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

Solitary Fibrous Tumor of the Umbilical Region in a Pediatric Patient

Background: Fibrous tumors are rare tumors of mesenchymal origin arising in the serosal surfaces within the body. Although commonly seen in adults, solitary fibrous tumors rarely occur in children. Histopathology and immunohistochemistry are the methods of choice for diagnosing solitary fibrous tumors. Case Report: A 2-year-old male presented with a swelling over the umbilicus for the prior 8 months. The umbilical mass was excised and sent for histopathologic examination. The skin-covered greyish soft tissue mass measured 6 × 5.5 × 4.5 cm, and the cut surface showed a homogenous greyish growth. On microscopic examination, a predominantly well-circumscribed encapsulated tumor was noted, with spindle shaped cells arranged in a haphazard manner and ectatic vascular channels. The cells were immunoreactive for CD34 and signal transducer and activator of transcription 6 (STAT6) and negative for smooth muscle actin, desmin, myogenin, MyoD1, CD99, epithelial membrane antigen, and beta-catenin. Conclusion: The aim of this case is to make clinicians aware of the umbilicus as a rare site of solitary fibrous tumor in children and the diagnostic importance of STAT6.

Malignant giant solitary fibrous tumor of the pleura metastatic to the thyroid gland

PURPOSE

Solitary fibrous tumor (SFT) of the pleura is a rare mesenchymal neoplasm arising from mesenchymal cells in the areolar tissue subjacent to the mesothelial-lined pleura and accounting for less than 5% of primary pleural tumors. SFTs are generally benign and asymptomatic, with 10-year survival rates of up to 98%. Unfortunately, approximately 10% have malignant potential, leading to local recurrence after radical surgery and/or metastatic spread. Of note, giant pleural SFT, which consists of a tumor occupying at least 40% of the affected hemithorax, is even less common with only anecdotal cases reported in the medical literature.

METHODS

We describe a unique case of giant SFT of the pleura that metastasized to the thyroid gland 1 year after complete resection, focusing on its clinical and pathological features of presentation.

RESULTS

En bloc resection remains the mainstay of therapy with curative intent. Patients with large tumors may undergo preoperative angiography with percutaneous embolization of the tumor, which allows to reduce perioperative bleeding. In case of local recurrence, surgery still remains the best treatment option. However, surgery can also be considered in patients with isolated metastatic spread.

CONCLUSIONS

Every suspected and proven SFT of the pleura should undergo surgical resection, as clinical and radiological criteria cannot accurately distinguish benign from malignant forms. Moreover, the peculiar histological features of SFT should not be neglected when planning clinicoradiological follow-up. Additionally, suspicious clinical findings during follow-up should always be thoroughly investigated in order to exclude or confirm the diagnosis of recurrent disease.

Solitary Fibrous Tumor of the Liver: a Review of the Current Knowledge and Report of a New Case

INTRODUCTION

Solitary fibrous tumors of the liver (SFTL) are uncommon tumors; to the present day, less than 50 cases has been reported in the English scientific literature, most of which behaved as benign tumors. The present article reports a new case of SFTL and has the main purpose of updating the current knowledge of SFTL because due to its rarity, its clinical presentation, study, treatment, and prognosis are not well known. The clinical presentation, radiologic study, surgical treatment, immunohistochemical study, and prognosis are updated and comprehensively discussed.

METHODS

Using the common search engines, a search of the English literature was conducted for "Solitary Fibrous Tumor of The Liver," and the relevant articles were retrieved, reviewed, and analyzed.

RESULTS

All published articles reported anecdotal SFTLs, or SFTLs were included in large series analyzing solitary fibrous tumors on different sites.

CONCLUSION

The SFTL is an uncommon neoplasm. The clinical presentation is habitually indolent and its behavior is uncertain. In some cases, the SFTL acts as an aggressive sarcoma with poor prognosis. Currently, only surgery offers a therapeutic opportunity for these patients. Due to the lack of current knowledge of long-term behavior of supposedly benign SFTLs and to the lack of specific therapies, methodical long-term follow-up is essential to ensure the survival of patients treated for SFTL.

