Pleural Solitary Tumors - Long-Term Prognosis Related To Surgery And Clinicopathological Criteria.

INTRODUCTION: Pleural solitary fibrous tumors (SFTs) are indolent mesenchymal neoplasias, generally with good prognosis, for which complete surgical resection is the gold standard. However, local recurrences and distant metastases are reported at variable rates. Risk-assessing criteria and models determining recurrence and metastatic risk have been proposed, and can impact on patient follow-up strategies. METHODS: We conducted an observational study comprising a 12 years period to characterize a cohort of 20 surgically resected thoracic SFTs, and to retrospectively assess the prognostic value of England's histology criteria and Demicco's 4-tier model. RESULTS: All tumors were pleural-based, 12 patients were women, and the mean age at diagnosis was 62.8 years. The median duration of follow-up was ten years, and at the end of the follow-up, all patients were alive, and no distant metastases were reported. Three cases (15%) had local recurrence at the median time of 89.3 months/7.4 years. The only case with an incomplete surgical resection relapsed. Collectively, tumors with worst prognostic features, specifically a positive margin or tumors with malignant histology or non-low-risk features, according to England's and Demicco's models, respectively, were associated with recurrence. CONCLUSION: These results confirm the importance of complete surgical resection of SFTs, and show that risk stratification criteria and models can predict important surgical outcomes such as recurrence. Moreover, they support a risk-based follow-up schedule, as patients with higher relapse risk can benefit from close follow-up.

Solitary fibrous tumor of the pleura with air cystic component.

We present an uncommon case of a solitary fibrous tumor of the pleura with the appearance of an air-containing cystic mass. We discuss the differential diagnosis through the imaging findings, the hypothetical origins of the air component, and the possible relationship between the air component and the aggressivity of the tumor.

Solitary fibrous tumours of the pleura: do we need a different perspective on malignancy?

OBJECTIVES: Solitary fibrous tumours of the pleura (SFTP) are historically considered to be benign soft tissue neoplasms. However, a clinical relevant number of these neoplasms have malignant histological features. The objective of this study was to evaluate the percentage of SFTP presenting unfavourable clinical behaviour in order to predict negative long-term outcome. METHODS: A retrospective review of 74 patients treated at 4 hospitals between 1990 and 2013 was performed. The median follow-up was 10 years (range: 1-20 years). Risk of tumour recurrence and metastases (unfavourable clinical behaviour) with regard to histology using the Kaplan-Meier and Cox proportional hazards methods. RESULTS: The mean age was 61 years (SD 12.75 years). There were 31 male patients (58%) and 43 female patients (42%). Tumour size ranged from 1 to 30 cm (mean 9.09 cm; SD 6.22 cm). Complete resection (R0) was achieved by minimally invasive thoracoscopic resection in 29% and thoracotomy in 57%; 25% of SFTPs showed histological evidence of malignancy, according to England criteria. Recurrence occurred in 21% and 10% of patients had metastases; 83% of patients with metastases and 39% of patients with recurrence died within 5 years. The median recurrence-free survival for histologically benign SFTP was not reached, compared to 8 years for malignant SFTP. The five-year overall survival rate was 84%. Mitotic rate ≥1/10 HPF, high cellularity, nuclear atypia, Ki-67 level >5% and poorly circumscribed (sessile) growth pattern were associated with poor long-term outcome. CONCLUSIONS: Pathological differentiation of SFTP morphology into pedunculated, well circumscribed and poorly circumscribed (sessile) growth pattern is recommended. Due to the misleading classification into histologically benign and malignant, all unpedunculated SFTP should be classified as potentially aggressive. Lifelong follow-up is mandatory.

Evolution of Pleural Solitary Fibrous Tumors Causing Severe Hypoglycemia after Exceptionally Long Asymptomatic Periods: Report of Two Surgical Cases.

