The patient underwent exenteration as a lifesaving procedure. At 16-month follow-up, the patient is stable without any signs of recurrence or metastasis.

Conclusions and importance

We report an extremely rare case of ASPS occurring in the superior rectus muscle. Few orbital ASPS cases have been reported in the literature. A literature review of orbital ASPS was done to shed lights on the diagnosis and management of this rare tumor.

Imaging and Pathological Features of Alveolar Soft Part Sarcoma: Analysis of 16 Patients

Context  Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor most commonly occurring in deep intramuscular plane of lower extremities of adolescents and young adults. It is a highly vascular, slow growing tumor with malignant potential having lung as the most common site of metastases at the time of presentation. Aims  The aim is to review the imaging findings of ASPS and determine characteristic imaging features of this rare tumor. Materials and Methods  Sixteen patients having histopathological diagnosis and preoperative imaging of ASPS attending the dedicated sarcoma clinic at our institute were included in the study. The demographic, clinical, and imaging data were retrieved from the case records and then evaluated for characteristic imaging features which may raise suspicion of ASPS. Results  The patients ranged from 3 to 72 years of age and with a slight male preponderance. Of the eight CECTs evaluated, 62.5% tumors showed well-defined lobulated margins, 87.5% cases showed intense enhancement with presence of feeder vessels. On CEMRI of 10 patients, 70% had well circumscribed lobulated margins with intense enhancement and tortuous flow voids in most of them. All cases showed T2 hyperintense signal. Fourteen of 16 (87.5%) patients had metastatic disease with lung as the most common site (92.8%). Conclusion  ASPS is a rare soft tissue sarcoma seen in children and young adults. Imaging may mimic a vascular malformation due to the presence of tortuous feeders. Misdiagnosis at an early stage may lead to later metastatic presentation of the disease, thus emphasizing the need to suspect it on imaging.

Imaging of Soft Tissue Tumors

Differentiation of malignant from benign soft tissue tumors is challenging with imaging alone, including that by magnetic resonance imaging and computed tomography. However, the accuracy of this differentiation has increased owing to the development of novel imaging technology. Detailed patient history and physical examination remain essential for differentiation between benign and malignant soft tissue tumors. Moreover, measurement only of tumor size based on Response Evaluation Criteria In Solid Tumors criteria is insufficient for the evaluation of response to chemotherapy or radiotherapy. Change in metabolic activity measured by ¹⁸F-fluorodeoxyglucose positron emission tomography or dynamic contrast enhanced-derived quantitative endpoints can more accurately evaluate treatment response compared to change in tumor size. Magnetic resonance imaging can accurately evaluate essential factors in surgical planning such as vascular or bone invasion and "tail sign". Thus, imaging plays a critical role in the diagnosis and treatment of soft tissue tumors.

Management of sarcomas in children, adolescents and adults: Interactions in two different age groups under the umbrellas of GSF-GETO and SFCE, with the support of the NETSARC+ network

Sarcomas are a rare heterogeneous group of malignant neoplasms that can arise in almost any anatomic site and any age. Close collaboration among adult and pediatric cancer specialists in the management of these tumors is of foremost importance. In this review, we present the current multidisciplinary organization in care of patients with sarcoma in France and we review the main advances made in the last decades in systemic and radiotherapy treatment in the main sarcoma types diagnosed in children, adolescents and young adults (AYA), thanks to the international collaboration.

iCREATE: imaging features of primary and metastatic alveolar soft part sarcoma from the EORTC CREATE study

Background

Alveolar Soft Part Sarcoma (ASPS) is a rare, slow-growing, but highly vascular soft tissue sarcoma, characterised by a high rate of metastases at presentation. Although imaging features of the primary are well described, less detail is available on the imaging pattern of metastatic ASPS. The EORTC 90101 (CREATE) study assessed the efficacy of Crizotinib in patients with metastatic ASPS and presents a unique opportunity to describe the imaging phenotype of primary and metastatic ASPS, based on prospectively collected imaging.

Methods

A retrospective review of the staging CT scans of 32 patients with ASPS from the CREATE study was undertaken and the imaging features of primary and metastatic disease were assessed.

