Fibrosarcomas of the Paranasal Sinuses: A Systematic Review

Fibrosarcomas are rare, malignant neoplasms of mesenchymal origin. Fibrosarcomas appear to be sporadic, but cases of fibrosarcomas secondary to radiation of nasopharyngeal carcinomas have been reported. Paranasal sinus fibrosarcomas (PNFS) are even rarer with few cases being reported since the 1950s. There have been several retrospective cohort studies examining PNFS; however, to our knowledge, no comprehensive review exists. This review aims to summarize the findings of all published cases of PNFS from the 1950s to the 2020s. We hope that a comprehensive review will assist in accurate and early diagnoses of PNFS, and help guide treatment as early treatment is associated with a favorable prognosis.This systematic review reports results following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A search was conducted on PubMed, Embase, and Cochrane Library. Studies were screened using established inclusion/exclusion criteria. A total of 26 studies were included for data extraction, and relevant data were collected and analyzed.In our study, the most common study type was case reports (n = 19). The most common presentation for PNFS included male gender (n = 17) with maxillary sinus (n = 57) involvement. Patients commonly presented with complaints of nasal obstruction (n = 15), epistaxis (n = 11), and facial fullness/pain (n = 9). Surgical resection was the mainstay treatment, with the use of chemotherapy or radiation depending on surgical margins and resectability. The diagnosis was commonly made with histological analysis. This review of the literature provides a summary and reference of important presenting factors, elements of diagnosis, and treatment options regarding PNFS to help bring awareness and guide the treatment of such a rare disease. Moving forward, there is a greater need for larger standardized studies that can further complement our findings, as well as more consistent reporting of cases.


Introduction And Background
Fibrosarcomas are rare, malignant neoplasms of mesenchymal origin that comprise 7-10% of all head and neck sarcomas [1]. Fibrosarcoma appears to be sporadic, but cases of fibrosarcoma secondary to radiation of nasopharyngeal carcinomas have been reported [2]. Paranasal sinus fibrosarcomas (PNFS) are even rarer with few cases being reported since the 1950s. There have been several retrospective cohort studies examining PNFS; however, to our knowledge, no complete review exists [3,4].
As with other nasal cavity and paranasal sinus pathologies, PNFS often presents with unilateral nasal obstruction and epistaxis, sometimes being mistaken as a papilloma [1]. Previous reports have found associations with age and gender but reports vary [4,5]. Final staging and diagnosis are based on imaging, histopathology, and immunohistochemistry, with a characteristic herringbone arrangement of fibroblasts being pathognomonic [6].
PNFS is associated with a high risk of local recurrence and a low risk of distant metastasis [3]. Due to this association, PNFS are often treated with local excision with large margins with or without radiotherapy [1]. The extent of resection is also dependent upon the presence or absence of bone invasion. The anatomical site seems to correlate with the prognosis of sarcomas in general, with lesions of extremities having a more favorable outcome than central locations such as the pelvis, head/neck, and rib [2,7]. Prognosis according to paranasal sinus location has not been defined.
This review aims to summarize the findings of all published cases of PNFS from the 1950s to the 2020s. A total of 109 cases from 26 articles were collected from PubMed, Embase, and Cochrane. This review covers study characteristics, presentation of symptoms, location of the tumor, pathological findings, diagnosis, treatment, and complications. We hope that a comprehensive review will assist in accurate and early diagnoses of PNFS, as early treatment is associated with a favorable prognosis.

Review Methods
This systematic review reports results following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines [8]. A search was conducted on PubMed, Embase, and Cochrane Library on September 25th, 2020 (Appendix). The objective of the study and inclusion/exclusion criteria were documented prior to initiating the study. Figure 1 demonstrates the search strategy for this review. All studies were assigned levels of evidence according to the Oxford Centre for Evidence-Based Medicine (OCEBM) [9].

Study Selection
Titles and abstracts of studies retrieved were screened for inclusion by two independent reviewers, and a separate third reviewer resolved all conflicts. The full text of included studies was subsequently reviewed. Studies were screened for inclusion using the Medical Subject Heading (MeSH) terms related to fibrosarcoma of the paranasal sinuses. Inclusion criteria included studies of patients with fibrosarcomas in the paranasal regions. Articles that were non-English, non-human studies, review articles, books, and studies unrelated to fibrosarcoma of the paranasal sinuses were excluded. Twenty-six studies were included for data extraction.