Non-islet cell tumor hypoglycemia (NICTH) is one of the paraneoplastic syndromes manifesting severe hypoglycemia caused by aberrant production of high-molecular-weight insulin-like growth factor 2 (big-IGF2). Two surgical cases of extremely large thoracic solitary fibrous tumors (SFT) with unusual history of NICTH are presented. One case manifested severe hypoglycemia after four years of the first complete surgical resection of the tumor with potential malignant transformation, and the other case showed severe hypoglycemia after ten years of the first detection of the tumor. Meticulous laboratory testing, including serum endocrinological tests and western immunoblotting before and after surgery was performed, and both cases were diagnosed as NICTH. Both patients underwent open thoracic surgery. The patients showed normal glucose and hormone levels immediately after the resection of responsible tumors with elevated blood insulin concentration. SFTs are generally considered benign; however, life-threatening hypoglycemia can happen regardless of treatment. Careful follow-up of the tumor growth is warranted.

Anesthetic management of thoracotomy for massive intrathoracic solitary fibrous tumor of the pleura: a case report.

BACKGROUNDS: Solitary fibrous tumor of the pleura (SFTP) is a rare thoracic tumor and usually asymptomatic. Massive SFTP may affect adjacent organs and tissues including pulmonary vasculature, bronchus and heart. A thoracotomy for massive SFTP is necessary in severe case. Therefore, it is important for anesthesiologists to understand the condition of patients with massive SFTP and develop an appropriate anesthetic management strategy. A 76-year-old woman with massive SFTP presented to our clinical center and was evaluated as requiring thoracotomy. She received multidisciplinary cooperation treatment from the radiology, cardiac, thoracic surgery and anesthetic teams. The perioperative management of anesthesiologists played a crucial role in the great prognosis of this woman. CONCLUSIONS: This case report demonstrates the importance of comprehensive and meticulous perioperative management and provides guidance to the multidisciplinary team on the potential risk and the rational treatment strategy of patients with massive SFTP during the perioperative period.

Our experience with solitary fibrous tumors in the chest area.

The article reports on three patients with a solitary fibrous tumor of the chest. The first patient had a tumor in the area of the dome of the right pleural cavity which was radically resected together with the chest wall around its origin. In the second case, the tumor was attached by a vascular pedicle to the lower lobe of the right lung. This tumor was resected atypically, via thoracotomy, along with a margin of healthy lung tissue at the base of its pedicle. The last patient had a tumor of the lower lobe of the right lung, surrounding the lower pulmonary vein, which did not have a clear margin of healthy lung tissue. This finding required right lower lobectomy via posterolateral thoracotomy. The presented cases describe rare types of tumors in the chest area which at the time of detection often reach large dimensions, necessitating extensive surgical procedures. Due to the biological nature of these tumors, long-term patient follow-up is advisable.

18F-FDG PET/CT characteristics of solitary fibrous tumour of the pleura: single institution experience.

BACKGROUND: To date, published studies have shown that 18F-FDG PET/CT and CT have limited value in differentiating benign and malignant solitary fibrous tumours of the pleura (SFTP). This study aimed to determine whether the metabolic and morphological characteristics of 18F-FDG PET/CT can be a valuable addition to diagnostic tools for SFTPs. METHODS: From January 2016 to November 2021, we performed a retrospective review in 32 SFTPs patients who underwent 18F-FDG PET/CT scan. All the SFTP diagnoses were confirmed by surgical resection or biopsy samples. The metabolic parameters (including SUVmax, SUVmean, MTV, TLG, and SULmax) were obtained from 18F-FDG PET/CT images. RESULTS: Thirty-two patients with SFTP were consecutively identified. The malignant SFTPs have higher Ki-67 expression (P = 0.005). The study observed that tumour heterogeneity without contrast injection (P = 0.001) and intratumor blood vessels (P = 0.047) were morphological features associated with malignant SFTP. Malignant SFTP was more frequently observed with higher SUVmax values (P = 0.001), higher SUVmean values (P = 0.001), higher TLG values (P = 0.006), and higher SULmax values (P < 0.001). For predicting malignant SFTP, the AUC values of SUVmax, SUVmean, TLG, and SULmax obtained by the area under curve analysis were 0.970 (95% CI 0.907-1.000; P = 0.001), 0.874 (95% CI 0.675-1.000; P = 0.009), 0.807 (95% CI 0.654-0.961; P = 0.031), and 0.911 (95% CI 0.747-1.000; P = 0.004), respectively. CONCLUSION: The study showed that metabolic and morphological features were useful for distinguishing malignant from benign SFTPs.