An update on primary hepatic solitary fibrous tumor: An examination of the clinical and pathological features of four case studies and a literature review

BACKGROUND

Primary hepatic solitary fibrous tumor is a rare neoplasm that originates in the submesothelial tissue of the liver and is frequently misdiagnosed because of its rarity and unfamiliar characteristics.

AIM

To analyze, summarize and update the clinical and pathological features of primary hepatic solitary fibrous tumor.

METHODS

We systematically extract the clinical data of 4 cases from the relevant medical records, analyze the macroscopic, histological and immunohistochemical features and review the 59 previously reported cases in the English literatures.

RESULTS

The patients' mean age 50.75 years (range, 49-52 years), and the gender ratio was 1:1. The tumors ranged in size from 2.3 to 12.0cm (average diameter, 7.85cm). The tumors were composed of spindle cells with oval, fusiform or banded nuclei that were arranged in bundled, storiform or peculiar random patterns. Mitosis and hemangiopericytoma-like vessels were occasionally observed. Immunohistochemically, three cases were positive for Signal transduction and activator of transcription 6, cluster of differentiation 34, B-cell lymphoma-2 and vimentin but were negative for nervous, muscular and hepatocellular markers. Hepatic lobectomy was performed in all cases, and one patient received adjuvant chemotherapy simultaneously. One patient suffered two recurrences without metastasis, and the remaining patients experienced favorable outcomes.

CONCLUSIONS

A consensus on the essential and definite diagnostic criteria for primary hepatic solitary fibrous tumor must be reached in a timely manner. Signal transduction and activator of transcription 6 is a highly sensitive and specific immunohistochemical marker for primary hepatic solitary fibrous tumor.

STAT6 rabbit monoclonal antibody is a robust diagnostic tool for the distinction of solitary fibrous tumour from its mimics

Recurrent NAB2-STAT6 gene fusions have recently been identified in solitary fibrous tumour by next generation sequencing. Our aim was to examine the sensitivity and specificity of STAT6 immunohistochemistry for solitary fibrous tumour versus other morphologically similar soft tissue tumours. STAT6 expression was evaluated in 54 solitary fibrous tumours of various sites and 99 soft tissue tumours in the histological differential diagnosis. We used a rabbit monoclonal STAT6 antibody (1:100), which has not been reported by others, on formalin fixed, paraffin embedded whole sections and tissue microarray slides. Only nuclear staining of STAT6 was considered positive. Distribution of staining was scored as: 0 (no staining), 1+ (1-25%), 2+ (26-50%), 3+ (>50%). Intensity was scored as weak, moderate or strong. Nuclear STAT6 staining was present in all SFT cases tested (54/54, sensitivity 100%), regardless of histology, anatomical site or CD34 status. The majority of cases showed 3+ and strong staining. All tested cases of cellular angiofibroma (0/9), myofibroblastoma (0/10), spindle cell lipoma (0/10), benign fibrous histiocytoma (0/13), dermatofibrosarcoma protruberans (0/9), low-grade fibromyxoid sarcoma (0/7), schwannoma (0/8), desmoid-type fibromatosis (0/8), monophasic synovial sarcoma (0/11), malignant peripheral nerve sheath tumour (0/7), and mesenchymal chondrosarcoma (0/7) were negative for STAT6 (specificity 100%). Our study further supports the utility of STAT6 immunohistochemistry as an adjunct in the diagnosis of solitary fibrous tumour.

Giant solitary fibrous tumor pleura: Clinical dilemma and diagnosis

Solitary fibrous tumors in the lung are rare neoplasms with distinct clinicopathological and immunohistochemical features. We report a giant solitary fibrous tumor of the pleura in a young male which remained silent clinically till it assumed gigantic proportions. Histology and immunohistochemistry were classical of a solitary fibrous tumor. Inspite of its appalling size it proved to be benign in behavior. This case depicts the vulnerability of this lesion to a clinical bungle. The report highlights the significance of clinical suspicion of this rare neoplasm and reveals the diagnostic associations and procedures to avoid emperical therapy and delay in curative surgical treatment.

Solitary fibrous tumor: is there a molecular relationship with cellular angiofibroma, spindle cell lipoma, and mammary-type myofibroblastoma?

