Surgical treatment of primary solitary fibrous tumors involving the pelvic ring

A Single Pelvic Fibrous Tumor Associated With Doege-Potter Syndrome: A Case Study

Doege-Potter syndrome (DPS) is a very rare paraneoplastic condition that is marked by hypoglycemia brought on by a solitary fibrous tumor rather than an islet cell tumor. Soft tissue neoplasms termed as solitary fibrous tumors (SFTs) are rare and these tumors vary in the site of origin, from the pleural cavity, mediastinum, pericardium, retroperitoneal spaces, liver, thyroid, orbit, bladder, intestines, and soft tissues, while pelvic-derived fibrous tumors are incredibly unusual. There are currently extremely few documented cases and literature reviews both domestically and internationally. In this case study, we present an 82-year-old woman who developed DPS as a result of malignant pelvic SFTs. Her hypoglycemia was clinically healed after she underwent laparoscopic retroperitoneal tumor resection in our institution, and thereafter, her quality of life improved.

Risk factors for recurrent disease after resection of solitary fibrous tumor: a systematic review

Introduction

Solitary fibrous tumor (SFT) is a rare soft tissue tumor found at any site of the body. The treatment of choice is surgical resection, though 10%-30% of patients experience recurrent disease. Multiple risk factors and risk stratification systems have been investigated to predict which patients are at risk of recurrence. The main goal of this systematic review is to create an up-to-date systematic overview of risk factors and risk stratification systems predicting recurrence for patients with surgically resected SFT within torso and extremities.

Method

We prepared the review following the updated Prisma guidelines for systematic reviews (PRISMA-P). Pubmed, Embase, Cochrane Library, WHO international trial registry platform and ClinicalTrials.gov were systematically searched up to December 2022. All English studies describing risk factors for recurrence after resected SFT were included. We excluded SFT in the central nervous system and the oto-rhino-laryngology region.

Results

Eighty-one retrospective studies were identified. Different risk factors including age, symptoms, sex, resection margins, anatomic location, mitotic index, pleomorphism, hypercellularity, necrosis, size, dedifferentiation, CD-34 expression, Ki67 index and TP53-expression, APAF1-inactivation, TERT promoter mutation and NAB2::STAT6 fusion variants were investigated in a narrative manner. We found that high mitotic index, Ki67 index and presence of necrosis increased the risk of recurrence after surgically resected SFT, whereas other factors had more varying prognostic value. We also summarized the currently available different risk stratification systems, and found eight different systems with a varying degree of ability to stratify patients into low, intermediate or high recurrence risk.

Conclusion

Mitotic index, necrosis and Ki67 index are the most solid risk factors for recurrence. TERT promoter mutation seems a promising component in future risk stratification models. The Demicco risk stratification system is the most validated and widely used, however the G-score model may appear to be superior due to longer follow-up time.

Systematic Review Registration

CRD42023421358.

Diagnostics and Treatment of Extrameningeal Solitary Fibrous Tumors

Solitary fibrous tumors (SFT) are rare mesenchymal neoplasms that account for less than 2% of all soft tissue masses. In the latest WHO 2020 Classification of Soft Tissue Tumors, extrameningeal SFT was listed as intermediate (rarely metastasizing) or malignant neoplasms. Due to the lack of characteristic clinical features, their diagnosis and treatment remain challenging. The pathogenesis of SFT is often associated with the presence of fusions of the NAB2-STAT6 gene on the 12q13 chromosome. Cytoplasmic CD34 positive staining is considerably characteristic for most SFTs; less frequently, factor XII, vimentin, bcl-2, and CD99 are present. A key factor in the diagnosis is the prevalent nuclear location of STAT6 expression. Radical resection is the mainstay of localized SFTs. In the case of unresectable disease, only radiotherapy or radio-chemotherapy may significantly ensure long-term local control of primary and metastatic lesions. To date, no practical guidelines have been published for the treatment of advanced or metastatic disease. Classical anthracycline-based chemotherapy is applicable. The latest studies suggest that antiangiogenic therapies should be considered after first-line treatment. Other drugs, such as imatinib, figitumumab, axitinib, and eribulin, are also being tested. Definitive radiotherapy appears to be a promising therapeutic modality. Since standards for the treatment of advanced and metastatic diseases are not available, further investigation of novel agents is necessary.