Data Extraction
Data extraction was conducted using a Microsoft Excel spreadsheet (Microsoft Corporation, Redmond, WA). Patient demographics were collected, such as age and gender. Study characteristics, including study type, year of publication, and authorship, and the number of patients in the study were collected. Clinical data regarding presenting symptoms, location of the fibrosarcoma, use of chemotherapy and/or radiation, surgical interventions, and histopathology characteristics were gathered. Comments regarding patient outcomes were collected including survival and mortality. The collected data were then organized into graphical figures and tables.

General Overview
A preliminary search yielded 632 articles after duplicates were removed, with 26 ultimately meeting inclusion criteria and were included in our study. No previous systematic reviews related to fibrosarcomas of the paranasal sinuses were identified. Articles ranged in publication date from 1952 to 2019. A total of 109 patients were derived from 19 case reports, four case series, and three retrospective cohort studies. All included studies are listed in Table 1.

Title
Author

Type of Treatment Analysis
The aggregate data for treatment and outcome of patients with fibrosarcoma can be found in Table 3. There were 109 patient cases that were analyzed in regards to the type of treatment they received. In total, 46% (n = 49) of patients underwent only surgical management. In total, 39% (n = 41) of patients received radiation as a form of treatment, 10% (n = 11) of patients underwent chemotherapy and no radiation, and 5% (n = 5) of patients received both chemotherapy and radiation. Out of 52 patient cases that reported mortality information within one year of treatment, 35% (n = 18) of cases reported patient death within one year. The individual surgical approaches are described in Table 3.

Discussion
To the best of our knowledge, no comprehensive review of PNFS exists. Consequently, a consensus on PNFS demographics, presentation, diagnosis, treatment, and prognosis has not been found. This is significant because only a few cases of PNFS have been reported since the 1950s and an early diagnosis is associated with a more favorable outcome. We include our recommendations below.

Demographics and Symptoms
Cancer of the paranasal sinuses is a rare condition alone, with one case occurring in every 100,000 people. Studies have shown that paranasal sinus tumors tend to occur at an average age between 50 and 60 years [32]. Paranasal sinus cancers from 1999 to 2007 were seen to occur twice as high in males than females [33], while we saw an equal representation of female and male presentations for fibrosarcomas of the paranasal sinuses. Our review found that the most common site for fibrosarcoma of the sinuses was the maxillary sinus, which could be due to the fact that the maxillary sinus is the largest paranasal sinus.
In our review, the most common presenting symptom was nasal obstruction followed by epistaxis and facial fullness/pain. These symptoms are consistent with other cancers of the paranasal sinus. These presenting symptoms are common with many other conditions and can oftentimes be overlooked. The presence of unilateral symptoms that do not improve with treatment should raise the suspicion of a possible mass such as a fibrosarcoma and should warrant further workup [33].

Diagnostic Methods
In routine clinical practice, paranasal fibrosarcoma is commonly misdiagnosed as other neoplasms due to its rarity and non-specific symptomatology. Therefore, it is critical to be familiar with the imaging features that differentiate paranasal fibrosarcoma from other malignancies [5]. Additionally, the rarity of the disease and the relatively few studies within the literature examining the imaging characteristics of PNFS continue to make the preoperative diagnosis of PNFS a challenge [5]. It is also critical that physicians be aware of the advantages and disadvantages of the different imaging modalities. The most common diagnostic method to evaluate a mass of the paranasal sinus area is nasal endoscopy [31]. Histology can additionally aid in further diagnosis. Histological characteristics for fibrosarcoma tend to be consistent with spindle cells that are often arranged in a herringbone pattern with staining for CD34 and vimentin [34], which was seen across many of our cases as seen in Table 2.
When suspecting PNFS, there are particular findings found on certain modalities that may rule in or out other diagnoses on the differential [35]. One study identified the common CT and MRI features seen in patients with confirmed PNFS [5]. This particular study confirmed that PNFS commonly presents as a solitary lobulated or irregular heterogeneous mass, with either well-or ill-defined margins. Furthermore, there should be increased suspicion of PNFS when the well-or ill-defined paranasal neoplasm appears mildly hypointense on T2-weighted MRI that also shows bone destruction and a heterogeneous delayed contrast enhancement pattern [5]. These common features of PNFS emphasize the importance of radiographic findings to arrive at the diagnosis of this already rare and complex disease process.