Results

Imaging of the primary tumour was available in 7/32 cases (28%). All primary tumours demonstrated marked vascularity with prominent feeding vessels (7/7, 100%). The most frequent sites of metastases included lung (30/32, 94%), nodal (7/32, 22%), bone (5/32, 16%) and muscle/subcutaneous (5/32, 16%). Features of hypervascularity were identified at all sites, more appreciable in the lungs, with feeding vessels frequently demonstrated in pulmonary metastases (21/32, 66%).

Conclusion

Analysis of imaging from the CREATE cohort of patients with metastatic ASPS demonstrates that metastases from ASPS are predominantly hypervascular and demonstrate feeding vessels comparable to primary ASPS, suggesting potential sensitivity of this rare sarcoma for antivascular/antiangiogenic treatment approaches.

Alveolar soft part sarcoma of the lateral rectus muscle: Suture technique to prevent postoperative strabismus

Purpose

We present a rare case of intramuscular alveolar soft part sarcoma (ASPS) of the lateral rectus (LR) muscle and the surgical technique used to maintain orthotropia after complete resection of the mass.

Observations

A 5-year-old boy presented with progressive proptosis of the left eye due to an orbital tumor. The patient was previously diagnosed with ASPS of the left LR muscle from an incisional biopsy, and the tumor size increased despite 5 cycles of chemotherapy prior to presenting to our center. Magnetic resonance imaging showed a 28x19x15mm-sized contrast-enhancing intramuscular mass of the left LR muscle, and there was no evidence of nodal or distant metastasis. The mass was excised en bloc, along with the insertion and the posterior normal part of LR muscle. To maintain proper eye alignment after resecting LR muscle, a 4-0 Prolene® hang-back suture was placed between the scleral insertion and the periorbita of the posterior orbit and the left medial rectus muscle was injected with botulinum toxin. During the follow-up of 51 months after surgery, the patient had no evidence of recurrence or metastasis and remained orthotropic in primary gaze, with a good cosmetic result.

Conclusions and Importance

ASPS of extraocular muscles is a rare tumor occurring mainly in children and young adults, and treatment may cause significant sequelae such as orbital exenteration, radiation-induced complications, and large-angle strabismus. Complete resection of tumor including the extraocular muscle is essential for treatment, and a subsequent reconstruction using a hang-back suture technique is useful to achieve proper eye alignment as well as a good cosmetic outcome.

Soft Tissue Special Issue: Imaging of Bone and Soft Tissue Sarcomas in the Head and Neck

Bone and soft tissue sarcomas of the head and neck are a heterogenous group of tumors with overlapping features. Distinguishing between the various subtypes is challenging but necessary for appropriate diagnosis and management. The purpose of this article is to discuss the role of imaging in evaluating head and neck tumors, provide a general radiographic approach in differentiating between benign versus malignant lesions and give examples of selected subtypes of bone and soft tissue sarcomas in the head and neck with classic or pathognomonic imaging findings.

Alveolar soft part sarcoma in children and young adults: A report of 69 cases

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare mesenchymal tumor characterized by ASPL-TFE3 translocation. Apart from complete surgical resection, there is no standard management strategy.

PROCEDURE

The clinical data of 69 children and young adults less than 30 years old with ASPS diagnosed from 1980-2014 were retrospectively collected from four major institutions.

RESULTS

Median age at diagnosis was 17 years (range: 1.5-30). Forty-four (64%) were female. Median follow-up was 46 months (range: 1-409). Most common primary sites were limbs (58%) and trunk (24%). ASPL-TFE3 translocation was present in all 26 patients tested. IRS postsurgical staging was I in 19 (28%), II in 7 (10%), III in 5 (7%), and IV in 38 (55%) patients. The 5-year event-free survival (EFS) and overall survival (OS) were 38% and 72%, respectively. The 5-year EFS and OS were 80% and 87%, respectively, for the 31 patients with localized tumors (IRS-I-II-III), and 7% and 61%, respectively, for the 38 patients with metastatic tumors (IRS-IV). Of 11 IRS-IV patients who received targeted therapy upfront, two had partial response, six had stable disease, and three had progressive disease. Median time to progression for IRS-IV patients was 12 months for those treated with targeted therapy, 7 months for cytotoxic chemotherapy (N = 15), and 4 months for observation only (N = 6).