Solitary fibrous tumor (SFT) is a mesenchymal tumor characterized by ovoid cells, branching blood vessels, stromal hyalinization, and CD34 immunoreactivity. Studies have shown loss of 13q in a group of morphologically similar entities, including cellular angiofibroma, mammary-type myofibroblastoma, and spindle cell lipoma. The histologic and immunophenotypic overlap between SFT and the latter group of tumors suggests that these tumors may be genetically linked. We tested a group of 40 SFTs to assess for loss of RB1 (13q14) by fluorescence in situ hybridization (FISH). All 38 SFTs with evaluable signals failed to show loss of RB1 (13q14) by FISH. All cases of cellular angiofibroma (1/1), spindle cell lipoma (6/6), and mammary-type myofibroblastoma (4/4), which were used as a control group, showed monoallelic or biallelic loss of RB1. The absence of RB1 loss in SFTs suggests that they are not related to cellular angiofibroma, mammary-type myofibroblastoma, or spindle cell lipoma.

Solitary fibrous tumor of the central nervous system: a 15-year literature survey of 220 cases (August 1996-July 2011)

We reviewed the world literature on solitary fibrous tumors of the central nervous system from August 1996 to July 2011, focusing on both clinicopathological features and diagnostic findings. The anatomical distribution of the 220 cases reported so far reveals that most are intracranial and just over one-fifth are intraspinal. In decreasing frequency, intracranial tumors involve the supratentorial and infratentorial compartments, the pontocerebellar angle, the sellar and parasellar regions, and the cranial nerves. Intraspinal tumors are mainly located in the thoracic and cervical segments. Although most solitary fibrous tumors of the central nervous system are dural based, a small subset presents as subpial, intraparenchymal, intraventricular, or as tumors involving the nerve rootlets with no dural connection. Preoperative imaging and intraoperative findings suggest meningioma, schwannoma or neurofibroma, hemangiopericytoma, or pituitary tumors. Immunohistochemistry is critical to establish a definitive histopathological diagnosis. Vimentin, CD34, BCL2, and CD99 are the most consistently positive markers. The usual histologic type generally behaves in a benign manner if complete removal is achieved. Recurrence is anticipated when resection is subtotal or when the tumor exhibits atypical histology. The proliferative index as assessed by MIB1 labeling is of prognostic significance. Occasionally, tumors featuring conventional morphology may recur, perhaps because of minimal residual disease left behind during surgical extirpation. Rare extracranial metastases and tumor-related deaths are on record. Surgery is the treatment of choice. Stereotactic and external beam radiation therapy may be indicated for postsurgical tumor remnants and for unresectable recurrences. Long-term active surveillance of the patients is mandatory.

[Solitary fibrous tumor of the meninges: report of three cases]

The authors expose the clinical, radiological and histological presentation of three cases of solitary fibrous tumors of the meninges, initially thought to be meningiomas. Actually, these three cases show typical anatomoclinical features. The authors also mention the differential diagnosis, and recall the essential contribution of immunohistochemistry.

Solitary fibrous tumor

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm which may be found everywhere in the body. It is now distinguished into two forms, pleural and extrapleural, which morphologically resemble each other. Abdominal localizations are quite rare, with 10 cases only reported in bladder; rarely they can be source of paraneoplastic syndromes (i.e., hypoglycemia secondary to insulin-like growth factor). In April 2006 a 74-year-old white male presented with chills, diaphoresis and acute abdominal pain with hematuria. At admission in emergency he underwent an abdominal Xray (no pathological findings) and an ultrasound examination of the kidneys and urinary tract, which revealed a pelvic hyperechogenic neoformation measuring approximately 10×8×7 cm, compressing the bladder. Blood chemistry at admission revealed only a mild neutrophilic leucocytosis (WBC 16600, N 80%, L 11%), elevated fibrinogen and ESR, and hypoglycemia (38 mg/dL). Macro scopic hematuria was evident, while urinocolture was negative. Contrast enhanced CT scan of the abdomen and pelvic region revealed a large round neoformation dislocating the bladder, with an evident contrast-enhanced periphery and a central necrotic area. Continuous infusion of glucose 5% solution was necessary in order to maintain blood glucose levels above 50 mg/dL. The patient underwent complete surgical resection of an ovoidal mass coated by adipose tissue, with well delimited margins; histological findings were consistent with solitary fibrous tumor (SFT). Hypoglycemia resolved completely with removal of the growth. In this case report we describe a SFT growing in the bladder, a quite rare localization, which presented a unique hypoglycemia. In contrast to the majority of cases reported in the literature, the behavior of this SFT was not aggressive, and, since the patient is still alive, surgical resection was considered conclusive.