Malignant retroperitoneal solitary fibrous tumor co-existing with Meigs' syndrome: A case report

Malignant solitary fibrous tumors in the retroperitoneum are rare, and their treatment strategies have not yet been established. A 61-year-old woman with dyspnea underwent laparotomy under a presumptive diagnosis of Meigs' syndrome. She underwent both adnexectomy and retroperitoneal tumor excision. The histologic diagnosis was of a fibrothecoma of both ovaries and a retroperitoneal solitary fibrous tumor that was considered malignant based on its mitotic activity. Local recurrence was observed 9 months postoperatively; re-excision was performed, and radiation therapy was administered. Four months later, metastasis to the left lung was detected, and a thoracoscopic resection was performed. Although pazopanib was administered subsequently, it was discontinued after 11 months because of proteinuria. She complained of dysphagia 3 weeks after the withdrawal of the drug, and a metastatic tumor was observed at the cranial base. Radiotherapy was initiated; however, she died of the disease 35 months after the primary surgery. Medical guidelines should be established for malignant solitary fibrous tumors to improve patient prognosis.

Tumor Fibroso Solitário Primário em Região Pélvica: Relato de Caso

Introdução: O tumor fibroso solitário é uma neoplasia mesenquimal rara, originada de células intersticiais dendríticas CD34 positivas e composta pela justaposição de células fusiformes. Os casos iniciais foram primariamente descritos na região torácica, e o principal sítio, a pleura visceral. Raramente são descritos casos de tumor fibroso solitário extrapleural em região pélvica, demonstrando a possibilidade de múltiplas sítios primários. Relato do caso: Paciente de 38 anos, sexo feminino, previamente saudável e assintomática, procurou orientação médica após uma ultrassonografia pélvica de rotina evidenciar uma imagem heterogênea na região anexial direita, paraovariana, sendo submetida à ressecção cirúrgica da lesão, com diagnóstico de tumor fibroso solitário confirmado por imuno-histoquímica. Discutem-se os aspectos do diagnóstico imuno-histoquímico e do tratamento cirúrgico. Conclusão: Os casos de tumor fibroso solitário em região pélvica podem ser descobertos por meio de ultrassonografia pélvica de rotina. O tratamento cirúrgico, com ressecção ampliada e margens negativas, deve ser o principal objetivo nos casos de tumor fibroso solitário em região pélvica. A obtenção de amostras para análise imuno-histoquímica é recomendada, e a positividade para CD34 e STAT6 aponta o diagnóstico. Recidivas podem ocorrer em até uma década de seguimento, sendo recomendado período longo de acompanhamento pós-cirúrgico.

Diagnostic challenges and treatment options in patients with solitary fibrous tumor: A single-center observational study

Introduction

Solitary fibrous tumor (SFT) is an extremely rare disease with a high misdiagnosis rate and a potentially malignant biologic nature. We have collected and analyzed data from 18 SFT patients to provide a deeper insight into this uncommon disease entity.

Methods

In our study, 18 patients who had undergone surgery between April 2014 and December 2021 for the diagnosis of SFT were evaluated. The collected data for each patient included the location of the SFT, the preoperative diagnosis, the definitive histological diagnosis, the presence of postoperative complications, the time of recurrence, the time of systemic progression, the type of treatment, and the survival rate. The median follow-up was 36 months.

