Alveolar soft part sarcoma 'revisited': clinicopathological review of 47 cases from a tertiary cancer referral centre, including immunohistochemical expression of TFE3 in 22 cases and 21 other tumours. Pathology. 2012;44:11-17. [PMID: 22173238 DOI: 10.1097/PAT.0b013e32834d7ba4]

The Relevance of the Virchow Node and Virchow Triad in Renal Cancer Diagnosis

Background: The purpose of this article is to overview the clinical significance of left supraclavicular adenopathy and review the etiology of inferior vena cava (IVC) thrombosis, starting from a presentation of a rare case of renal cell carcinoma (RCCs) with Xp11.2 translocation involving TFE3 gene fusion. This article also aims to review the literature to understand the characteristics of this rare type of renal tumor. Renal cell carcinoma (RCC) associated with Xp11.2 translocation/gene fusion TFE3 is a rare subtype of kidney cancer that was classified in 2016 as belonging to the family of renal carcinomas with MiT gene translocation (microphthalmia-associated transcription factor). The prognosis for these kidney cancers is poorer compared to other types. Methods: We present a case of a 66-year-old man with Virchow-Troisier adenopathy during physical examination, which raises the suspicion of infra-diaphragmatic tumor. The echocardiography highlighted a heterogeneous mass in the right cardiac cavities, and the abdominal ultrasound exam revealed a solid mass at the upper pole of the left kidney. Results: Following computed tomography, magnetic resonance imaging, PET-CT, and histopathological and immunohistochemical examinations, the patient was diagnosed with renal carcinoma with Xp11.2 translocation and TFE3 gene fusion. Conclusions: IVC thrombosis is often associated with neoplastic disease due to the procoagulant state of these patients, the most common malignancies related to IVC thrombosis being represented by RCCs (38%), genitourinary cancers (25%), bronchus and lung cancers, retroperitoneal leiomyosarcoma, and adrenal cortical carcinoma. Imaging methods play a crucial role in differential diagnosis, allowing for the localization of the primary tumor and assessment of its characteristics.

Efficacy and safety of nivolumab monotherapy in patients with unresectable clear cell sarcoma and alveolar soft part sarcoma (OSCAR Trial/NCCH1510)

BACKGROUND

Clear cell sarcoma (CCS) and alveolar soft part sarcoma (ASPS) are rare, and standard systemic therapy is not established except for sunitinib in ASPS. It is known that CCS and ASPS have a common biological feature of melanoma and Xp11.2/TFE3 translocation renal cell carcinoma, and immune-checkpoint inhibitors (ICIs) are effective in these tumors. The authors conducted a phase 2 trial to evaluate the efficacy and safety of nivolumab for CCS and ASPS.

METHODS

The number of patients expected to be enrolled was 15-25 and was determined based on the Bayesian design. The primary end point was the confirmed objective response rate (ORR) according to the central review and the secondary end points included ORR, progression-free survival (PFS), overall survival (OS), and safety.

RESULTS

A total of 26 patients (CCS, 12; ASPS, 14) were enrolled. Efficacy and safety were analyzed on 25 and 26 patients, respectively. The minimum number of responses required for a positive conclusion regarding the efficacy was four. However, only one patient (4.0%) with ASPS had a partial response. Complete response, stable disease, progression disease, and not evaluable were 0%, 60%, 32%, and 4.0%, respectively. Adverse events of grade 3 or 4 occurred in 57.7% (15 of 26). The median PFS was 4.9 months (95% confidence interval [CI], 3.7-8.6 months) and the median OS was 15.8 months (95% CI, 8.2-not reached).

CONCLUSIONS

The primary end point of the ORR was not met for CCS and ASPS on the central review. Further studies are needed to evaluate ICIs in patients with ASPS.

Evaluation of TRIM63 RNA in situ hybridization (RNA-ISH) as a potential biomarker for alveolar soft-part sarcoma (ASPS)

Alveolar soft-part sarcoma (ASPS) is a rare soft tissue tumor with a broad morphologic differential diagnosis. While histology and immunohistochemistry can be suggestive, diagnosis often requires exclusion of other entities followed by confirmatory molecular analysis for its characteristic ASPSCR1-TFE3 fusion. Current stain-based biomarkers (such as immunohistochemistry for cathepsin K and TFE3) show relatively high sensitivity but may lack specificity, often showing staining in multiple other entities under diagnostic consideration. Given the discovery of RNA in situ hybridization (RNA-ISH) for TRIM63 as a sensitive and specific marker of MiTF-family aberration renal cell carcinomas, we sought to evaluate its utility in the workup of ASPS. TRIM63 RNA-ISH demonstrated high levels (H-score greater than 200) of expression in 19/20 (95%) cases of ASPS (average H-score 330) and was weak or negative in cases of paraganglioma, clear cell sarcoma, rhabdomyosarcoma, malignant epithelioid hemangioendothelioma, as well as hepatocellular and adrenal cortical carcinomas. Staining was also identified in tumors with known subsets characterized by TFE3 alterations such as perivascular epithelioid cell neoplasm (PEComa, average H-score 228), while tumors known to exhibit overexpression of TFE3 protein without cytogenetic alterations, such as melanoma and granular cell tumor, generally showed less TRIM63 ISH staining (average H-scores 147 and 96, respectively). Quantitative assessment of TRIM63 staining by RNA-ISH is potentially a helpful biomarker for tumors with molecular TFE3 alterations such as ASPS.