A not so solitary fibrous tumor of the liver

Solitary fibrous tumor (SFT) is a rare neoplasm. Liver parenchyma is a rare location of SFT and, in this case, it usually follows a benign course. We report here the case of a 54-year-old man who presented a large SFT tumor of the right hepatic lobe. The tumor was surgically resected. Local recurrence occurred 6 years later as a 15 cm diameter liver tumor. Histological examination of the resected lesion showed features of an aggressive form of SFT. Two years later, the patient presented with complaints of neck pain and ensuing examinations revealed a tumor of the cranial base. A new surgical resection was performed and histological examination confirmed a metastasis of the SFT. Few weeks later, the patient presented an irreducible psoitis due to an iliac bone metastasis. He died within 1 month.

[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.

Solitary fibrous tumor arising in an intrathoracic goiter

BACKGROUND

Solitary fibrous tumor (SFT) is a rare spindle cell tumor most often found in the mediastinal pleura. Nineteen cases of SFT arising in the thyroid gland have been reported. We report a case of SFT of the thyroid gland with immunohistochemical and cytogenetic investigation.

SUMMARY

A 58-year-old man had pulmonary symptoms, thought to be asthma. Computed tomographic scan revealed a large goiter with a solid hyperechoic nodule. The results of thyroid function tests were normal. Microscopically, the lesion was composed of fibroblast-like spindle cells in a patternless growth. Cellular atypia or necrosis was not seen, and mitotic activity was low. Immunohistochemistry showed positive reaction for CD34, vimentin, bcl-2, and CD99. Fluorescence in situ hybridization analysis of more than 100 cells exhibited no trisomy 21. Complete surgical removal of tumor is the treatment of choice.

CONCLUSION

The histological appearance and immunohistochemical reaction pattern of SFT is characteristic. The entity should be considered when dealing with a spindle cell lesion in the thyroid gland. All cases of this site of origin reported have had a benign clinical course. As only a small number of cases have been described, we recommend long-term follow-up.

Oral solitary fibrous tumor: a cytogenetic analysis of tumor cells in culture with literature review

Solitary fibrous tumor (SFT) is an uncommon spindle-cell neoplasm of mesenchymal origin. Because the pathogenetic background of SFT is still controversial, cytogenetic analysis could help in tumor diagnosis and prognosis. In this study, cultured SFT cells from a lower lip lesion that presented characteristic immunopositivity for CD34, vimentin, CD99, and BCL2 showed a unique cytogenetic finding: 46,XX,inv(2)(p21q35),t(3;12)(q25;q15). To our knowledge, this is the third report of cytogenetic result of a case involving the oral cavity. The SFT cells in culture that maintained their immunohistochemical expression of diagnostic molecules, showed unique chromosomal changes previously unreported when compared with already documented ones. Our data suggest that the complicated pathogenetic nature of SFT is possibly tumor- or organ-related.

New insights into the hemangiopericytoma/solitary fibrous tumor spectrum of tumors

PURPOSE OF REVIEW

This review provides an overview of the hemangiopericytoma/solitary fibrous tumor (HPC/SFT) spectrum of tumors, focusing on the histopathologic characteristics, clinical features, diagnosis, and treatment of HPC/SFT.

RECENT FINDINGS

Due to the relatively insensitive nature of HPC/SFT to radiotherapy and cytotoxic chemotherapy, new therapies are needed for treatment of advanced disease. Inhibition of angiogenic pathways may provide a novel therapeutic mechanism for targeting this malignancy. Combination therapy with temozolomide and bevacizumab has recently emerged as a potentially promising regimen for HPC/SFT.

SUMMARY

With many novel targeted therapies currently in development for soft tissue sarcomas, a better understanding of the molecular pathogenesis and aberrations of HPC/SFT is needed to determine optimal therapeutic agents. Identifying appropriate targets and designing rational prospective clinical trials will not only improve treatment of HPC/SFT but will also lead to a new paradigm of personalized, targeted therapy.