Results

In three patients, the preoperative diagnosis did not correlate with the definitive histology of SFT. In patients with the limb location of SFT, no signs of recurrence nor distant metastases were seen within the study period. In total, 50% of the postsurgical complications were associated with the abdominal location of the SFT. In newly diagnosed SFT patients, two patients (20%) developed local recurrence, and the median time until recurrence was 22.5 months. Out of patients that were admitted and operated on for recurrent SFT, 67% relapsed, and the median time to relapse was 9.5 months. The systemic progression of the disease was observed in 33% of patients treated for recurrent SFT.

Conclusion

In our study, the misdiagnosis rate was high and correlated with previously published studies. Postsurgical complications were associated with the extrathoracic location of SFT. The mainstay of SFT treatment remains radical surgery, although radiotherapy alone can significantly improve overall survival. Clinical trials are urgently needed to evaluate the potential effect of other treatment modalities, such as immunotherapy and targeted therapy, in SFT patients.

A case of a large solitary fibrous tumor arising from the retroperitoneum resected completely using an intra-aortic balloon

Solitary fibrous tumors (SFTs) are rare mesenchymal cell-derived tumors that can cause substantial bleeding during surgery due to hyper-vascularization. We report a case of a large retroperitoneal SFT resected completely using an intra-aortic balloon. A 71-year-old female with a history of type 2 diabetes mellitus presented with a tumor that was diagnosed as an insulin-like growth factor-II-producing benign SFT using computed tomography-guided biopsy. The tumor had grown from 6 to 20 cm in diameter within 4 years, with concurrent and severe hypoglycemia. Preoperative computed tomography findings showed substantial blood flow toward the tumor. The retroperitoneal tumor was observed to be widely attached. Substantial hemorrhaging during tumor resection was observed despite vascular embolism. We inflated the intra-aortic balloon for 45 min and resected the tumor completely. In conclusion, large SFT resection requires preoperative tumor blood flow evaluation and preparation of both a vascular embolism and an intra-aortic balloon.

A Case Report of Rare Sacral Solitary Fibrous Tumor

Huge primary epidural solitary fibrous tumors in the sacrum are a rare clinical entity. The purpose of this article is to present our experience in treating such large and complex neoplasms in a 31-year-old woman. The patient complained of constant nocturnal bilateral hip and lower back pain and unilateral radicular symptoms (numbness, paresthesias) in the left S1/S2 dermatomal distribution. Diagnostic imaging, biopsy, preoperative endovascular embolization, two-staged tumor resection, and lumbosacroiliac fusion were performed. The treatment resolved the patient's neurological symptoms and resulted in overall good postoperative functionality. The patient has been in remission for more than five years despite her refusal of adjuvant radiotherapy.

Transcatheter arterial embolization of malignant pelvic solitary fibrous tumor: case report and literature review

Pelvic malignant solitary fibrous tumor (SFT) is a relatively rare disease, and literature on radical resection with transcatheter arterial embolization of pelvic SFT is lacking. In this work, we report on a 55-year-old man with a presacral mass who was hospitalized at our department. Computed tomography and magnetic resonance imaging indicated pelvic space-occupying lesions that were 12 cm × 10 cm in size and pelvic lesions that were not clearly demarcated from the right posterior wall of the bladder and the right ureter. This result suggested severe secondary hydronephrosis of the right renal pelvis. The patient underwent transcatheter iliac arterial embolization. Radical tumor resection was performed, and the results of pathological examination confirmed the diagnosis of malignant pelvic SFT. There was no SFT recurrence in this patient at 1-year follow-up. Herein, we report on the treatment of a patient with malignant pelvic SFT, a rare condition, who underwent successful radical resection after transcatheter arterial embolization. Transcatheter arterial embolization can block the blood supply of the SFT as much as possible and improve the possibility of tumor resection. In the future, pelvic SFTs can be considered improving the resection rate by transcatheter arterial embolization before surgery.