Pitfalls in soft tissue cytopathology

Fine needle aspiration biopsy (FNAB) is a diagnostic modality for the evaluation of suspicious soft tissue masses. Despite its reasonable sensitivity, specificity and positive predictive value in differentiating benign from malignant neoplasms, the exact subtyping of the primary soft tissue tumours can be challenging. Certain tumours constitute "pitfalls" and add to the diagnostic challenge. This review provides a detailed account of the diagnostic challenges in soft tissue cytopathology, including pitfalls and, more importantly, the ways to overcome these challenges by integrating clinical details, key cytomorphological features and judicious application of ancillary techniques.

Targeting epigenetic aberrations of sarcoma in CRISPR era

Sarcomas are rare malignancies that exhibit diverse biological, genetic, morphological, and clinical characteristics. Genetic alterations, such as gene fusions, mutations in transcriptional machinery components, histones, and DNA methylation regulatory molecules, play an essential role in sarcomagenesis. These mutations induce and/or cooperate with specific epigenetic aberrations required for the growth and maintenance of sarcomas. Appropriate mouse models have been developed to clarify the significance of genetic and epigenetic interactions in sarcomas. Studies using the mouse models for human sarcomas have demonstrated major advances in our understanding the developmental processes as well as tumor microenvironment of sarcomas. Recent technological progresses in epigenome editing will not only improve the studies using animal models but also provide a direct clue for epigenetic therapies. In this manuscript, we review important epigenetic aberrations in sarcomas and their representative mouse models, current methods of epigenetic editing using CRISPR/dCas9 systems, and potential applications in sarcoma studies and therapeutics.

Primary Intracranial Alveolar Soft Part Sarcoma: A Report of 3 Cases

Alveolar soft part sarcoma (ASPS) commonly involves extremities and head and neck regions. Primary intracranial ASPS is rare. We report a series of 3 primary intracranial ASPS. These were not suspected clinically and histopathology with immunohistochemistry proved to be diagnostic in all 3 tumors.

Lingual Alveolar Soft Part Sarcoma in a 78-Year-Old Woman: A Case Report and Comprehensive Review of the Literature from 1952 to 2022

BACKGROUND

Alveolar soft part sarcoma (ASPS) is a rare translocation-related soft tissue sarcoma, occurring mainly in the limbs and trunk in young adults and adolescents. ASPS is rarely seen in the head and neck and one fourth of those cases described are tongue primary. Given its nonspecific symptoms, clinical findings, and rarity in this location, lingual ASPS (L-ASPS) has been reported to be commonly misdiagnosed as various benign tumors, leading to adverse outcomes.

METHODS

We report a case of L-ASPS occurring in the oldest (78 years) female patient published to date and comprehensively review the literature from 1952 to 2022.

RESULTS

She presented with a slow-growing (2-year duration) tongue mass, measuring 3.5 cm on palpation. Intraoperative frozen section could not render the definitive diagnosis. The pathological findings of the tumor were characteristic of ASPS with eosinophilic polygonal cells in an organoid/nested pattern, rich sinusoidal capillaries, and TFE3 immunoreactivity, except for the strong diffuse aberrant cytoplasmic CD68 immunoexpression and absence of intracytoplasmic crystalline inclusions on PAS with diastase. After TFE3 gene rearrangement had been identified with fluorescent in-situ hybridization, reflex testing confirmed a rearrangement of TFE3 gene with the known fusion partner ASPSCR1.

CONCLUSIONS

ASPS should be included in the differential diagnoses in cases of any slow-growing lingual masses (especially vascular ones) with non-specific clinical pictures, regardless of the patient's age.

Diagnosis of Fusion-Associated Sarcomas by Exon Expression Imbalance and Gene Expression

Sarcomas are a diverse group of tumors, with >70 subtypes in the current World Health Organization classification, each with distinct biological behavior requiring specific clinical management. A significant portion of sarcomas are molecularly defined by expression of a driver fusion gene; identification of such fusions is the basis of molecular diagnostics in sarcomas, which is of increasing complexity due to the ongoing discovery of new gene fusions. Recently, a multiplex NanoString platform-based assay was developed and clinically implemented, with fusion junction-spanning probes that detect the majority of sarcoma fusion types, with high sensitivity and specificity, and with lower cost and shorter turnaround time than those of targeted next-generation sequencing-based alternatives. Despite the effectiveness of this assay, there are several entities for which fusion-junction probes are not suitable due to multiple possible gene partners or excessive variability at the exon junctions. Here, the development and evaluation of a companion assay are described that uses NanoString-based gene expression analysis to detect aberrant 3'/5' exon expression imbalance and/or total gene overexpression as a surrogate marker for fusion gene rearrangement. This assay evaluates exon imbalance in 23 genes involved in over 25 mesenchymal tumor types and five genes specific to sarcomas with CIC rearrangements. Based on evaluation of 115 retrospectively and 91 prospectively collected cases, an assay sensitivity of 92.8% and specificity of 93.5% are demonstrated.

