Pleural malignant solitary fibrous tumor with sarcomatous overgrowth showing PDGFRbeta mutation

The radiation therapy options of intracranial hemangiopericytoma: An overview and update on a rare vascular mesenchymal tumor

Hemangiopericytoma (HPC) is an extremely rare hypervascular tumor of mesenchymal lineage. It tends to recur and to develop distant metastases even many years after primary surgical resection. The management of recurrent and metastatic disease is not always so well defined. A complete surgical resection does not eliminate the high risk of local recurrences that occur in the central nervous system, often in the same surgical bed. However, treatment with adjuvant radiotherapy even in cases of complete resection remains controversial. Because of its rarity, there is no standard for treatment. We focused on radiotherapy treatment options, analyzing the literature and making a base on conduct further studies to establish the standard radiation dose to be used for locoregional control of such a complex and extremely rare disease and to help specialists to take the most appropriate therapeutic option.

Postoperative Radiotherapy for the Treatment of Solitary Fibrous Tumor With Malignant Transformation of the Pelvic: A Rare Case Report With Literature Review

Solitary fibrous tumor of the pelvic is an uncommon neoplasm with nonspecific symptoms. Reports of malignant transformation are especially rare. We report a case of solitary fibrous tumor in pelvic. A unique feature of our case compared with previously reported is that this patient relapsed with malignant transformation and had significant response to radiotherapy. The patient was initially treated with surgery, followed by postoperative dimensional conformal intensity modulated radiation therapy (dynamic MLC VRIAN 23EX Linac, inversely optimized by the Eclipse system) to provide a radical cure for residual tumor.In this case, there were no signs of recurrence after six and a half years of further follow-up, indicating that postoperation radiotherapy may be an effective treatment for SFT with malignant transformation in pelvic.

Recurrent intrathoracic solitary fibrous tumor: Remarkable response to radiotherapy

Solitary Fibrous Tumor of the Pleura (SFTP) is an uncommon neoplasm which grows slowly. For some cases, surgery is warranted. However, for unresectable ones, the standard strategy has not been established yet. We presented a rare case of recurrent malignant intrathoracic solitary fibrous tumor. It was impossible to resect the tumor. Radiotherapy alone achieved a significant improvement effect.

Successful use of pazopanib for treatment of refractory metastatic hemangiopericytoma

Hemangiopericytoma is a rare disease entity of soft-tissue sarcoma (STS) that can be cured with surgical resection. In cases of inoperable recurrence or metastasis, palliative chemotherapy is indicated, though there is currently no approved chemotherapy regimen. Therefore new treatment regimens are needed.

We describe three cases of metastatic hemangiopericytoma. In the first case, five lines of chemotherapeutic agents were used unsuccessfully in a patient with a 12-year history of metastatic hemangiopericytoma. After one cycle of pazopanib therapy, however, chest radiography showed a decrease in tumor volume of more than 30%. A marked decrease in FDG uptake on PET CT was also noted, and the patient is now on her 5^th month of pazopanib therapy. The second case is a patient with a brain hemangiopericytoma with multiple liver, lung, and bone metastases. Pazopanib induced radiologic stabilization of metastatic disease over the course of 8 months. The third case is a patient with a retroperitoneal hemangiopericytoma with pleural and peri-renal metastases. For more than 8 months, he has exhibited stable disease with pazopanib treatment.

Pazopanib may be useful for treatment of metastatic hemangiopericytoma, though further studies are needed to confirm the efficacy of this medication and to investigate its molecular mechanism of action.

CD34-negative solitary fibrous tumour resistant to imatinib

A 75-year-old man presented to our hospital with multifocal thickening of the left pleura and left pleural effusion. Histology of the pleura showed uniform and bipolar spindle cells with moderate mitosis in a collagenised stroma. It further showed abundant blood vessels in a haemangiopericytoma-like pattern. These findings were strongly suggestive of malignant solitary fibrous tumour (SFT). The tumour showed negative staining for CD34. The loss of CD34 expression could imply histologically high-grade tumour, as reported previously. Imatinib, a multityrosine kinase inhibitor with targets, including platelet-derived growth factor receptor (PDGFR)-α and PDGFR-β, has antitumour activity in some patients with SFT. Unfortunately, imatinib treatment failed to control disease progression in the present case that expressed PDGFR-β, but not PDGFR-α. This report described a case of CD34-negative SFT resistant to imatinib.

