DISCUSSIONS
The parasagittal sinus and spinal canal are the most prevalent locations
for the bulk of intracranial SFTs, which are dural masses made up mostly
of very thick collagen bands that are produced by fibroblasts. This
patient exhibited SFT coming from the right frontal lobe of the brain.
SFT symptoms can vary, and patients may have a variety of nonspecific
symptoms linked to raised intracranial pressure or the tumor site. There
can be hemiplegia, hearing loss, headaches, nausea, vomiting,
disorientation, and memory issues [9].
An 86-year-old man with SFT, localized to the parietal lobe of the right
side and infiltrating the parietal bone, was described by Sugiyama et
al. [10] as presenting for 1 month with increasing and persistent
motor impairment in the left lower extremities.
In another study, a 30-year-old man was diagnosed with SFT that was
close to the temporal lobe of the right side and thickened the temporal
bone next to it. The patient also exhibited dysarthria and left facial
nerve palsy, as well as lessened muscle power in his left upper and
lower limbs [1, 3]. This patient experienced hemiparesis of the left
arm and left foot in addition to a significant headache, and the SFT was
found to be in the right frontal region. The main cause of headaches and
vertigo is elevated intracranial pressure. Patients in this trial did
not exhibit dysarthria, impaired vision, or symptoms of paralysis of the
facial nerve.
For SFT diagnosis, MRI and CT imaging are crucial. Due to MRI’s
fluctuating signal intensity, differential diagnosis of SFT is
challenging. It’s crucial to distinguish between lymphoma, metastases,
neurofibromas, meningiomas, and schwannomas. Important imaging methods
for diagnosing SFT include CT and MRI.
Intracranial SFTs imaging exhibits a variety of characteristics, and
earlier images have shown that intracranial SFTs are most likely to
develop in or around the venous sinuses, the base of the skull, the
sagittal sinus, the falx cerebri, and the peritentorium cerebelli.
Extraaxial tumors with lobulated or irregular shapes, some of which are
oval or dumbbell-shaped, further identify intracranial SFTs [11].
When compared to gray matter, the SFT generally has isointensity to
slight hyperintensity on T1WI and isointensity on T2WI. In cystic
degeneration and necrosis, T1WI exhibits an isointense mixed signal and
an isointense signal with modest hyperintensity [10]. Additionally,
in situations of necrotic areas and cystic degeneration, T2WI exhibits
slight hyperintensity or mixed signals of isointensity [10].
The tumor looked markedly increased after enhanced MRI, and those who
had cystic degeneration had heterogeneous enhancement [12].
Peritumoral edema is often not harmful.
SFT and meningiomas have comparable imaging characteristics; SFT may be
distinguished from meningiomas using MRS. In SFT, compared to
meningiomas, the relative amounts of choline and myo-inositol are
higher. In addition, Chen et al. [13] demonstrated that SFT/HPC
could be distinguished from meningiomas using the normalized ratio of
apparent diffusion coefficient and sensitive signal intensity in the
tumor. The right fronto-temporal area of the brain experienced SFT in
the currently reported instance, along with signal hyperintensity, dural
thickening, and mass effect as previously documented with an elevated
choline peak on MRI spectroscopy.
SFT is mostly diagnosed by pathological investigation. The tumor tissue
had a high concentration of spindle or polygonal cells, as seen by
histological staining. Typically, there are many blood vessels and
collagen fibers that resemble antlers. Around blood vessels, tumor cells
are organized in concentric rings and can either form depleted or rich
areas [14]. IHC revealed that CD34, vimentin, and STAT6 were
positive for SFT tissues. However, the prognosis of a patient is
frequently predicted by the Ki-67 proliferation index. In the prognosis
assessment of CNS SFT, it has been suggested by several studies that
elevated Ki-67 levels (>5%) lead to adverse prognoses.
Currently, CD34 is thought to be the best marker for SFT. Positive
staining has been observed in 95–100% of patients, yet this tumor can
still exist without CD34. Most individuals with intracranial SFT have
positive STAT6. Due to a rearrangement on chromosome 12q, STAT6 could be
connected to the NAB2-STAT6 gene fusion. Therefore, it is advised that
intracranial SFT be diagnosed by looking for the STAT6 or NAB2-STAT6
fusion gene [1]. On the long arm of chromosome 12, NAB2 and STAT6
are adjacent genes that are transcribed in opposing ways [9]. In
SFT, an intrachromosomal inversion aligns the genes so that they are
transcribed from the NAB2 promoter in the same direction [5],
resulting in nuclear expression of STAT6 that can be seen by IHC
[15].