Molecular testing of soft tissue tumors

BACKGROUND

The diagnosis of soft tissue tumors is challenging, especially when the evaluable material procured is limited. As a result, diagnostic ancillary testing is frequently needed. Moreover, there is a trend in soft tissue pathology toward increasing use of molecular results for tumor classification and prognostication. Hence, diagnosing newer tumor entities such as CIC-rearranged sarcoma explicitly requires molecular testing. Molecular testing can be accomplished by in situ hybridization, polymerase chain reaction, as well as next generation sequencing, and more recently such testing can even be accomplished leveraging an immunohistochemical proxy.

CONCLUSION

This review evaluates the role of different molecular tests in characterizing soft tissue tumors belonging to various cytomorphologic categories that have been sampled by small biopsy and cytologic techniques.

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.

Chameleon TFE3-translocation RCC and How Gene Partners Can Change Morphology: Accurate Diagnosis Using Contemporary Modalities

Translocation renal cell carcinoma (tRCC) with TFE3 gene rearrangements has been born as a distinct entity 20 years ago. These relatively rare tumors were notable among other RCC subtypes because of their disproportionally high incidence among children and young adults. Initial reports were focused on describing unifying morphologic criteria and typical clinical presentation. Follow-up studies of ancillary immunohistochemical and hybridization techniques provided additional diagnostic tools allowing recognition of tRCC tumors in practice. However, a growing body of literature also expanded the clinicomorphologic spectrum of tRCCs, to include a significant morphologic overlap with other RCC variants thus blurring the diagnostic clarity of this entity. More recent molecular studies utilizing next-generation sequencing technology accelerated recognition of numerous novel gene partners fusing at different breakpoints with the TFE3 gene. Accumulating data indicates that morphologic and clinical heterogeneity of tRCC could be explained by fusion subtypes, and knowledge of TFE3 partnering genes may be important in predicting tumor behavior. Herein we provided a comprehensive analysis of ∼400 tRCC cases with known TFE3 fusion partners, estimated their relative incidence and summarized clinicomorphologic features associated with most common fusion subtypes. Our data was based on an extensive literature review and had a special focus on comparing immunohistochemistry, fluorescent in situ hybridization and contemporary molecular studies for the accurate diagnosis of tRCC.

Primary Alveolar Soft Part Sarcoma of Cheek: Report of a Case and Review of the Literature

Alveolar soft part sarcoma (ASPS) is a rare soft tissue sarcoma characterized by an alveolar or organoid arrangement of polygonal tumour cells separated by fibrovascular septa. A specific fusion gene [ASPS critical region 1 (ASPSCR1)-TFE3] was detected in ASPS. Despite being a slow-growing tumour without pain and dysfunction, ASPS is characterized by early metastasis, which leads to poor prognosis. Herein, we report a rare case of primary ASPS of the cheek harbouring ASPSCR1 (exon 7)-TFE3 (exon 5) fusion gene in a 21 year-old woman. This tumour was a well-circumscribed, smooth, round mass that was clinically suspected as a benign tumour. However, histologically, it was observed that the polygonal tumour cells were arranged in solid and alveolar growth patterns. Post-operative examination of the whole body excluded the possibility of metastasis at other sites. Thus, careful immunohistochemical and genetic analyses, as well as whole-body examination, demonstrated that the tumour was a primary ASPS of the cheek.

YAP1-TFE3-fused hemangioendothelioma: a multi-institutional clinicopathologic study of 24 genetically-confirmed cases