A Comprehensive Review on Solitary Fibrous Tumor: New Insights for New Horizons

Simple Summary

Solitary fibrous tumor (SFT) is a malignant condition that exhibits different clinical behaviors ranging from low to high aggressive SFT, with dedifferentiated SFT (DD-SFT) being the fastest-growing subtype. Even when surgery alone provides curation rates above 60%, recurrences do occur in a fraction of patients where surgery is unable to provide disease control. Among the systemic therapeutic options, antiangiogenic compounds have shown higher efficacy than chemotherapy by indirect comparisons. Furthermore, rotating different antiangiogenics, at the progression time, has been shown to be effective. The exception is DD-SFT since it is resistant to antiangiogenics but can respond to chemotherapy. This comprehensive review also analyzes the underlying molecular components that play a key role in SFT origin and aggressiveness. The discovery in 2013 of anomalous fusion genes between NAB2 and STAT6 was determinant to increase the knowledge on the molecular drivers in SFT that could be potential targets for future therapies.

Abstract

Solitary fibrous tumor (SFT) is a rare mesenchymal, ubiquitous tumor, with an incidence of 1 new case/million people/year. In the 2020 WHO classification, risk stratification models were recommended as a better tool to determine prognosis in SFT, to the detriment of “typical” or “malignant” classic terms. The risk for metastasis is up to 35–45%, or even greater, in series with a longer follow-up. Over the last few decades, advances in immunohistochemistry and molecular diagnostics identified STAT6 nuclear protein expression and the NAB2–STAT6 fusion gene as more precise tools for SFT diagnosis. Recent evidence taken from retrospective series and from two prospective phase II clinical trials showed that antiangiogenics are active and their sequential use from first line should be considered, except for dedifferentiated SFT for which chemotherapy is the best option. Since the fusion transcript driver’s first description in 2013, new insights have been brought on key molecular events in SFT. This comprehensive review mainly focuses on the superior efficacy of antiangiogenics over chemotherapeutic agents in SFT, provides the current knowledge of key molecules that could co-drive the SFT behavior, and suggests new target candidates that deserve to be explored in preclinical and clinical research in SFT.

Perianal Solitary Fibrous Tumor in a Rare Anatomical Presentation: A Case Report and Literature Review

BACKGROUND Solitary fibrous tumors (SFTs) account for <2% of all soft tissue tumors and are slow-growing neoplasms of mesenchymal origin, which have been reported in various locations. They are frequently observed at the pleura and a perianal location is extremely rare. They show no predisposition by sex, are mainly benign, and usually occur between the 5th and 7th decades of life. CASE REPORT We report the case of an 80-year-old man with no comorbidities except hypertension, who presented with an asymptomatic perineal mass. Magnetic resonance imaging showed a solid tumor measuring 3.5×2.5 cm identified in the perineal midline. It was very close to the anal sphincter, showing no extension to the rectum or anus. The tumor was completely excised with negative margins. The postoperative course was uneventful and he was discharged home, free of any symptoms. The pathological examination showed a benign completely excised SFT, and no further treatment was necessary. At the 6-month and 1-year follow-ups, there was no sign of recurrence. CONCLUSIONS A comprehensive review of all the reported cases of perianal SFTs shows that the majority of these tumors present with no symptoms and have a favorable prognosis. Diagnosis is possible only after a pathological examination. The criterion standard of treatment is complete excision with negative margins. Once excised, the tumors have low rates of recurrence and metastasis. Tumors very close to the anal sphincter and with malignant potential need to be operated on with extra care to obtain clear margins without disrupting the continence mechanism.