IHC labeling was used to identify STAT6 expression in cerebral SFT
tissue, and the NAB2-STAT6 fusion gene was successfully identified to be
excellently specific and sensitive. Nuclear STAT6’s have 100%
specificity and 96.6% sensitivity, making STAT6 IHC a highly sensitive
and specific alternative for the NAB2-STAT6 fusion gene.
In the current work, lesional cells showed STAT6 expression. Clinical
pathology and prognosis may be related to various NAB2-STAT6 fusion
mutations. The patient profiled in this study’s SFT tissue was
discovered to be STAT6, CD34, S100, and CK positive, with a KI 67 INDEX
of 6-7%. After surgery, the patient’s tumor did not return.
A high incidence of extracranial and local metastases is a feature of
SFT [15]. Previous research has shown that there is a risk of
recurrence in people with long-term SFT, even ten years after the first
resection. As a result, SFT patients need careful care and continuous
observation. The prognosis and therapy of the tumor presented in this
article need more research because it is an uncommon malignancy.
Retrospective research was conducted on patients who got SFT of the
brain between January 2009 and June 2019 by Yu et al. [15].
According to their findings, the WHO classification was lowered, and
patients who received complete resection along with adjuvant therapies
such as Gamma Knife surgery had longer progression-free survival (PFS).
It should be emphasized that the prior study, which was previously
stated, was done retrospectively, had a limited sample size, and that
its conclusions were skewed due to selection bias. According to the
findings of a multicenter study, postoperative radiotherapy, such as 2D
conventional radiotherapy, 3D conformal radiotherapy, and intensity
modulated radiotherapy, can increase the PFS of patients with SFT very
significantly, regardless of the extent of surgery [15].
It should be emphasized that the current study did not look at how
various radiotherapy procedures affected SFT. Currently, no accepted
treatment standards exist for malignant intracranial SFT.
Malignant intracranial SFT cannot be treated with surgical excision or
postoperative radiation. Tumor angiogenesis and proliferation are
inhibited by Anlotinib, a new multitargeted tyrosine kinase inhibitor
with anticancer and antiangiogenic action [1]. SFT may benefit from
anti-angiogenesis as a possible therapy. Malignant intracranial SFT can
be effectively treated with surgery, radiation, and anlotinib alone
[6]. The current work only covers one instance; thus, more
investigation and bigger RCTs are required to confirm its findings.
Advanced renal carcinoma and a few subtypes of advanced sarcomas of soft
tissue are both approved to be treated with Pazopanib, which is a strong
inhibitor of tyrosine kinase [17]. It should be noted that patients
with metastatic or unresectable SFT are successfully treated with
pazopanib.
The results of the current study revealed that surgical resection is the
best option for treating SFT and that postoperative radiation can
considerably increase patient PFS. For aggressive, incurable, or
metastatic SFT, molecule-targeting therapies like the tyrosine kinase
inhibitors anlotinib and pazopanib are potential options.
Conclusion
SFT is an uncommon tumor. As it is rare but very similar to other common
brain tumors, SFT has a heavy chance of misdiagnosis after imaging. It
should be noted that histopathological examination is essential to
differentiate SFT from other diseases of the CNS. Furthermore, resection
of the complete tumor is the preferred treatment modality for SFT.
Postoperative adjuvant treatment indications have not yet been
clarified. Because of the risk of recurrence, careful follow-up for the
long term, including periodic imaging along with surveillance, is
recommended.
Patient’s perspective
I was very worried, firstly, when I learned that I have a rare type of
cancer, due to which I was having problems. But after surgery, my
symptoms resolved, and I got better. During radiotherapy, I was getting
much better, and after that, I felt myself being normal, and I improved
very much. and I am very thankful to the doctors.
Authors’ contributions
S.M. is a major contributor to concept design, defining intellectual
content, literature search, data acquisition, data analysis, statistical
analysis, manuscript preparation, and manuscript review. A.K.Y. and G.D.
helped in concept, literature search, clinical studies, data
acquisition, data analysis, and manuscript preparation. M.A., R., and
A.K.A. contributed to the definition of intellectual content, data
acquisition, and manuscript review.
Ethical Approval
All procedures performed were according to the ethical standards of the
institutional and/or national research committee and the 1964 Helsinki
Declaration, along alongwith its later amendments or comparable ethical
standards.
Patient consent for publication
Informed consent in written form was obtained from the patient for
publication of the present manuscript, including all data and
accompanying images.
Conflicts of interests
The authors declare that they have no conflicts of interest.
References