Gene expression profiling of solitary fibrous tumors

Background

Solitary fibrous tumors (SFTs) are rare spindle-cell tumors. Their cell-of-origin and molecular basis are poorly known. They raise several clinical problems. Differential diagnosis may be difficult, prognosis is poorly apprehended by histoclinical features, and no effective therapy exists for advanced stages.

Methods

We profiled 16 SFT samples using whole-genome DNA microarrays and analyzed their expression profiles with publicly available profiles of 36 additional SFTs and 212 soft tissue sarcomas (STSs). Immunohistochemistry was applied to validate the expression of some discriminating genes.

Results

SFTs displayed whole-genome expression profiles more homogeneous and different from STSs, but closer to genetically-simple than genetically-complex STSs. The SFTs/STSs comparison identified a high percentage (∼30%) of genes as differentially expressed, most of them without any DNA copy number alteration. One of the genes most overexpressed in SFTs encoded the ALDH1 stem cell marker. Several upregulated genes and associated ontologies were also related to progenitor/stem cells. SFTs also overexpressed genes encoding therapeutic targets such as kinases (EGFR, ERBB2, FGFR1, JAK2), histone deacetylases, or retinoic acid receptors. Their overexpression was found in all SFTs, regardless the anatomical location. Finally, we identified a 31-gene signature associated with the mitotic count, containing many genes related to cell cycle/mitosis, including AURKA.

Conclusion

We established a robust repertoire of genes differentially expressed in SFTs. Certain overexpressed genes could provide new diagnostic (ALDH1A1), prognostic (AURKA) and/or therapeutic targets.

Solitary fibrous tumours of the pleura: report of two cases and literature review

BACKGROUND

Solitary fibrous tumours of the pleura (SFTPs) are rare pleural mesenchymal neoplasms with distinct clinicopathological and immunohistochemical features, accounting for less than 5 % of all neoplasms involving the pleura.

METHODS

We present two cases of SFTP with a review of the current literature.

RESULTS

Clinical presentation varies according to size and intrathoracic localisation. The molecular pathology of SFTPs is largely unknown. Complete surgical resection is recommended with long-term clinic and radiographic follow-up due to its malignant potential.

CONCLUSIONS

This is a summary of available literature outlining current clinical practice in the diagnosis, management, and treatment of SFTPs in Ireland.

Solitary fibrous tumors and so-called hemangiopericytoma

We have reviewed the literature data regarding the spectrum of tumors including solitary fibrous tumor and hemangiopericytoma with special focus on definition of the disease, discussion of the criteria for malignancy, and the key elements of standard treatment of localized disease. We have discussed the emerging concepts on the tumor biology and the different systemic treatments (chemotherapy and molecular-targeted therapies).

Solitary fibrous tumour of the pleura: A case report

Solitary fibrous tumours of the pleura are rare pleural neoplasms that are distinct from mesothelioma. Most of them are benign, although some behave aggressively; morphological and pathological features are important in distinguishing them from mesothelioma and in predicting clinical behaviour. Solitary fibrous tumours often grow to a large size before causing symptoms, and are characteristically associated with hypertrophic pulmonary osteoarthropathy in up to 20% of cases. In cases of benign lesions, complete resection is usually curative. A case involving a 62-year-old woman who underwent surgical resection of a solitary fibrous tumour of the pleura measuring 25 cm in size is described.

[Primary malignant solitary fibrous tumor/hemangiopericytoma of the parotid gland]

Solitary fibrous tumor (SFT) was first described in the pleura by Lietaud in 1767; later in 1870, Wagner described the localized nature of this type of tumor and Klemperer and Rabin classified pleural tumors into two types: diffuse mesotheliomas and localized mesotheliomas. Recent years have seen the redefinition of this neoplasm, due to better technology; it is now proven that this neoplasm may have multiple different extrapleural origins including the head and neck regions. This diversity of locations is related to the particular mesenchymal histogenesis of SFT which allows its development from very unusual sites such as the salivary glands (SGs). In this particular site, this neoplasm is very infrequent and most of reported cases refer to benign disease, with just one case informed so far of primary malignant SFT.