Novel technical modifications of hand-assisted laparoscopic dissection of a large obturator mass: A case report and literature review

Laparoscopic lateral pelvic tumor dissection (LLPTD) for transobturator tumors may be technically challenging due to the requirement for sufficient operative space. The present study discusses a technique modification with combination of the laparoscopic approach and hand-assisted (HA) open surgery for patients with large obturator masses. LLPTD was performed using the combined approach, defined as HA-LLPTD, with one case treated. According to this technique, a combined working space is constructed based on the outreached laparoscopic space and open extraperitoneal approach, followed by HA-LLPTD. Finally, a literature review was performed to retrospectively evaluate 17 cases of obturator tumors, in terms of tumor type and operative approach. The tumor in the present case was successfully and completely resected, without any obvious intra- and post-operative complications. Based on the literature review, the majority of the cases were benign (~75%) and originated from neurological tissue (~50%). The selection of the operative approach was either open or minimally invasive (50% each). HA-LLPTD allows experienced urological laparoscopic surgeons to safely and completely perform obturator surgery without obstruction of the obturator foramen or formation of intraperitoneal adhesions and associated complications. Therefore, HA-LLPTD may be more useful for transobturator tumor resection compared with the conventional intraperitoneal approach.

Two cases of primary solitary fibrous tumor in the pelvis resected using laparoscopic surgery

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The preoperative diagnosis of the solitary fibrous tumors is difficult irrespective of usage of the various imaging modalities.

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The technique of lateral pelvic lymph node dissection is useful for the extirpation of SFTs around the obturator cavity.

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Immunohistochemical examination of the specimens revealed STAT6 (+) and the NAB2-STAT6 fusion gene was detected in one case.

Background

We report two resected cases of solitary fibrous tumors (SFT) that were accidentally found in the pelvic cavity.

Case presentation

Case 1 was a 54-year-old male. A colonoscopy for the examination of intestinal polyps revealed an extramural tumor in the right anterior wall of the low rectum. A preoperative MRI showed a well-demarcated T1 low and T2 mixed intensity extramural tumor (53 × 36 mm) located right lateral to the low rectum and behind the seminal vesicle. Laparoscopic surgery was successful for tumor extirpation. Immunohistochemical examination of the specimen revealed STAT6 (+) and CD34 (+) cells, a Ki67 positivity of 7–8%, a mitotic index of 4–5/50 HPF, and a diagnosis of SFT. There was no recurrence 29 months after surgery. Using RT-PCR and sequencing, we detected the NAB2-STAT6 fusion gene but the locus of genomic inversion was not detected. Case 2 was a 43-year-old male that received conservative treatment for appendicitis. A CT scan accidentally revealed a tumor of 40 mm of length in the left obturator area. A MRI revealed a well-demarcated T1 and T2 high intensity tumor. The patient underwent surgical biopsy. Immunohistochemical examination of the biopsy revealed STAT6 (+) and CD34 (+) cells, Ki67 positive cells < 1%, and a diagnosis of SFT. We could not detect the NAB2-STAT6 fusion gene in the extirpated tumor.

Conclusions

Two cases of pelvic SFT were diagnosed by immunohistochemical examination, RT-PCR and sequencing and successfully resected by laparoscopic surgery.

Assessment of patient experiences following total sacrectomy for primary malignant sacral tumors: A qualitative study

BACKGROUND AND OBJECTIVES

Few reports have investigated patient experiences following total en bloc sacrectomy. The aims of this study were to obtain a deeper understanding of patients' personal experiences, needs, and satisfaction with the treatment to reveal areas in which perioperative and long-term patient care can be improved.

METHODS

A qualitative design was applied to examine patient experiences and supportive care needs. Patients treated between 2007 and 2017 were identified from our institutional database.

RESULTS

A total of 28 survivors were interviewed (13 females, age 13-75 years). Eight themes were identified: the effect of surgery on patients' (a) daily lives, (b) social activities, (c) work or school activities, (d) and family lives; (e) acceptance of ostomy surgery; (f) need for guidance regarding long-term rehabilitation; (g) satisfaction with the medical services provided in the hospital; and (h) satisfaction with the treatment outcomes.

CONCLUSION

Total en bloc sacrectomy can yield satisfactory oncological outcomes; however, the procedure is a life-changing event for patients and their families. Physicians must provide long-term support and guidance after surgery to enable patients to fully understand and cope with the changes in their lives.