68Ga-DOTATOC PET/CT in Pleural Solitary Fibrous Tumors.

ABSTRACT: Solitary fibrous tumor of the pleura (SFTP) is a rare mesenchymal neoplasm. Preoperative diagnosis is usually difficult and based on radiological findings only. We report the imaging results observed in 5 patients with SFTP (2 malignant) obtained by 68Ga-DOTATOC PET/CT. At qualitative analysis, all tumors showed uptake of 68Ga-DOTATOC. Mean tumor SUVmax was 9.9 ± 5.7. The expression of SST2 (somatostatin receptors subtype 2) was confirmed by immunohistochemistry in 2 tumor samples, and by gene amplification of SST2 mRNA in all cases. These data suggest a diagnostic role of radioreceptor PET/CT in SFTP, and open novel potential treatment options in unresectable/metastatic disease.

Case report: uniportal video-assisted thoracoscopic resection of a solitary fibrous tumor preoperatively predicted visceral pleura origin using dynamic chest radiography.

BACKGROUND: Dynamic chest radiography (DCR) is a flat-panel detector (FPD)-based functional X-ray imaging, which is performed as an additional examination in chest radiography. DCR provides objective and quantifiable information, such as diaphragm movement, pulmonary ventilation and circulation, and is reasonable for detecting tumor invasion or adhesion. CASE PRESENTATION: We present a case of Solitary Fibrous Tumor of Pleura (SFTP), preoperatively predicted visceral pleura origin using Dynamic chest radiography (DCR) and surgically resected through single-access (uniportal) video-assisted thoracoscopic surgery (UVATS). CONCLUSIONS: UVATS may be a suitable surgical option for pedunculated SFTPs. Dynamic chest radiography provides information, such as tumor invasion or adhesion and helpful for predicting origin of the tumor.

Molecular characterization of localized pleural mesothelioma.

Localized pleural mesothelioma is a rare solitary circumscribed pleural tumor that is microscopically similar to diffuse malignant pleural mesothelioma. However, the molecular characteristics and nosologic relationship with its diffuse counterpart remain unknown. In a consecutive cohort of 1110 patients with pleural mesotheliomas diagnosed in 2005-2018, we identified six (0.5%) patients diagnosed with localized pleural mesotheliomas. We gathered clinical history, evaluated the histopathology, and in select cases performed karyotypic analysis and targeted next-generation sequencing. The cohort included three women and three men (median age 63; range 28-76), often presenting incidentally during radiologic evaluation for unrelated conditions. Neoadjuvant chemotherapy was administered in two patients. All tumors (median size 5.0 cm; range 2.7-13.5 cm) demonstrated gross circumscription (with microscopic invasion into lung, soft tissue, and/or rib in four cases), mesothelioma histology (four biphasic and two epithelioid types), and mesothelial immunophenotype. Of four patients with at least 6-month follow-up, three were alive (up to 8.9 years). Genomic characterization identified several subgroups: (1) BAP1 mutations with deletions of CDKN2A and NF2 in two tumors; (2) TRAF7 mutations in two tumors, including one harboring trisomies of chromosomes 3, 5, 7, and X; and (3) genomic near-haploidization, characterized by extensive loss of heterozygosity sparing chromosomes 5 and 7. Localized pleural mesotheliomas appear genetically heterogeneous and include BAP1-mutated, TRAF7-mutated, and near-haploid subgroups. While the BAP1-mutated subgroup is similar to diffuse malignant pleural mesotheliomas, the TRAF7-mutated subgroup overlaps genetically with adenomatoid tumors and well-differentiated papillary mesotheliomas, in which recurrent TRAF7 mutations have been described. Genomic near-haploidization, identified recently in a subset of diffuse malignant pleural mesotheliomas, suggests a novel mechanism in the pathogenesis of both localized pleural mesothelioma and diffuse malignant pleural mesothelioma. Our findings describe distinctive genetic features of localized pleural mesothelioma, with both similarities to and differences from diffuse malignant pleural mesothelioma.