IGF2 over-expression in solitary fibrous tumours is independent of anatomical location and is related to loss of imprinting

Solitary fibrous tumour (SFT) is a mesenchymal neoplasm composed of CD34-positive fibroblastic cells. The pathogenesis driving this neoplasm remains unclear, with no recurrent genetic aberrations described to date. Previous reports suggest a role for IGF2 over-expression in the pathogenesis of these tumours, implicated in triggering hypoglycaemia in some patients. The expression profiling of 23 SFTs was investigated using an Affymetrix U133A platform. The transcriptional signature was compared to a set of 34 soft tissue sarcomas spanning seven subtypes. Potential candidate genes were then further investigated for activating mutations or loss of imprinting (LOI). SFT had a distinct expression signature and clustered in a tight genomic cluster, separate from all other sarcoma subtypes. A number of over-expressed receptor tyrosine kinase (RTK) genes were identified in SFT, including DDR1, ERBB2 and FGFR1; however, no mutations were identified by cDNA sequencing. Over-expression of IGF2 was uniformly detected in SFT, regardless of anatomical location, and was related to LOI. In contrast, IGF1 and JUN over-expression was seen in pleural, but not meningeal, locations. SFT shows a distinctive expression signature, with over-expression of DDR1, ERBB2 and FGFR1. Despite of lack of activating mutations in these RTKs, therapy with specific inhibitors targeting these kinases might be considered in advanced/metastatic cases. Our results confirm LOI in several tumours expressing high levels of IGF2, which may explain the observed paraneoplastic hypoglycaemia.

Multicenter phase II trial of sunitinib in the treatment of nongastrointestinal stromal tumor sarcomas

PURPOSE To evaluate the potential benefit of continuous daily dosing sunitinib in patients with advanced nongastrointestinal stromal tumor (GIST) sarcomas. PATIENTS AND METHODS A total of 53 patients with advanced non-GIST soft tissue sarcomas received sunitinib 37.5 mg daily. Primary end point was Response Evaluation Criteria in Solid Tumors defined response. Secondary end points were stable disease at 16 and 24 weeks. [(18)F]-fluorodeoxyglucose positron emission tomography was performed on a subset of 24 patients at baseline and after 10 to 14 days of therapy. Results Forty-eight patients were eligible for response. One patient (desmoplastic round cell tumor [DSRCT]) achieved a confirmed partial response (PR) and remained on study for 56 weeks. Ten patients (20%) achieved stable disease for at least 16 weeks. Metabolic PR was seen in 10 (47%) of 21 of patients. Metabolic stable disease was seen in 11 (52%) of 21. There were no unexpected toxicities observed. CONCLUSION Sunitinib demonstrated notable evidence of metabolic response in several patients with non-GIST sarcoma. The relevance of disease control observed in subtypes with an indolent natural history is unknown, however, the durable disease control observed in DSRCT, solitary fibrous tumor, and giant cell tumor of bone suggests that future evaluation of sunitinib in these subtypes may be warranted.

Lack of a common or characteristic cytogenetic anomaly in solitary fibrous tumor

Solitary fibrous tumor is a mesenchymal tumor that was initially described as a pleural-based lesion, but later was discovered in many other locations. The light-microscopic appearance of solitary fibrous tumor may overlap with other diagnostic entities; however, consistent tumor cell CD34 immunoreactivity is useful in establishing the diagnosis. Limited data suggest that solitary fibrous tumors are karyotypically diverse, and no common or characteristic anomaly has yet emerged for this entity. Cytogenetic analysis of two solitary fibrous tumors, one peritoneal and the other arising in the liver, revealed predominantly structural abnormalities in the former and numerical imbalances in the latter. Clonal karyotypic abnormalities were lacking in three additional solitary fibrous tumors.