CONCLUSION

Localized ASPS has a good prognosis after gross total resection. ASPS is resistant to cytotoxic chemotherapy. Although there are no curative therapies for patients with metastatic disease, prolonged disease stabilization may be achieved with targeted therapies.

Imaging in Soft Tissue Sarcomas: Current Updates

Soft tissue sarcomas (STS) are heterogeneous malignant tumors that have nonspecific imaging features. A combination of clinical, demographic, and imaging characteristics can aid in the diagnosis. Imaging provides important information regarding the tumor extent, pretreatment planning, and surveillance of patients with STS. In this article, we illustrate the pertinent imaging characteristics of the commonly occurring STS and some uncommon sarcomas with unique imaging characteristics.

Orbital alveolar soft part sarcoma: A report of 8 cases and review of the literature

Alveolar soft part sarcoma (ASPS) is a rare soft tissue neoplasm. The incidence of orbital involvement is the highest in ASPS arising in the head and neck region. However, limited information is available regarding its clinical characteristics. The present study presents the clinical manifestations, imaging findings, pathological features, treatment strategies and prognosis records of 8 cases of orbital ASPS over the last 15 years in a single hospital, along with a review of the literature. Included were 3 male and 5 female patients, with the median age at presentation being 9.5 years. The mean average largest tumour diameter was 3.6 cm. A total of 5 patients underwent surgical excision of the tumour, with 2 undergoing orbital exenteration and 1 undergoing partial orbital exenteration. In total, 6 patients received postoperative radiotherapy and 2 received chemotherapy. Upon follow-up, 6 patients were doing well with no evidence of recurrence or metastasis. Local recurrence developed in 2 patients, of whom 1 succumbed following withdrawal from treatment. According to the present series and the cases mentioned in the literature, orbital alveolar soft part sarcoma has characteristics distinct from those of alveolar soft part sarcoma which arises in other locations. Orbital alveolar soft part sarcoma presents itself in a younger population with a shorter course of disease, smaller tumour size, improved prognosis, a marked association with the extraocular muscles and with the Ki-67 proliferation index possibly associated with prognosis of the disease.

Clinical presentation and CT/MRI findings of alveolar soft part sarcoma: a retrospective single-center analysis of 14 cases

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a relatively rare malignant tumor and early diagnosis and appropriate treatment for ASPS are essential for a good prognosis.

PURPOSE

To retrospectively review the clinical presentation and computed tomography (CT) and magnetic resonance imaging (MRI) findings of ASPS so as to improve the accuracy of imaging diagnosis.

MATERIAL AND METHODS

Fourteen patients with pathologically proven ASPS were enrolled. Their clinical and imaging findings were retrospectively reviewed.

RESULTS

The median age of the patients was 29 years (range, 13-37 years). Most tumors were located in the soft tissues of the trunk and lower limbs. The median maximal diameter of the masses was 91 mm. Thirteen masses presented with ovoid or irregular shapes. Eleven masses had less clear boundaries. Compared with the adjacent muscles, the masses were isodense or hypodense on CT, hypo-, iso-, or hyperintense on T1-weighted images, and heterogeneous hyperintense on T2-weighted images. Intense enhancement was seen after contrast agent administration, with prominent intra- or peri-tumoral feeders on CT or flow voids on MRI. By the end of the last follow-up, 13 patients had distant metastasis and three patients had local recurrence.

CONCLUSION

ASPS should be included in the differential diagnosis when a bulky, heterogeneous soft tissue mass in the trunk and the lower limbs with intense enhancement after contrast administration and prominent intra- or peri-tumoral feeders on CT or flow voids on MRI is seen, particularly in young patients.