YAP1-TFE3-fused hemangioendothelioma is an extremely rare malignant vascular tumor. We present the largest multi-institutional clinicopathologic study of YAP1-TFE3-fused hemangioendothelioma to date. The 24 cases of YAP1-TFE3-fused hemangioendothelioma showed a female predominance (17 female, 7 male) across a wide age range (20-78 years old, median 44). Tumors were most commonly located in soft tissue (50%), followed by bone (29%), lung (13%), and liver (8%), ranging from 3 to 115 mm in size (median 40 mm). About two-thirds presented with multifocal disease, including 7 cases with distant organ metastasis. Histopathologically, we describe three dominant architectural patterns: solid sheets of coalescing nests, pseudoalveolar and (pseudo)vasoformative pattern, and discohesive strands and clusters of cells set in a myxoid to myxohyaline stroma. These patterns were present in variable proportions across different tumors and often coexisted within the same tumor. The dominant cytomorphology (88%) was large epithelioid cells with abundant, glassy eosinophilic to vacuolated cytoplasm, prominent nucleoli and well-demarcated cell borders. Multinucleated or binucleated cells, prominent admixed erythrocytic and lymphocytic infiltrates, and intratumoral fat were frequently present. Immunohistochemically, ERG, CD31, and TFE3 were consistently expressed, while expression of CD34 (83%) and cytokeratin AE1/AE3 (20%) was variable. CAMTA1 was negative in all but one case. All cases were confirmed by molecular testing to harbor YAP1-TFE3 gene fusions: majority with YAP1 exon 1 fused to TFE3 exon 4 (88%), or less commonly, TFE3 exon 6 (12%). Most patients (88%) were treated with primary surgical resection. Over a follow-up period of 4-360 months (median 36 months) in 17 cases, 35% of patients remained alive without disease, and 47% survived many years with stable, albeit multifocal and/or metastatic disease. Five-year progression-free survival probability was 88%. We propose categorizing YAP1-TFE3-fused hemangioendothelioma as a distinct disease entity given its unique clinical and histopathologic characteristics in comparison to conventional epithelioid hemangioendothelioma.

Role of pre-operative percutaneous embolization in orbital alveolar soft part sarcoma - An experience from a tertiary eye-care center

Purpose:

To describe the clinic-radiological, pathological profile, and management outcomes of primary alveolar soft-part sarcoma (ASPS) of the orbit.

Methods:

A retrospective analysis of all histopathologically proven cases of orbital ASPS that presented between May 2016 and September 2019 was done. Data collected included demographics, clinical features, imaging characteristics, metastatic workup, management, and follow-up.

Results:

Five patients, of which four were males, presented to us during the study period. The mean age of presentation was 12.6 years (range 3–22 years). The most common presenting features were abaxial proptosis (n = 4) and diminished vision (n = 4). Imaging showed a well-defined orbital mass in all patients with internal flow voids in three. Preoperative percutaneous embolization with cyanoacrylate glue was done in these three patients owing to high vascularity. Four patients underwent complete tumor excision. One patient underwent exenteration. Histopathology showed polygonal tumor cells arranged in a pseudo-alveolar pattern and Periodic Acid-Schiff (PAS) positive crystals in the cytoplasm in all patients. One patient had systemic metastasis at presentation and developed a local recurrence after 3 months. No recurrence or metastasis was noted in the remaining four patients at a mean final follow-up of 11.2 months (range 5–15 months).

Conclusion:

ASPS is a rare orbital neoplasm that poses a diagnostic and therapeutic challenge. Imaging might show a soft-tissue tumor with high vascularity. Multidisciplinary management with interventional radiologists for preoperative embolization of vascular lesions helps minimize intraoperative bleeding and aids in complete tumor resection. A localized orbital disease carries a better prognosis.

Mesenchymal Tumors of the Mediastinum: An Update on Diagnostic Approach

Mesenchymal tumors of the mediastinum are a heterogenous group of rare tumors with divergent lineages. Mediastinal mesenchymal tumors are diagnostically challenging due to their diversity and morphologic overlap with nonmesenchymal lesions arising in the mediastinum. Accurate histologic diagnosis is critical for appropriate patient management and prognostication. Many mediastinal mesenchymal tumors affect distinct age groups or occur at specific mediastinal compartments. Neurogenic tumors, liposarcoma, solitary fibrous tumor, and synovial sarcoma are common mesenchymal tumors in the mediastinum. Herein, we provide an update on the diagnostic approach to mediastinal mesenchymal tumors and a review of the histologic features and differential diagnosis of common benign and malignant mesenchymal tumors of the mediastinum.

A case of multiple synchronously diagnosed brain metastases from alveolar soft part sarcoma without concurrent lung involvement

Background:

Alveolar soft part sarcoma (ASPS) is a rare soft-tissue sarcoma with a propensity for early hematogenous dissemination to the lungs and frequent brain metastasis. The development of lung metastasis almost invariably precedes intracranial involvement. There are no previously reported cases in which a patient was synchronously diagnosed with ASPS and multiple brain metastasis without lung involvement.

Case Description:

A 29-year-old gentleman was found to have three intracranial lesions following the onset of generalized seizures. Staging studies identified a soft-tissue mass in the left thigh and an adjacent femoral lesion. Biopsy of the soft-tissue mass was consistent with ASPS. The patient then underwent neoadjuvant stereotactic radiotherapy to all three brain lesions, followed by en bloc resection of the dominant lesion. The patient was then started on a programmed death-ligand 1 (PD-L1) inhibitor. Subsequent surgical resection of the primary lesion and femur metastasis demonstrates a histopathologic complete response of the bony metastasis and partial response of the primary lesion. At present, the patient has received 14 cycles of atezolizumab without recurrence of the primary or bony lesions and the irradiated intracranial disease has remained stable without recurrence of the resected dominant lesion.