Treatment and Mortality
An accepted mainstay treatment of fibrosarcoma of the sinuses currently does not exist. It is important to recognize that local recurrence is common for PNFS, and distant metastasis rarely occurs as well. According to analyzed studies, the most commonly used type of treatment was surgical management, as shown in Table 3. This could be due to the local destructive feature of fibrosarcomas as opposed to a metastatic nature [22]. Some studies suggest radiotherapy along with surgical management improves survival rates [22]. While other studies recommend surgery as the mainstay of treatment, with radiotherapy for more malignant tumors, as reflected by the results of this study [23,26]. Due to the frequent local recurrent nature of fibrosarcomas, some studies recommended a wide local excision with an extensive surgical border [1,14,22]. It is also worth mentioning the use of endoscopic surgery as opposed to open surgeries. While some studies suggest the use of endoscopic surgeries due to the decreased surgical complications and length of stay, other studies disapprove of the use of endoscopic surgeries due to the extensive regional nature of the tumor.
Additional research is required to give a definitive statement on indications and contraindications in the use of endoscopic surgeries in fibrosarcoma removal. According to the analyzed studies, it is suggested that surgeons are opting to mainly treat with surgical management as opposed to a multimodal type of management. We recommend that surgeons approach fibrosarcomas with local excision and large surgical border, followed by chemotherapy and radiotherapy, especially if the tumor cannot be fully removed or if surgical border involvement on pathology report is revealed. In addition, for tumors that are unresectable, it is suggested that preoperative chemotherapy should be used to decrease tumor size followed by resection.
Our results suggest that PNFS is associated with a high rate of mortality, with death occurring within one year of treatment in 35% (n = 18) of cases. However, mortality information was only available for 47% (n = 52) of patient cases. Studies that include long-term patient outcomes are needed to better assess PNFS prognosis. Published data have suggested that prognosis is associated with the degree of histological differentiation [18]. Similarly, additional studies on the rate of PNFS reoccurrence are needed. Past reviews have suggested a high rate of PNFS reoccurrence, but the studies in this review did not include sufficient prognostic data [3]. Once these data are included, conclusions on which treatments are associated with favorable outcomes can be made.

Limitations
There are several notable limitations worth mentioning. Since there were no prospective studies found, all data are based on retrospective research. Additionally, the majority of studies were case studies and series, and there were no randomized controlled trials comparing various treatment approaches, making it difficult to compare the efficacies of treatment approaches. The use of solely one primary treatment was not explicitly in the articles, which may skew the results. The mortality data were gathered from sources that mentioned any mortality information within the article. Since timeframes varied greatly for reporting the death and postoperative prognosis of patients, the mortality results may be skewed. Furthermore, the reporting of larger studies oftentimes grouped varying tumors as well as locations other than the paranasal sinuses in analysis, making some data difficult to extract. Across studies, there was not a uniform way in which data were presented, causing some information to be unavailable. To address these limitations, it would be important for larger and more standardized studies to further support our findings. Furthermore, more consistent reporting of patient progress following treatment will help with the assessment of optimal treatment options.

Conclusions
Fibrosarcoma of the paranasal sinuses is a rare but dangerous disease. By conducting this study, we aim to provide physicians with a comprehensive review to assist in the management of PNFS. Physicians should maintain a high index of suspicion when presented with a patient with non-specific symptoms, such as nasal obstruction and facial fullness and pain, which are unresolved. Nasal endoscopy can be utilized to visualize the mass, and the use of CT and MRI can aid in further diagnosis. Ultimately, histology can confirm the final diagnosis. The mainstay of treatment is surgical excision with the use of radiation or chemotherapy depending on resectability and surgical borders. With a high rate of mortality, early identification and treatment are essential.

Conflicts of interest:
In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.