Solitary Fibrous Tumors of Chest: Another Look with the Oncologic Perspective

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.

Solitary Fibrous Tumours of the Orbit - Clinical Pathology, Therapy and Prognosis

BACKGROUND

Solitary fibrous tumours are rare. The aim of this study is to describe the clinical features, therapy and outcome of affected patients and to identify factors associated with recurrence.

METHODS

Retrospective study of a cohort of 20 patients who underwent surgery for orbital solitary fibrous tumour at the University Department of Oral and Maxillofacial Surgery between 2002 and 2023. Demographic, clinical, and therapeutic data as well as tumour follow-up results were collected. Tumour volume and molecular genetic mutations were retrospectively determined.

RESULTS

The median patient age was 49.5 years at initial surgery. The left orbit was affected in 65% of cases. The most common clinical symptom was proptosis (80%). This was reported with a mean lateral difference of 3.9 mm (range: 1 - 10 mm). The tumours were localised predominantly in the intra- and extraconal space, craniolateral quadrant and middle third. The median tumour volume was 7.66 cm³ (range 2.15 - 12.57 cm³). In all patients, the diagnosis was made by pathological examination. All tumours investigated showed a NAB2-STAT6 mutation. The most frequently detected mutation was the fusion NAB2 exon 4 - STAT6 exon 2. All patients were initially managed with frontolateral orbitotomy. Incomplete resection (R1-status) occurred in 35% (n = 7). The recurrence rate was 25% (n = 5), with a median disease-free interval of 45.5 months (range 23 - 130). 80% (n = 4) of recurrences were initially R1-resected.

CONCLUSION

Orbital solitary fibrous tumours are rare tumours and are clinically manifested by signs of displacement of orbital structures. Diagnosis is made by histology and immunohistochemistry and can be proven with the molecular genetic detection of the NAB2-STAT6 mutation. The therapy of choice is complete surgical resection. R1-resection is more likely in the intraconal location as well as in location in the posterior third of the orbit - due to difficult surgical accessibility. The greatest risk factor for the development of recurrence is incomplete surgical excision. Late recurrences are possible, which is why a long-term connection to a specialised clinic is necessary.

Cytology of malignant pleural mesothelioma: Diagnostic criteria, WHO classification updates, and immunohistochemical staining markers diagnostic value

Malignant pleural mesothelioma (MPM) is a rare but aggressive malignancy with a poor prognosis. Because of this tumor rarity and overlapping histologic features with other malignancy types, the histopathological findings and diagnostic immunohistochemical workup are essential in establishing the final diagnosis of MPMs. We aimed to review the diagnostic criteria, WHO tumor classification updates, and immunohistochemical staining markers diagnostic value to achieve an appropriate clinical diagnosis.

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.

Focal PSMA-Positive Pleural Lesion in a Patient With Stage II Prostate Carcinoma

ABSTRACT

A 70-year-old man with histopathologically proven prostate carcinoma (Gleason, 5 + 5; prostate-specific antigen level, 6.2 μg/mL) was referred for an 18F-PSMA-1007 PET/CT scan. The scan revealed bilateral PSMA uptake in the prostate, representing the primary tumor, but no evidence of PSMA-positive lymph nodes. However, a left-sided ventral pleural thickening showed focal PSMA uptake. Lesion biopsy showed no signs of malignancy, and prostatectomy was performed. The 1-year follow-up CT thorax showed growth of approximately 20% of the pleural lesion. Subsequently, video-assisted thoracic surgery of the lesion was performed. Histopathology showed a solitary fibrous tumor, a rare mesenchymal tumor.

Solitary fibrous tumors: Clinical and imaging features from head to toe

Solitary fibrous tumors (SFTs) are rare fibroblastic mesenchymal tumors that are usually benign with variable malignant potential. They can develop in any organ due to their spindle cell origin. The exact etiology of solitary fibrous tumors is unknown. The majority of SFTs are benign with 10-30% of them exhibiting aggressive and malignant features. The aggressiveness of this type of tumor is not associated with its histological features, which makes surgical resection the treatment of choice. We will review the clinical and radiological features and possible differential diagnoses of SFTs according to their anatomical sites following the World Health Organization 2020 classification.

Doege-Potter syndrome: a systematic review of the literature and case presentation of a rare pelvic malignant solitary fibrous tumour

Solitary fibrous tumours (SFTs) are a rare mesenchymal neoplasm with an incidence of 2.8 per 100 000 of which only 1% occur in the female genital tract. Doege-Potter syndrome is a paraneoplastic phenomenon associated with approximately 5%-10% of SFTs and is characterised by non-islet cell hypoglycaemia due to tumour production of low molecular weight insulin-like growth factor-II. We present the fourth confirmed case of female pelvic SFT with Doege-Potter syndrome and a literature review.

Locally advanced malignant solitary fibrous tumour successfully treated with conversion chemotherapy, operation and postoperative radiotherapy: a case report

