Extending the Indications of 5-Aminolevulinic Acid for Fluorescence-Guided Surgery for Different Central Nervous System Tumors: A Series of 255 Cases in Latin America

Introduction Fluorescence guidance with 5-aminolevulinic acid (5-ALA) is a safe and reliable tool in total gross resection of intracranial tumors, especially malignant gliomas and cases of metastasis. In the present retrospective study, we have analyzed 5-ALA-induced fluorescence findings in different central nervous system (CNS) lesions to expand the indications of its use in differential diagnoses. Objectives To describe the indications and results of 5-ALA fluorescence in a series of 255 cases. Methods In 255 consecutive cases, we recorded age, gender, intraoperative 5-ALA fluorescence tumor response, and 5-ALA postresection status, as well the complications related to the method. Postresection was classified as ‘5-ALA free’ or ‘5-ALA residual’. The diagnosis of histopathological tumor was established according to the current classification of the World Health Organization (WHO). Results There were 195 (76.4%) 5-ALA positive cases, 124 (63.5%) of whom underwent the ‘5-ALA free’ resection. The findings in the positive cases were: 135 gliomas of all grades; 19 meningiomas; 4 hemangioblastomas; 1 solitary fibrous tumor; 27 metastases; 2 diffuse large B cell lymphomas; 2 cases of radionecrosis; 1 inflammatory disease; 2 cases of gliosis; 1 cysticercosis; and 1 immunoglobulin G4-related disease. Conclusion Fluorescence with 5-ALA can be observed in lesions other than malignant gliomas or metastases, including meningiomas, hemangioblastomas, pilocytic astrocytomas, and lymphomas. Although there is need for further evidence for the use of 5-ALA beyond high-grade gliomas, it may be a safe and reliable tool to improve resection in positive tumors or to guide the histopathologic analysis in biopsies.

Case Report: Molecular Characterization of Aggressive Malignant Retroperitoneal Solitary Fibrous Tumor: A Case Study

Solitary fibrous tumors (SFT) are mesenchymal neoplasms with a favorable prognosis usually originating from the visceral pleura. Rarely, they may occur at various extrapleural sites and show malignant behavior coupled with dedifferentiation. NAB2-STAT6 fusion gene and STAT6 nuclear expression are biomarkers for diagnosis of SFT in addition to CD34, Bcl-2, and CD99. Furthermore, several reports have shown specific NAB2-STAT6 fusion variants and loss of STAT6 protein expression are associated with malignancy. We report a rare case of retroperitoneal SFT which rapidly progressed to death within 35 days after admission. Autopsy found a primary tumor containing both benign and malignant histologies, with multiple metastatic sites similar to the malignant, dedifferentiated tumor. STAT6 was detected in the primary differentiated tumor but not in the primary dedifferentiated tumor or lung/liver metastases. However, the NAB2-STAT6 fusion gene (NAB2ex6/STAT6ex16 variant) was detected in the primary tumor and lung/liver metastases. Intriguingly, fusion gene expression at the transcriptional level was downregulated in the dedifferentiated tumors compared to the differentiated tumor. We further performed target DNA sequencing and found gene mutations in TP53, FLT3, and AR in the dedifferentiated tumors, with TP53 mutations especially found among them. We demonstrate that downregulation of NAB2-STAT6 fusion gene at the transcriptional level is associated with malignant SFT for the first time. Moreover, the present study supports the idea that TP53 mutations promote malignancy in SFTs.

Postoperative progression of intracranial grade II–III solitary fibrous tumor/hemangiopericytoma: predictive value of preoperative magnetic resonance imaging semantic features

Background Preoperative prediction of postoperative tumor progression of intracranial grade II–III hemangiopericytoma is the basis for clinical treatment decisions. Purpose To use preoperative magnetic resonance imaging (MRI) semantic features for predicting postoperative tumor progression in patients with intracranial grade II–III solitary fibrous tumor/hemangiopericytoma (SFT/HPC). Material and Methods We retrospectively analyzed the preoperative MRI data of 42 patients with intracranial grade II–III SFT/HPC, as confirmed by surgical resection and pathology in our hospital from October 2010 to October 2017, who were followed up for evaluation of recurrence, metastasis, or death. We applied strict inclusion and exclusion criteria and finally included 37 patients. The follow-up time was in the range of 8–120 months (mean = 57.1 months). Results Single-factor survival analysis revealed that tumor grade (log-rank, P = 0.024), broad-based tumor attachment to the dura mater (log-rank, P = 0.009), a blurred tumor-brain interface (log-rank, P = 0.008), skull invasion (log-rank, P = 0.002), and the absence of postoperative radiotherapy (log-rank, P = 0.006) predicted postoperative intracranial SFT/HPC progression. Multivariate survival analysis revealed that tumor grade ( P = 0.009; hazard ratio [HR] = 11.42; 95% confidence interval [CI] = 1.832–71.150), skull invasion ( P = 0.014; HR = 5.72; 95% CI = 1.421–22.984), and the absence of postoperative radiotherapy ( P = 0.001; HR = 0.05; 95% CI = 0.008–0.315) were independent predictors of postoperative intracranial SFT/HPC progression. Conclusion Broad-based tumor attachment to the dura mater, skull invasion, and blurring of the tumor–brain interface can predict postoperative intracranial SFT/HPC progression.