[Alveolar soft part sarcoma in pediatric patients]

Alveolar soft part sarcoma, ASPS, is a rare malignant tumor, with preferential primary localization in limbs, usually occurring in adolescents and young adults. This sarcoma, well defined histologically and at molecular level, has an indolent course, but a high potential metastatic pulmonary and cerebral evolution, sometimes late. ASPS is characterized by an almost specific translocation t(X, 17)(p11;25) which creates a fusion protein, APSL-TFE3, acting as an aberrant transcription factor. An in-bloc resection of the primary tumor is the treatment of choice in cases of localized disease. Conventional chemotherapy is generally ineffective. The role of radiotherapy is discussed in case of micro- or macroscopical incomplete residue. It seems to reduce local recurrence, but did not influence overall survival. The 5 years survival rate in children, adolescents and young adults is close to 80% in case of localized disease but poorer in presence of metastases. Recently, systemic anti-tumoral treatments have been focused on the use of targeted therapies. Anti-angiogenic drugs and tyrosine kinase inhibitors are the most promising approaches, but require further study. Prognostic risk factors in the literature are age (>10Y), tumor size (>5cm) and presence of metastases. This article reviews the clinical manifestations, diagnosis modalities, radiographic characteristics and therapeutic strategy of this disease in the pediatric population.

Imaging features of alveolar soft-part sarcoma: a report from Children's Oncology Group Study ARST0332

OBJECTIVE

There are few studies in the literature regarding the imaging features of alveolar soft-part sarcoma (ASPS). We performed a comprehensive assessment of the imaging characteristics of this rare tumor to determine whether there are features that suggest the diagnosis.

MATERIALS AND METHODS

Twenty-two subjects with ASPS underwent pretherapy imaging as part of enrollment in Children's Oncology Group protocol ARST0332 for the treatment of nonrhabdomyosarcoma soft-tissue sarcomas: 16 patients underwent MRI; three, CT; and three, both MRI and CT. Two radiologists retrospectively reviewed the imaging studies by consensus and recorded tumor location, size, contour, internal architecture, signal characteristics, presence of flow voids, and enhancement patterns.

RESULTS

The 12 females and 10 males in the study group ranged in age from 8 to 23 years 7 months (mean, 15 years 8 months). The most common anatomic site was the lower extremity (12/22, 55%) followed by the upper extremity (4/22, 18%). The maximal tumor diameter ranged from 2.3 to 20.0 cm (median, 5.9 cm). All tumors imaged with MRI had flow voids (19/19, 100%), and 19 (19/22, 86%) had large peripheral vessels, lobulated margins, and nodular internal architecture. Unenhanced T1-weighted MRI was available for 18 tumors: 14 (14/18, 78%) appeared slightly hyperintense to muscle. Of the 16 tumors imaged with contrast material, 11 (11/16, 69%) showed intense enhancement and five (5/16, 31%), moderate enhancement. Six tumors (6/16, 38%) had a thick enhancing peripheral rim with a nonenhancing center consistent with necrosis.

CONCLUSION

The imaging features of ASPS include flow voids, large peripheral vessels, internal nodularity, and lobulated margins. Contrast administration produces intense to moderate enhancement, sometimes with a thick enhancing peripheral rim around central necrosis. Extremity tumors with these imaging features in a child or young adult should suggest the diagnosis of ASPS.

Alveolar soft part sarcoma arising from the kidney: imaging and clinical features

Alveolar soft part sarcoma (ASPS) is an extremely rare malignant soft tissue sarcoma primarily affecting young patients. It usually occurs in the lower extremities, although it can occur in soft tissue anywhere in the body. However, to our knowledge, there has been no case of primary ASPS originating from the kidney in the literature. We herein present the imaging and clinical features of an ASPS which occurred in a 16-year-old male presented as a palpable mass in the left side of the abdomen.

Malignant soft tissue tumors in children

Soft tissue masses are frequently seen in children. Although most are benign or reactive, soft tissue sarcomas (STS)-both rhabdomyosarcoma (most common) and non-rhabdo STS, do occur in the extremities. Appropriate evaluation of extremity soft tissue tumors often includes a biopsy as the clinical and imaging features may not be enough to establish a definitive diagnosis. Much needs to be done for improving the treatment of these rare but often devastating sarcomas. Given the small numbers of these cases seen at various centers, collaborative efforts should be made to further our understanding and improve the management of these challenging cases.