Conclusion:

While intracranial involvement is relatively common in ASPS, a case with multiple, synchronously diagnosed brain metastasis without concurrent lung metastasis has not been described. The presented case discusses the safety and efficacy of aggressive management of intracranial disease in the setting of atezolizumab. Prospective evaluation of the efficacy of checkpoint inhibitors and the prognostic value of PD-L1 expression in ASPS with brain metastasis are necessary.

Revisiting cytomorphology, including unusual features and clinical scenarios of 8 cases of alveolar soft part sarcoma with TFE3 immunohistochemical staining in 7 cases

OBJECTIVES

To present a comprehensive analysis of cytomorphological features, including clinical scenarios, for 8 cases (4 males, 4 females, aged 17-39 years, average = 28.5) of, retrospectively diagnosed alveolar soft part sarcoma (ASPS), with TFE3 immunostaining in 7 cases.

METHODS

Conventional Papanicolaou and May Grunwald-Giemsa (MGG) stained smears and corresponding tissue sections were critically reviewed. Fine needle aspiration cytology was performed for primary diagnosis in 6 cases and for metastatic lesions in 2 cases. TFE3 and other immunohistochemical stains were tested using polymer detection technique.

RESULTS

Tumour sites were thigh (n = 6), shoulder (1) and neck (1). Tumour size (n = 6) varied from 5 to 14.5 cm (average = 7.2). Seven out of 8 cases were correctly diagnosed on cytosmears. The smears were mostly hypercellular (5), composed of cohesive clusters (8), including cell balls and pseudopapillae (3) and singly scattered cells (8). Tumour cells were round to oval, containing central to eccentric nuclei (8), abundant granular (8) to finely vacuolated (7) cytoplasm that was ill- to well-defined, intracytoplasmic rod-like or needle-shaped crystals (3) and prominent nucleoli (8), Additionally, there were binucleated cells (7), multinucleation (2), intracytoplasmic inclusions (3), intranuclear inclusions (2), intercellular stroma (5) and bare nuclei (8). Immunohistochemically, 7/8 tumours were positive for TFE3.

CONCLUSIONS

This constitutes the largest series describing cytomorphological spectrum of ASPS with TFE3 immunostaining results. Frequently observed features and rod-like/needle-shaped crystals on MGG smears, can help to differentiate ASPS from its mimics. TFE3 immunostaining aids in substantiating diagnoses, in an appropriate clinicoradiological context.

Retroperitoneal Sarcomas: An Update on the Diagnostic Pathology Approach

Retroperitoneal sarcomas are a heterogenous group of rare tumors arising in the retroperitoneum. Retroperitoneal sarcomas comprise approximately 10% of all soft tissue sarcomas. Though any soft tissue sarcoma histologic types may arise in the retroperitoneal space, liposarcoma (especially well-differentiated and dedifferentiated types) and leiomyosarcoma do so most commonly. Retroperitoneal sarcomas are diagnostically challenging, owing to their diversity and morphological overlap with other tumors arising in the retroperitoneum. An accurate diagnosis is necessary for correct management and prognostication. Herein, we provide an update on the diagnostic approach to retroperitoneal sarcomas and review their key histologic findings and differential diagnoses.

Primary Thyroid Gland Alveolar Soft Part Sarcoma

Alveolar soft part sarcoma (ASPS) is a rare soft tissue tumor of unknown histogenesis generally characterized by the der(17)t(X;17)(p11.2;q25) translocation which results in the ASPSCR1-TFE3 gene fusion. Primary ASPS of the thyroid gland has not yet been reported. During oncology follow-up for breast cancer, a pulmonary nodule and thyroid gland mass were identified in a 71-year-old Korean male. Thyroid ultrasound showed a 5.7 cm left thyroid gland mass. After several fine needle aspirations, a thyroid gland lobectomy was performed after documenting only non-caseating granulomatous inflammation in a biopsy of the lung nodule. A 7.6 cm bulging nodular thyroid gland mass was identified, showing significant destructive invasion. Alveolar nests of large polygonal, eosinophilic, granular neoplastic cells were separated by vascularized stroma. Colloid was absent. Tumor necrosis and increased mitoses were identified. The neoplastic cells were positive with TFE3 and CD68, but negative with pancytokeratin, thyroglobulin, TTF-1, napsin-A, calcitonin, PAX8, CAIX, S100 protein, HMB45, SMA, and desmin. FISH confirmed a TFE3 gene rearrangement. The differential includes several primary thyroid gland epithelial neoplasms, paraganglioma, PEComa, melanoma, crystal storage disease, and metastatic carcinomas, especially Xp11 translocation renal cell carcinoma. The patient has refused additional therapy, but is alive without tumor identified (primary or metastatic).

