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Objective To investigate the clinical and pathological characteristics of the extrapleural solitary fibrous tumor and the relevant differential diagnosis.Methods HE and immunohistochemical staining were performed on 26 samples of isolated fibrous tumors outside the pleura,and a comprehensive analysis was conducted based on the clinical and imaging data.Results The histological morphology of isolated fibrous tumors was diverse,with typical cases showing the irregular arrangement of oval or spindle shaped cells.In the stroma,thick collagen bands,antler like blood vessels,and peritubular transparent degeneration could be seen.The immunohistochemical staining demonstrated that the positive rates of STAT-6、CD34、Bcl-2、CD99、SMA were 96.2% 、92.3% 、92.3% 、76.9% and 26.9%,respectively.Conclusion SFT commonly occurs in the pleura and can also occur in other areas.Its histological characteristics and immunohistochemical phenotype help to clarify the diagnosis.However,when it occurs in uncommon anatomical sites,it is necessary to carefully and meticulously distinguish and comprehensively judge the clinical prognosis of key diseases that need to be distinguished or excluded..
RESUMEN
Objective To explore MRI manifestations of extrapleural solitary fibrous tumor(SFT)and to analyze the reasons of misdiagnosis.Methods MRI data of 9 cases with extrapleural SFT proved by pathology were analyzed retrospectively.Lesions location, size,shape,intensity,degrees and patterns of enhancement were assessed,and the imaging features and causes of misdiagnosis were also analyzed.Results Among 9 lesions,1 was located in the right cerebellopontine angle region,2 were in subdural-extramedullary region,4 were in the abdominal cavity and 2 were in the pelvic cavity.7 cases were misdiagnosed before operation including 1 as meningioma, 2 as schwannoma,2 as mesenchymal stem cell tumor,1 as pancreatic carcinoma and 1 as Castleman disease.8 lesions were isointense and 1 was mixed iso-or slightly hyperintense on T1WI.3 lesions were isointense,4 were mixed iso-or slightly hyperintense and 2 were mixed slightly hyperintense,iso-or hypointense on T2WI.3 lesions showed significant homogeneous enhancement after the administration of contrast agent,1 lesion showed varying degrees of enhancement and the enhancement was more remarkable in isointense area on T2WI than peripheral hyperintense area.4 lesions showed heterogeneous peripherial enhancement in the early phase,progressive filling in the late phase and finally remarkable homogeneous enhancement.1 lesion showed predominant peripheral striped enhancement in the early phase,and progressive filling and mildly inhomogeneous enhancement with patchy unenhanced area in the center of the lesion in the late phase.Conclusion The MRI features of extrapleural SFT have certain characteristics.It needs to be carefully diagnosed to improve the diagnostic accuracy.