Solitary fibrous tumor: A center's experience and an overview of the symptomatology, the diagnostic and therapeutic procedures of this rare tumor

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.

Recurrent Hypoglycemia Due to a Massive Abdominal Tumor in a Nonagenarian: A Case Report and Review of the Literature

Patient: Male, 94-year-old

Final Diagnosis: Doege Potter syndrome • solitary fibrous tumor

Symptoms: Falls • hypoglycemia

Medication: —

Clinical Procedure: —

Specialty: Geriatrics • Medicine, General and Internal

Doege-Potter Syndrome and Hypoglycemia associated with Solitary Fibrous Tumor of the Pleura: Two Case Reports

Solitary fibrous tumors of the pleura (SFTP) are rare mesenchymal neoplasms that originate from mesenchymal growth in the pleura, tend to be single tumors, usually have an indolent course and show nonspecific symptoms. SFTP can be often diagnosed from an incidental finding of a single mass in the thorax and should be confirmed by biopsy and immunohistochemistry. A minority of cases may present Doege–Potter syndrome (DPS, episodes of refractory hypoglycemia) associated with production of insulin-like growth factor 2 (IGF-2). Both SFTP and DPS are rare occurrences with less than 2000 cases reported worldwide. The curative treatment is tumor resection. Two cases of patients with DPS caused by SFTP are presented below.

Solitary fibrous tumor of the pleura with Doege-Potter syndrome: Second recurrence in a 93-year-old female

Solitary fibrous tumors are rare mesenchymal tumors most commonly arising from the pleura. When associated with paraneoplastic syndrome of hypoglycemia caused by the secretion of a high-molecular-weight form of insulin-like growth factor II, it is referred to as the Doege–Potter syndrome. Surgery with complete tumor resection is the only curative treatment. We present here the case of a 93-year-old female diagnosed with a Doege–Potter syndrome who underwent three repetitive surgical resections of recurrent solitary fibrous tumor.

Efficacy of bevacizumab and temozolomide therapy in locally advanced, recurrent, and metastatic malignant solitary fibrous tumour: A population-based analysis

Background

Patients with locally advanced, recurrent or metastatic solitary fibrous tumour are often treated with bevacizumab and temozolomide based on the clinical efficacy reported in a case series of 14 patients. Given the rarity of solitary fibrous tumour, large trials are not feasible. We report the efficacy of this regimen based on a population-based analysis.

Methods

This was a population-based retrospective, multi-centre analysis using patient data from a provincial cancer registry and treatment database. Cases from June 2006 through October 2016 were identified for patients receiving bevacizumab and temozolomide for locally advanced, recurrent or metastatic solitary fibrous tumour or hemangiopericytoma, which is sometimes used to describe tumours arising from the meninges. The primary outcome was overall response rate. Secondary outcomes included time to response, progression free survival and overall survival estimated using the Kaplan–Meier method.

Results

Fourteen patients were identified: median age 59 (range 44–70), male 78.6%. Diagnoses were solitary fibrous tumour in 10 (71.4%) and hemangiopericytoma in four (28.6%), with metastatic disease in 10 (72.7%) patients. The most common primary sites were meninges in four (28.6%) and pelvis in three (21.4%) patients. The median follow-up was 15.5 months, with median treatment of four months. Overall response rate was 21.4% (no complete response, 3 partial response), with median time to response of four months. Median progression free survival, six-month progression free survival and overall survival were 17 months, 65.0%, and 45 months, respectively.

Conclusions

Efficacy of bevacizumab and temozolomide in solitary fibrous tumour appeared to be similar to that previously reported. Our findings confirmed that bevacizumab and temozolomide is an effective and tolerated treatment for this patient population.

Doege-potter syndrome: a report of a histologically benign but clinically malignant case

Background

Solitary fibrous tumors of the pleura (SFTPs) are relatively rare tumors that originate from mesenchymal cells of submesothelial tissue of the pleura. Most patients with SFTPs are asymptomatic; however, pleuritic chest pain, cough, and dyspnea can develop. If hypoglycemia is associated with a solitary fibrous tumor, it is referred to as the Doege-Potter syndrome.

Case presentation

A 70-year-old man had visited our hospital with a chief complaint of dyspnea, and he was diagnosed as having a solitary fibrous tumor. A few years later, he developed hypoglycemia, and he underwent excision of the mass.

Conclusion

Occasionally, SFTPs induce several paraneoplastic events, such as hypertrophic osteoarthropathy. We described here a patient with an SFTP with Doege-Potter syndrome who was successfully treated with complete resection. Although lesions can be histologically benign, they can clinically present with malignant features.