Histological analysis suggests an invasion-independent metastatic mechanism in alveolar soft part sarcoma

The Prognostic Relevance of MRI Characteristics in Myxofibrosarcoma Patients Treated with Neoadjuvant Radiotherapy

To improve local control, neoadjuvant radiotherapy (nRT) followed by surgery is the standard of care in myxofibrosarcoma (MFS) because of its infiltrative growth pattern. Nevertheless, local recurrence rates are high. Data on prognostic factors for poor clinical outcomes are lacking. This retrospective study thus investigates the prognostic relevance of magnetic resonance imaging (MRI) characteristics before and after nRT in 40 MFS patients, as well as their association with disease-free survival (DFS) and overall survival (OS). A vascular pedicle, defined as extra-tumoral vessels at the tumor periphery, was observed in 12 patients (30.0%) pre-nRT and remained present post-nRT in all cases. Patients with a vascular pedicle had worse DFS (HR 5.85; 95% CI 1.56-21.90; p = 0.009) and OS (HR 9.58; 95% CI 1.91-48.00; p = 0.006). An infiltrative growth pattern, referred to as a tail sign, was observed in 22 patients (55.0%) pre-nRT and in 19 patients (47.5%) post-nRT, and was associated with worse DFS post-nRT (HR 6.99; 95% CI 1.39-35.35; p = 0.019). The percentage of tumor necrosis estimated by MRI was increased post-nRT, but was not associated with survival outcomes. The presence of a tail sign or vascular pedicle on MRI could support the identification of patients at risk for poor clinical outcomes after nRT.

Sonographic imaging features of alveolar soft part sarcoma: Case series and literature review

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare tumor but potentially fatal condition. Understanding the imaging and clinical features of ASPS is of certain value for preoperative qualitative diagnosis and clinical treatment of tumors. Nevertheless, there have been only 11 documented case reports describing the sonographic features in the English literature.

METHODS

Three patients with confirmed ASPS occurring primarily in the limbs were enrolled in this study. Complete surgical excision was performed with conservative limb function. We pay particular attention to the ultrasonographic features and performed a literature review of ASPS cases.

RESULTS

With regular surveillance, one patient had no symptom recurrence and two developed lung and/or breast metastasis later. The specific sonographic findings were heterogeneous hypoechoic, well-circumscribed, and lobulated or round contours on grayscale images, abundant flow signals of intratumoral and extratumoral tubular structures on color Doppler images.

CONCLUSION SUBSECTIONS

Its low incidence rate and lack of characteristic clinical manifestations often result in misdiagnosis of ASPS. The specific sonographic findings may add useful diagnostic information.

Three-dimensional tissue model in direct contact with an on-chip vascular bed enabled by removable membranes

Three-dimensional (3D) tissue culture is a powerful tool for understanding physiological events. However, 3D tissues still have limitations in their size, culture period, and maturity, which are caused by the lack of nutrients and oxygen supply through the vasculature. Here, we propose a new method for culturing a 3D tissue-a spheroid-directly on an 'on-chip vascular bed'. The method can be applied to any 3D tissue because the vascular bed is preformed, so that angiogenic factors from the tissue are not necessary to induce vasculature. The essential component of the assay system is the removable membrane that initially separates the 3D tissue culture well and the microchannel in which a uniform vascular bed is formed, and then allows the tissue to be settled directly onto the vascular bed following its removal. This in vitro system offers a new technique for evaluating the effects of vasculature on 3D tissues.

Abnormal vascularization of soft-tissue sarcomas on conventional MRI: Diagnostic and prognostic values

PURPOSE

To assess the prevalence of abnormal vessels inside and surrounding soft-tissue sarcomas (STS) on conventional MRIs so as to evaluate their correlations with particular histotypes, histological grades, and prognosis.

METHOD

This single-center retrospective study included 157 adult patients (median age: 61) with histologically-proven non-metastatic STS. All had pre-treatment conventional contrast-enhanced MRI. Two radiologists reported: presence of abnormal flow-voids, number and distribution (peri-tumoral and/or intra-tumoral), percentage of tumor circumference it covered, maximal diameter. The radiological findings were correlated with histopathology. Associations were evaluated with Chi-2 or t-tests. Survival analysis (for metastasis-free survival (MFS) and overall survival (OS)) included log-rank tests and multivariate Cox-model.

RESULTS

Twenty-nine of 157 (18.5%) STS showed abnormal flow-voids that were peri-tumoral (9/157, 5.7%), intra-tumoral (5/157, 3.2%) or both intra- and peri-tumoral (15/157, 9.6%). Ten STS had more than 5 flow-voids, all being grade II-III, namely: 4 undifferentiated sarcomas, 2 solitary fibrous tumors, 1 alveolar soft-part sarcoma (ASPS), 2 leiomyosarcomas and 1 pleomorphic liposarcoma. The distribution of flow-voids was associated with survivals in the univariate analysis: patients with abnormal peritumoral flow-voids (APTFV) showed poorer OS and MFS (p = 0.039 and 0.014, respectively). These associations did not remain significant in multivariate analysis. Radio-pathological correlations revealed large tortuous tumoral neo-vessels with intra-vascular thrombi of tumor cells in ASPS and in one case of undifferentiated sarcoma displaying enrichment in genes involved in neo-angiogenesis at transcriptional level.

CONCLUSIONS

APTFV on conventional MRIs may be associated with a higher risk of metastatic relapse and poorer OS in STS patients.

Alveolar soft part sarcoma occurring in the penis of a 3-year-old boy: A rare case report

RATIONALE

Alveolar soft part sarcoma (ASPS) is a rare, malignant neoplasm, which mostly occurs in the upper and lower extremities. This article presents an unusual case of ASPS involving the penis of a 3-year-old boy. To our knowledge, this is the first case of ASPS in the penis of a child.

PATIENT CONCERNS

The patient complained of slight penile pain for 1 year and a soft tissue mass could be palpated in his penis.

DIAGNOSES

Imaging was performed on the penis. The pathological feature of the mass was evaluated through biopsy examination. It was found that the mass was an alveolar soft tissue sarcoma, which was then confirmed by immunohistochemistry.

INTERVENTIONS

The patient only underwent a partial penectomy because his parents wished to keep the penis. Conventional chemotherapy has been performed for 6 months after the surgery.

OUTCOMES

At 28-month follow-up the mass did not increase apparently, and no signs of metastasis were found.

LESSONS

ASPS may occur originally in the penis.

Diagnostically Challenging Epithelioid Soft Tissue Tumors

In this article, we focus on the histologic features, differential diagnosis, and potential pitfalls in the diagnosis of epithelioid sarcoma, alveolar soft part sarcoma, clear-cell sarcoma, ossifying fibromyxoid tumor, and malignant extrarenal rhabdoid tumor. Numerous other soft tissue tumors also may have epithelioid variants or epithelioid features. Examples include epithelioid angiosarcoma, epithelioid malignant peripheral nerve sheath tumor, epithelioid gastrointestinal stromal tumor, and perivascular epithelioid cell tumor, among others.

[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.