Alveolar soft-part sarcoma of the oral cavity: A review of literature

An alveolar soft-part sarcoma is a malignant neoplasm primarily affecting the soft tissues of head and neck. The aim of the present review is to systematically present the demographic and clinico-pathological data of articles published in the English medical literature. A comprehensive search of the databases (PubMed, Medline, SCOPUS, Web of Science, and Google Scholar) along with cross references to the published articles on alveolar soft-part sarcoma for eligible studies/case reports published since 1957 till date was done to retrieve the data. A total of 74 cases were identified and analyzed from 42 papers published in the English medical literature. All the clinical, radiographic, and prognostic features were analyzed and presented along with the treatment strategies. Alveolar soft-part sarcoma is a rare and aggressive malignancy of uncertain histologic origin with a propensity for vascular invasion and distant metastasis. This neoplasm requires careful clinical, radiographic, and histopathologic evaluation to reach to the correct diagnosis.

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.

Alveolar Soft Part Sarcoma of the Female Genital Tract: A Morphologic, Immunohistochemical, and Molecular Cytogenetic Study of 10 Cases With Emphasis on its Distinction From Morphologic Mimics

Alveolar soft part sarcoma (ASPS) is a morphologically distinctive neoplasm of unknown differentiation that bears a characteristic gene fusion involving ASPSCR1 and TFE3. ASPS can occur in the female genital tract, but is rare. Eleven cases with an initial diagnosis of ASPS at female genital tract sites were evaluated for their morphologic features and immunoprofile using a panel of antibodies (TFE3, HMB45, melan-A, smooth muscle actin, desmin, and h-Caldesmon). In addition, the presence of TFE3 rearrangement and subsequent ASPSCR1-TFE3 fusion were determined by fluorescence in situ hybridization. Ten tumors retained their classification as ASPS based on their morphologic appearance, immunohistochemical profile, and demonstration of ASPSCR1-TFE3 fusion. The remaining case was reclassified as conventional-type PEComa due to its pattern of HMB45, melan-A, and desmin positivity as well as absence of TFE3 rearrangement. Sites of the 10 ASPS were uterine corpus (3), cervix (2), uterus not further specified (2), vagina (2), and vulva (1). The age of the patients ranged from 15 to 68 years (mean 34 y, median 32 y). The tumors demonstrated a spectrum of morphologic features, but all had a consistent immunophenotype of strong TFE3 nuclear expression and lack of muscle (smooth muscle actin, desmin, h-Caldesmon) and melanocytic (melan-A, HMB45) markers, except focal positivity for HMB45 in 1. Follow-up was available for 4 patients ranging from 1 to 35 months (mean 15 mo, median 25 mo) and they were alive and had no evidence of recurrence or metastasis at last follow-up. Distinguishing ASPS from its morphologic mimics, particularly PEComa, is important due to increasingly efficacious targeted agents such as MET-selective and VEGF signaling inhibitors in the former and mTOR inhibition therapy in the latter.

Frequent expression of human leukocyte antigen class I and the status of intratumoral immune cells in alveolar soft part sarcoma

The prognosis of alveolar soft part sarcoma is poor, despite the slow growth of the tumor. A number of cases with spontaneous regression of this rare tumor have been reported. Although the mechanisms underlying spontaneous regression remain uncertain, local immune reaction may be a possible contributing factor. Immunohistochemical expression of human leukocyte antigen (HLA) class I, cluster of differentiation (CD) 3, CD4, CD8, CD20, CD45, CD56, CD68, CD138 and CD163 were assessed in a series of 10 alveolar soft part sarcomas, and the expression profiles were associated with patients' clinicopathological parameters. Expression of HLA class I was observed in almost all the tumor cells of all cases. CD8(+) cells were identified in all tumors with varying densities. Moderate infiltration of CD8(+) cells was detected in three patients; one of these patients survived with long-term tumor remission. Infiltration of CD10(+), CD20(+), CD56(+) or CD138(+) cells was not revealed in all tumors. Moderate-diffuse infiltration of CD163(+) cells was observed in all tumors. To the best of our knowledge, the present study represents the first report of intratumoral immune cells in alveolar soft part sarcoma. Frequent expression of HLA class I in tumor cells was observed. CD8(+) cells were identified at various densities and CD163(+) cells were observed in alveolar soft part sarcoma. Moderate infiltration of CD8(+) cells in patients with a good prognosis may indicate the antitumor effects of immune cells in alveolar soft part sarcoma.

Indian data on bone and soft tissue sarcomas: A summary of published study results

Bone sarcomas are rare tumors, approximating 0.2% of all cancers, with osteosarcoma (OGS), chondrosarcoma, and Ewing sarcoma being the most common cancers in this subset. The formation of disease management groups/clinics focused on sarcomas has resulted in better understanding and management of these uncommon tumors. Multiple large-scale retrospective data from Tata Memorial Hospital (TMH) and All India Institute of Medical Sciences have reported outcomes comparable to Western data in the field of OGS and Ewing sarcoma, with interesting prognostic factors identified for further evaluation. Soft tissue sarcomas are a rare heterogeneous group of tumors, more than 50 different tumor entities. The common subtypes identified in India include Ewing sarcoma and synovial sarcoma. Valuable work regarding brachytherapy has been done by radiation oncologists from the TMH, especially in pediatric patients.