Localized malignant mesothelioma, an unusual and poorly characterized neoplasm of serosal origin: best current evidence from the literature and the International Mesothelioma Panel.

Localized malignant mesotheliomas (LMM) is an uncommon and poorly recognized neoplasm. Its pathologic diagnosis is often surprising in patients with serosal/subserosal based localized tumors that are clinically suspicious for metastatic lesions or primary sarcomas. Once a tumor is diagnosed as "mesothelioma", LMM is often mistaken for diffuse malignant mesothelioma (DMM). Best currently available evidence about LMM was collected from the literature and cases diagnosed by members of the International Mesothelioma Panel (IMP). One hundred and one (101) LMM have been reported in the English literature. Patients had localized tumors with identical histopathologic features to DMM. Patients ranged in age from 6 to 82 years; 75% were men. Most (82%) of the tumors were intrathoracic. Others presented as intrahepatic, mesenteric, gastric, pancreatic, umbilical, splenic, and abdominal wall lesions. Tumors varied in size from 0.6 to 15 cm. Most patients underwent surgical resection and/or chemotherapy or radiation therapy. Median survival in a subset of patients was 29 months. Seventy two additional LMM from IMP institutions ranged in age from 28 to 95 years; 58.3% were men. Sixty tumors (83.3%) were intrathoracic, others presented in intraabdominal sites. Tumors varied in size from 1.2 to 19 cm. Median survival for 51 cases was 134 months. Best evidence was used to formulate guidelines for the diagnosis of LMM. It is important to distinguish LMM from DMM as their treatment and prognosis is different. A multidisciplinary approach is needed for the diagnosis of LMM as it shows identical histopathology and immunophenotype to DMM.

Localized biphasic malignant peritoneal mesothelioma presenting as a rectal tumor.

An 84-year-old male presented with bloody stool. On digital rectal examination, a large and firm tumor was palpated in the anterior wall of the rectum at 2 cm from the anal verge. The colonoscopy revealed an ulcerated mass with smooth margins in the anterior wall of the rectum. Enhanced computed tomography showed a huge tumor in the pelvis, invading rectum, urinary bladder and the prostate, with signs of splenic and peritoneal metastases. Findings from an endoscopic biopsy and endoscopic ultrasound-guided fine needle aspiration suggested spindle cell carcinoma. We tentatively diagnosed as spindle cell carcinoma of the rectum and administered panitumumab as palliative chemotherapy. He eventually died at 4 months after the first visit to our institution. The autopsy findings resulted in the confirmed diagnosis as biphasic malignant peritoneal mesothelioma. There are only four previous reports on malignant peritoneal mesothelioma presenting as a colorectal tumor. Although rare, malignant peritoneal mesothelioma should be considered in differential diagnosis of colorectal tumors.

Surgical recurrence of solitary fibrous tumor of the pleura treated with microwave (MW) thermoablation: A case report.

Solitary fibrous tumor (SFT) of the pleura is a rare neoplasm which is challenging for clinicians to treat and radiologists to diagnose. Herein, we report a case of recurrence of SFT of the pleura in a 77-year-old patient which was diagnosed and surgically treated on the first occasion in 2005. The patient had a recurrence in 2016 which was treated and then six months later, he again experienced chest pain and a further local recurrence was found. Taking into consideration the age and comorbidities of the patient, CT-guided percutaneous microwave-thermal ablation was preferrable to surgery and a safe and highly effective local ablative technique with few side-effects.