Primary solitary fibrous tumor of the thyroid gland: A review starting from a case report

Primary solitary fibrous tumor (SFT) of the thyroid gland is a rare mesenchymal tumor with fibroblastic differentiation, ramified, thin-walled, enlarged (staghorn) vessels and specific NAB2-STAT6 gene fusion, which is more commonly found in pleura and peritoneum. This neoplasm can be located in a variety of anatomical sites outside pleura and peritoneum including bone, visceral organs and soft tissues, head and neck examples representing only 10-15% of the extra-pleural and extra-peritoneal tumors. Diagnosing this entity can be difficult, especially in thyroid gland, mainly because of the rarity of this neoplasm, but presence of characteristic microscopic features together with positivity for STAT6 and CD34 can confirm the diagnosis and exclude other differential diagnosis. Information about the diagnosis and treatment options of thyroid SFTs is limited but almost all primary thyroid SFTs have a good prognosis and indolent clinical course. Clinical surveillance is still necessary because some SFTs can be aggressive. Raising awareness regarding extra-pleural and extra-peritoneal location of this tumor in endocrine organs can help to better manage these patients. We report the case of a 34-year-old female with primary SFT of the thyroid gland. Additionally, we review the literature for the main clinical, paraclinical and pathological features of this neoplasm.

Primary Sclerosing Epithelioid Fibrosarcoma of the Kidney: A Case Report and Review of the Literature

Sclerosing epithelioid fibrosarcoma (SEF) is a rare variant of fibrosarcoma. We report one case of primary kidney SEF occurring in a 38-year-old man. Microscopically, epithelioid neoplastic cells are mainly arranged in cords and nests embedded in the dense sclerosing stroma. Diffuse immunohistochemical staining for MUC4 in neoplastic cells and the presence of the EWSR1 gene split by fluorescence in situ hybridization (FISH) analysis confirmed the histological diagnosis. Primary kidney SEF is extremely rare, the differential diagnosis strategy broadly includes a series of tumors with epithelioid morphology and sclerosing matrix, mainly including sclerosing variants of clear cell sarcoma of the kidney (CCSK), renal synovial sarcoma (SS), renal solitary fibrous tumor (SFT), metanephric stromal tumor (MST), sclerosing perivascular epithelioid cell tumor (PEComa), and carcinomas, and immunohistochemical expression of MUC4 and evidence of the EWSR1 gene split are helpful in making a definite diagnosis.

Clinical Features, Management and Prognostic Factors of Intracranial Solitary Fibrous Tumor

Purpose Due to low incidence and the constantly changing diagnostic and classification criteria, the clinical features, management and prognostic factors of intracranial solitary fibrous tumor (ISFT) remain unclear and were thus analyzed in this study. Methods A total of 38 patients who were diagnosed as ISFT in our institution were enrolled in this study. Patient data including age, gender, clinical presentation, histopathological features, immunohistochemistry staining, tumor location, tumor size, treatment methods, and prognosis were extracted and retrospectively analyzed. Results The median age at diagnosis was 45.5 years (range 28-66 years) and the male to female ratio was 1:1.53 in our series. The 3-, 5-, and 10-year progression-free survival rate was 82.2%, 62.8%, and 21.4%, respectively; and the 3-, 5-, and 10-year overall survival rate was 97.1%, 86.9% and 64.2%, respectively. Patients with high WHO grade (grade III) ISFTs had impaired PFS (p<0.05) and OS (p<0.01). Subtotal resection (STR) was associated with shorter PFS and OS (p<0.001, respectively). Postoperative radiotherapy (PORT) significantly improved PFS but not OS in patients with WHO grade III ISFTs (P=0.025). The PFS of patients with STR+PORT was improved compared with those who received STR alone, although not significant. Moreover, CD34-negative immunostaining and high Ki-67 index (>10%) were associated with impaired PFS in ISFTs.Conclusion Our study provides evidence that high tumor grade, subtotal tumor resection, CD34 negative immunostaining and high Ki-67 index (>10%) were independent predictors for poor prognosis of ISFTs. PORT should be recommended for patients with high grade ISFTs or STR.

Solitary Fibrous Tumors Arising from Bilateral Ovaries: A Case Report and Review of the literature

Background: A solitary fibrous tumor (SFT) is a distinct mesenchymal neoplasm. It was originally described as a tumor localized to the pleura but was later reported in several other anatomic sites and exhibited a wide spectrum of histological features. Owing to its rarity, the diagnosis of extrapleural SFT is challenging and requires an integrated approach comprising specific clinical, imaging, histological, and immunohistochemical findings. Case presentation: Herein, we report the imaging findings of a rare case of SFT arising from bilateral ovaries confirmed by surgical excision and histological examination. No adjuvant radiotherapy or chemotherapy was given to the patient, and she was disease-free with no evidence of recurrence or metastasis at the 96-month postoperative follow-up. Although it mostly follows a favorable course, SFT is notoriously difficult for prognostication because of its propensity for late relapse or even metastases in 10–39% of cases. Conclusion: Close follow-up is recommended because of the limited information on its long-term behavior.