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 of lung: report of a unique case with emphasis on diagnostic utility of molecular genetic analysis for TFE3 gene rearrangement and immunohistochemistry for TFE3 antigen expression

Alveolar soft part sarcoma (ASPS) is a rare, malignant mesenchymal tumor of distinctive clinical, morphologic, ultrastructural, and cytogenetical characteristics. It typically arises in the extremities of adolescents and young adults, but has also been documented in a number of unusual sites, thus causing diagnostic confusions both clinically and morphologically. The molecular signature of ASPS is a specific der(17)t(X;17)(p11.2;q25) translocation, which results in the fusion of TFE3 transcription factor gene at Xp11.2 with ASPL at 17q25. Recent studies have shown that the ASPL-TFE3 fusion transcript can be identified by reverse-transcriptase polymerase chain reaction analysis and TFE3 gene rearragement can be detected using a dual-color, break apart fluorescence in situ hybridization assay in paraffin-embedded tissue, and the resultant fusion protein can be detected immunohistochemically with antibody directed to the carboxy terminal portion of TFE3. Herein, we report a unique case of ASPS presenting as an asymptomatic mass in the lung of a 48 year-old woman without evidence of a primary soft tissue tumor elsewhere at the time of initial diagnosis. To the best of our knowledge, this is the third report of such cases appearing in the English language literature to date. We emphasize the differential diagnoses engendered by ASPS including a series of tumors involving the lung that have nested and alveolar growth patterns, and both clear and eosinophilic cytoplasm, and demonstrate the utility of molecular genetic analysis for TFE3 rearrangement and immunohistochemistry for TFE3 antigen expression for arriving at accurate diagnosis.

Molecular diagnostics in soft tissue sarcomas and gastrointestinal stromal tumors

Soft tissue sarcomas are rare malignant heterogenous tumors of mesenchymal origin with over fifty subtypes. The use of hematoxylin and eosin stained sections (and immunohistochemistry) in the morphologic assessment of these tumors has been the bane of clinical diagnosis until recently. The last decade has witnessed considerable progress in the understanding and application of molecular techniques in refining the current understanding of soft tissue sarcomas and gastrointestinal stromal tumors beyond the limits of traditional approaches. Indeed, the identification of reciprocal chromosomal translocations and fusion genes in some subsets of sarcomas with potential implications in the pathogenesis, diagnosis and treatment has been revolutionary. The era of molecular targeted therapy presents a platform that continues to drive biomarker discovery and personalized medicine in soft tissue sarcomas and gastrointestinal stromal tumors. In this review, we highlight how the different molecular techniques have enhanced the diagnosis of these tumors with prognostic and therapeutic implications.

Needle biopsy of mesenchymal lesions of the head and neck: Evolving concepts and new strategies for diagnosis

Sarcomas are a rare and heterogeneous group of neoplasms that can be a significant diagnostic challenge in routine practice. Recent advances in the understanding of molecular mechanisms underlying oncogenesis have led to an array of novel diagnostic tools. Here we review several sarcomas of the head and neck region, focusing on neoplasms with new molecular findings and highlighting novel diagnostic tools.

Use of immunohistochemistry in the diagnosis of miscellaneous and metastatic tumors of the uterine corpus and cervix

Uncommon tumors in the uterus present diagnostic challenges. In some cases, the tumor subtype is usually seen outside the gynecologic tract and the possibility of a uterine primary is not considered. In other cases, histologic overlap with more common uterine tumors leads to potential misdiagnosis. Finally, metastatic carcinoma may involve the uterus and cervix. Rarely, symptoms related to the uterine metastasis may precede diagnosis of an extrauterine primary. Without the proper clinical context, the possibility of a missed diagnosis is increased. One must first be aware of these possibilities, but immunoperoxidase studies are often necessary to confirm the diagnosis. In this review, unusual and metastatic tumors involving the uterine corpus and cervix and immunoperoxidase studies used to diagnosis such tumors are discussed.

Paediatric and adolescent alveolar soft part sarcoma: A joint series from European cooperative groups

BACKGROUND

Alveolar soft part sarcomas (ASPS) are generally chemo- and radio-resistant mesenchymal tumours, with no standardized treatment guidelines. We describe the clinical behaviour of paediatric ASPS and compare these features to previously reported adult series.

PATIENTS AND METHODS

The clinical data of 51 children and adolescents with ASPS, prospectively enrolled in or treated according to seven European Paediatric trials were analysed.

RESULTS

Median age was 13 years [range: 2-21]. Primary sites included mostly limbs (63%). IRS post-surgical staging was: IRS-I (complete resection) 35%, II (microscopic residual disease) 20%, III (gross residual disease) 18% and IV (metastases) 27%. Only 3 of the 18 evaluable patients (17%) obtained a response to conventional chemotherapy. After a median follow-up of 126 months (range: 9-240), 14/18 patients with IRS-I tumour, 10/10 IRS-II, 7/9 IRS-III and 2/14 IRS-IV were alive in remission. Sunitinib treatment achieved two very good partial responses in four patients. Ten-year overall survival (OS) and event free survival (EFS) was 78.0 ± 7% and 62.8 ± 7% respectively. Stage IV, size >5 cm and T2 tumours had a poorer outcome, but only IRS staging was an independent prognostic factor.

