Learning objectives
Our aim is to identify and discuss,
with a special focus on differential diagnosis,
solitary fibrous tumors (SFTs) arising in unusual localizations with their clinical presentations.
Background
Solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms commonly arising from the pleura and the peritoneum.
Most of them are benign,
but 10-20% are malignant.
SFTs are defined malignant when histopathological analysis shows at least one among high mitotic activity,
high cellularity,
necrosis,
hemorrhage or pleomorphism.
Typical radiological,
clinical and laboratory characteristics include:
pleural or peritoneal localization
round shape and well-defined margins
increased contrast enhancement
inhomogeneous enhancement directly proportional to the size of lesions (due to central necrosis,
hemorrhage and cystic changes with a patchy...
Findings and procedure details
Wesearched thoughour Institutional databseall biopsy-provendiagnosis of SFTs with atypical presentations (extrapleural and extraperitoneal tumors).
In particular,
we describe3 cases of atypical localizations of SFTs with their CT,
MR,
US and PET characteristics.
CASE 1
Initially misdiagnosed as lymphadenopathy,
this submandibular mass was later confirmed to be a SFT (CD34+,
Bcl2+,
CD99+).
Color Doppler US shows a vascularized hypoechoic mass in the submandibular region.
US-guided core needle biopsywas subsequently performed to confirm the diagnosis.
MRI showed hyperintense mass in CE axial/coronal/sagittal T1W,
mildly hipointense in both...
Conclusion
STSs are rare but extremely heterogeneous tumors with a wide spectrum of clinical and radiological presentations.
The majority of STSs are not locally invasive,
however,
a subset of STSs does show invasiveness and metastatic potential.
Being aware of atypical locations allows the radiologist to include potentially invasive tumors like SFTs in the differential diagnosis of extra-pleural/peritoneal soft tissue lesions.
Even though the final diagnosis relies on histopathological analysis,
radiologists play a fundamental role in the diagnosis of SFTs through initial identification,
biopsy guidance,
surgery planning,...
References
1.Zhanlong M,
Haibin S,
Xiangshan F,
Jiacheng S,
Yicheng N.
Variable solitary fibrous tumor locations: CT and MR imaging features.
Medicine (Baltimore) 2016;95:e3031.
doi:10.1097/MD.0000000000003031.