Preoperative diagnosis of solitary fibrous tumour (SFT) may not provide a complete tumour picture and may be inaccurate. There is no standard treatment for locally advanced or metastasised malignant SFT (MSFT). Here, the case of a 17-year-old male patient with final pathology diagnosis of MSFT is reported. Preoperative biopsy pathology results suggested an Ewing sarcoma that was positive for CD99 antigen, vimentin, friend leukaemia integration 1 transcription factor, apoptosis regulator Bcl-2, and synaptophysin; and negative for CD34 antigen, S-100 protein (S-100), smooth muscle antigen, cytokeratin, and Wilms tumour 1 associated protein. The Ki67 positive rate was 8%, so the patient initially received eight cycles of conversion chemotherapy (vincristine, etoposide, ifosfamide and pirarubicin for one cycle, and vincristine, doxorubicin, and cyclophosphamide/ifosfamide and etoposide for 7 cycles in total). The tumour shrunk significantly and was surgically removed. The final pathology diagnosis was MSFT that was positive for CD99 and signal transducer and activator of transcription 6, and negative for CD34, tumour protein 63, S-100, desmin, and epithelial membrane antigen. Fluorescence in situ hybridization showed no gene translocation in EWS RNA binding protein 1, SS18 subunit of BAF chromatin remodelling complex or FUS RNA binding protein. The patient finally accepted adjuvant radiotherapy of 5600 cGy. Disease-free survival has been > 1 year, with no recurrence or metastasis detected to date. MSFT is rare and treatment for locally advanced or metastatic MSFT remains controversial. The efficacy of the present therapeutic strategy requires further research.

[Solitary fibrous tumor of pleura (symptoms, diagnosis, treatment)]

OBJECTIVE

Optimization of diagnosis and treatment of patients with solitary fibrous tumor of pleura, analysis of overall survival and disease-free survival, predictors of recurrence.

MATERIAL AND METHODS

There were 66 patients with solitary fibrous tumor of pleura (26 men and 40 women) aged 57.6 years (range 26-80 years). Asymptomatic course was found in 29 (44%) patients, various symptoms - in 37 (56%) patients. Thoracotomy was applied in 36 patients, thoracoscopy - in 30 patients. Immunohistochemical examination included analysis of definition of Stat6 expression.

RESULTS

Benign variant of SFT was diagnosed in 50 (75.7%) patients, malignant variant - in 16 (24.3%) patients. STAT6 expression was observed in all cases. Postoperative morbidity was 9%, mortality - 1.6%. Recurrence was diagnosed in 2 (4%) patients with benign variant of disease and in 5 (31.2%) patients with malignant variant (2 of them died from progression of disease). Progression-free survival was 89.4%, overall survival - 95.4%. Predictors of recurrence are tumor dimension over 10 cm, necrosis and/or hemorrhagic component of tumor, mitotic count of at least four per 10 high-power fields.

CONCLUSION. S

Olitary fibrous tumor of pleura is a rare mesenchymal fibroblastic neoplasm growing from submesothelial layer. Differential and preoperative morphological diagnosis of SFT is difficult and demands a special immunohistochemical examination with analysis of Stat 6 expression. Surgery is preferred for tumor de novo and recurrent neoplasm.

Single Solitary Fibrous Tumor Brain Metastasis in a Patient with Simultaneous Adenocarcinoma of the Lung: Case Report and Review of the Literature

We present a unique case of a patient simultaneously diagnosed with solitary fibrous tumor (SFT) and unrelated adenocarcinoma of the lung, both proven with separate pathology. It was subsequently found that the SFT had metastasized to the brain by additional pathology, and not the predicted adenocarcinoma. SFTs are a rare mesenchymal neoplasm that accounts for less than 2% of all reported soft tissue tumors. SFTs most commonly arise in the thoracic cavity, but are frequently found in various locations throughout the body, and rarely metastasize to the brain. This case highlights that rare neoplasms, such as SFT, should not be ruled out as a potential cause of metastasis. Due to the rarity of this clinical situation, we also provide a review and discussion of previously reported SFT cases and the use of postoperative radiation therapy. The optimal treatment for individual patients remains unclear in this unique situation. Surgical resection followed by adjuvant Gamma Knife radiation therapy to the surgical bed appears to be a safe option for local treatment of SFT in select patients. Further studies are needed of this rare clinical situation in order to better understand and optimize future treatments for patients with SFT and metastasis to the brain.

Massive malignant solitary fibrous tumor of the diaphragm: A case report

INTRODUCTION

Malignant solitary fibrous tumor (MSFT) of the diaphragm is extremely rare, and to the best of our knowledge, only three cases have been reported in the past two decades. In all these cases, the diaphragms were usually reconstructed with artificial diaphragm patch because of the extensive resection.

PATIENT CONCERNS

We reported a male patient with complaints of dyspnea, chest pain and massive pleural effusion in the left chest detected by chest X-ray. A huge mass of 20 × 20 cm was seen in the left lower chest in the computed tomography (CT) scan.

DIAGNOSIS

The diagnosis of MSFT originating in the diaphragm was made by post-operative immunohistochemical examination.

INTERVENTIONS

After draining 4000 ml of pleural effusion by Pleurx catheter to relieve the pressure symptom, the patient underwent en-block resection by left posterolateral thoracotomy. A pedicle tumor originating in the left diaphragm was found, which was smooth, lobular, did not invade surrounding tissues or organs, and received blood supply from the left phrenic vessels. The diaphragm was successfully sutured without tension and did not require artificial reconstruction as the defect was small.

OUTCOMES

After 2 months follow-up, the left lung was restored to normalcy, and no pleural effusion or new occupying neoplasm was found in follow-up CT.

Solitary fibrous tumour of the sigmoid colon mesentery

Solitary fibrous tumours (SFTs) are rare tumours arising from mesenchymal tissues. Despite of their more frequent occurrence in the pleura, SFT can present anywhere in the body. Only a few cases have been described arising from the mesentery. Most tumours have a benign nature; however, up to 20% of them can spread, most commonly to liver, lung and bone. Surgical excision including all surrounding tissues remains the treatment of choice; however, there is no consensus regarding the need for adjuvant therapies. We present a 79-year-old man with abdominal pain who was found to have a SFT in the mesentery of the sigmoid colon, treated with en bloc resection. A multidisciplinary team including surgeons, medical and radiation oncologists is recommended in the care of these patients.