CONCLUSIONS

ASPS is a very rare tumour frequently arising in adolescents and in the extremities, and chemo resistant. Local surgical control is critical. ASPS is a poorly chemo sensitive tumour. For IRS-III/IV tumours, delayed radical local therapies including surgery are essential. Metastatic patients had a poor prognosis but targeted therapies showed promising results.

A new clinical manifestation for cheek alveolar soft-part sarcoma: a case report and review of the literature

Alveolar soft part sarcoma (ASPS) is a rare, histologically distinct, soft tissue malignancy with nonspecific clinical features usually described as a nonulcerated, painless, expanding mass. It has a pseudoalveolar appearance with clustered polygonal cells lacking central cohesion. It accounts for approximately 0.5 to 1% of all soft tissue sarcomas. It has a strong predilection for adolescents and young adults 15 to 35 years old, with a female predominance. In general, ASPS grows slowly, with a predilection for the trunk and extremities and rarely in the head and neck region. A literature review found only 11 cases of cheek ASPS that have been reported since 1952. This report describes the case of an unusually rapidly growing mass in the cheek of a 36-year-old woman. The superficial location of the mass led to early detection and treatment.

The Utility of Immunohistochemistry for Providing Genetic Information on Tumors

With advances in immunohistochemical technology and growing knowledge of the molecular genetics of tumors, immunohistochemistry is playing an increasingly important role in providing genetic information for tumors. Specific chromosomal translocations can be demonstrated through detection of the protein product of one of the genes involved in gene fusion (such as BCL2, cyclin D, and ALK). Some mutations can be detected by (1) aberrant localization of the protein product (such as β-catenin and nucleophosmin), (2) abnormal accumulation of the protein product as a result of stabilization of the protein (such as p53), and (3) mutation-specific antibodies directed against the mutant protein (such as isocitrate dehydrogenase gene R132H mutation, epidermal growth factor receptor gene L858R and exon 19 deletion mutations, and BRAF gene V600E mutation). Gene deletion or loss of function can be demonstrated by the loss of immunostaining for the protein product (such as mismatch repair proteins in microsatellite-unstable tumors, E-cadherin in lobular carcinoma of the breast, and INI1 in rhabdoid tumors, atypical teratoid/rhabdoid tumors, and epithelioid sarcomas). Gene amplification can be demonstrated by overexpression of the protein product (such as HER2 in breast and gastric cancers, and MDM2 or CDK4 in well-differentiated/dedifferentiated liposarcomas). Viruses associated with tumors can be demonstrated directly (such as Epstein-Barr virus latent membrane protein-1 in Hodgkin lymphomas, human herpesvirus 8 in Kaposi sarcomas, and Merkel cell polyomavirus in Merkel cell carcinomas) or by a surrogate marker (such as p16 in human papillomavirus infection). In this review, examples are given to illustrate the principles and pitfalls of these applications.

Alveolar soft part sarcoma: unusual etiology of mediastinal mass in an adolescent

Alveolar soft part sarcoma (ASPS) is a rare malignancy that usually arises in an extremity. Mediastinal involvement is uncommon, with only two reports of primary mediastinal disease and two reports of metastatic mediastinal disease in the literature, all referencing adult patients. To our knowledge, ours is the first report of ASPS presenting with a mediastinal mass in adolescence. Although ASPS is not generally included in the differential for adolescent mediastinal masses, it should be considered when clinical presentation and imaging appearance are characteristic.

Oral alveolar soft part sarcoma in childhood and adolescence: report of two cases and review of literature

Alveolar soft part sarcoma (ASPS) constitutes a rare soft tissue malignant neoplasm comprising less than 1 % of all soft tissue sarcomas. ASPS demonstrates a strong predilection for adolescents and young adults, with a female predominance reported. The head and neck region is the most commonly affected region in pediatric patients with the tongue and orbit affected most commonly. Herein we present the clinical, radiographic, histopathologic, immunohistochemical and molecular features of two examples of ASPS affecting the oral cavity of 4 and 13 year-old boys, along with a focused review of the literature on intraoral ASPS in pediatric patients.

Retroperitoneal alveolar soft-part sarcoma: A case report

Alveolar soft-part sarcoma is a rare type of malignant soft tissue tumor that usually presents as a painless, slow-growing mass and is easily misdiagnosed as paraganglioma, alveolar rhabdomyosarcoma, clear cell renal cell carcinoma, or granular cell tumor. Alveolar soft-part sarcoma of the retroperitoneum is extremely rare. Here we report a case of retroperitoneal alveolar soft-part sarcoma that was correctly diagnosed based on a combination of imaging, clinical and pathological features and the use of immunohistochemical and gene detection techniques. A literature review was performed to further raise the awareness of this rare disease.